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17/125 Oracle PLSQL: Handling Nulls in IF Statement
 
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Learn Oracle PLSQL EXAM 1Z0-144
Views: 1316 khaled alkhudari
26. IS NULL and IS NOT NULL in SQL (Hindi)
 
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Please Subscribe Channel Like, Share and Comment Visit : www.geekyshows.com
Views: 22225 Geeky Shows
SQL Server 26 - PRIMARY KEY, NOT NULL, UNIQUE
 
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In the last video we created our first table, but I want to give SQL Server some extra information so the database knows more about each of the columns. The first thing is to establish the primary key. To do this all we do is add PRIMARY KEY after the column we want to be the primary key. Simple enough. When we add a constraint right after the column like this, it is often called a column attribute. CREATE TABLE Animals( ID INT PRIMARY KEY, Name VARCHAR(50), Species VARCHAR(50) ); Additionally, if you are using an ID column, it is best to have it labeled as the IDENTITY column. That way, SQL Server will automatically increment the number. CREATE TABLE Animals( ID INT PRIMARY KEY IDENTITY, Name VARCHAR(50), Species VARCHAR(50) ); The other attributes we've discussed in this series are NOT NULL and UNIQUE. We can make the name NOT NULL and the species NOT NULL. We don't have a good column for UNIQUE, so let's add one: CREATE TABLE Animals( ID INT PRIMARY KEY IDENTITY, Name VARCHAR(50) NOT NULL, Species VARCHAR(50) NOT NULL, ContactEmail VARCHAR(50) NOT NULL UNIUQE ); You can see that it is very easy to add multiple column attributes to a column. Just separate them by spaces. The order does not matter. Also, when you say primary key the column is automatically NOT NULL and UNIQUE. There are other attributes you can use including DEFAULT, FOREIGN KEY, and SPARSE. DEFAULT will give a value for a column if you do not put anything in yourself. Foreign keys are used to reference other columns. SPARSE is an attribute we haven't discussed. You can use SPARSE if most of the rows are going to have a NULL for a column and it saves storage space, but we will worry about that in another video. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Support me! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 5373 Caleb Curry
IS NOT NULL, IS NULL, NVL FUNCTION in oracle sql
 
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Oracle sql tutorial, How to select, retrieve rows with null values, not null values and NVL function in oracle SQL
Oracle SQL Tutorial 13 - How to Add Column Constraints (Attributes)
 
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So far, we have this table declaration: CREATE TABLE users( user_id NUMBER, username VARCHAR(50 CHAR) first_name VARCHAR2(50 CHAR), last_name VARCHAR2(50 CHAR) ) We can run this command see that it works. As we are learning though, we are going to want to be able to recreate our table with different settings and such, but if you try to run this command, it will complain that the table already exists. So we first need to delete this table before we start editing settings. When we get more experienced, we will learn about ways to edit the structure of a table that already exists. To fix this, we can get rid of the table using the DROP TABLE command: DROP TABLE users You can run this every time if you need to practice by adding a semicolon after it. This is how you can tell Oracle that you are putting in another command after it. This is known as a delimiter. When you run the script, it is going to run both commands. Now we can go through and reconsider our table structure. This is fine for starting out because we don't have any important data in our database, but once your database is in production you are not going to want to just drop tables. In the last video we discussed different constraints that you can apply to columns in a database table, but how do you actually apply these when you are creating a table? The first way you define constraints is to put them right after the column in your CREATE TABLE statement. CREATE TABLE users( username VARCHAR2(50 CHAR) NOT NULL ) When we define constraints this way, we usually say we are adding column attributes. If you have two constraints you want to add, you just put one after the other with spaces in between. There is no particular order that is required. CREATE TABLE users( username VARCHAR2(50 CHAR) NOT NULL UNIQUE ) In this situation we have already given the column the NOT NULL and UNIQUE attributes, so we should consider making this a primary key: CREATE TABLE users( username VARCHAR2(50 CHAR) PRIMARY KEY ) As you can see, adding column attributes is super easy. We can add a default like this: CREATE TABLE users( username VARCHAR2(50 CHAR) PRIMARY KEY, account_balance NUMBER DEFAULT 0 ) Note that now we need the comma after the first row. There are a few constraints we did not talk go through an example, specifically foreign keys and check constraints. We will be adding these constraints to our database in future videos. In the mean time, I have a thought for you… Many people prefer to name their column constraints. That way, we can refer to certain constraints by name. For example, we might have a primary key constraint that could be named users_pk. The way we are creating these constraints does not allow for this feature, so in the next video we are going to be discussing different ways to create constraints. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Support me on Patreon! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 22621 Caleb Curry
COALESCE Function in SQL ORACLE Query With Example
 
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ORACLE/PLSQL: COALESCE FUNCTION The Oracle/PLSQL COALESCE function returns the first non-null expression in the list. If all expressions evaluate to null, then the COALESCE function will return null. The syntax for the Oracle/PLSQL COALESCE function is: coalesce( expr1, expr2, ... expr_n ) PARAMETERS: expr1 to expr_n are the expressions to test for non-null values. EXAMPLE: The COALESCE function can be used in Oracle/PLSQL. You could use the coalesce function in a SQL statement as follows: SELECT COALESCE( address1, address2, address3 ) result FROM suppliers; The above COALESCE function is equivalent to the following IF-THEN-ELSE statement: IF address1 is not null THEN result := address1; ELSIF address2 is not null THEN result := address2; ELSIF address3 is not null THEN result := address3; ELSE result := null; END IF; The COALESCE function will compare each value, one by one. Lets apply the same to emp table. We have some NULL values in comm and mgr columns. but not in any other columns. So lets take a example for this 2 columns. COALESCE(comm,mgr,sal) Here if comm is null, function returns mgr value. If mgr is null it returns sal value! Query used in video: SELECT ename,comm,mgr,sal,COALESCE(comm,mgr,sal) result FROM emp;
Views: 6428 WingsOfTechnology
How to filter Rows with Null Values in Select Statement - SQL Server / TSQL Tutorial Part 110
 
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SQL Server / T-SQL Tutorial Scenario: How to filter Rows with Null Values in Select Statement in SQL Server Let's say that you are working as SQL Server developer. You need to write two queries 1) Return all the records from dbo.Customer table where Address column has Null values 2) Return only the records from dbo.Customer table where Address column has the values other than Null. Link to scripts used in SQL Server / TSQL Tutorial Video http://www.techbrothersit.com/2016/06/how-to-filter-rows-with-null-values-in.html Check out our website for Different SQL Server, MSBI tutorials and interview questions such as SQL Server Reporting Services(SSRS) Tutorial SQL Server Integration Services(SSIS) Tutorial SQL Server DBA Tutorial SQL Server / TSQL Tutorial ( Beginner to Advance) http://www.techbrothersit.com/
Views: 4078 TechBrothersIT
IS NULL Operator in SQL Query with Example
 
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SQL IS NULL Operator: A column value is NULL if it does not exist. The IS NULL operator is used to display all the rows for columns that do not have a value. For Example: If you want to find the emp names who do not get any commision, the query would be as given below: select * from emp where COMM IS NULL; In the opposite way, NOT NULL also works here: select * from emp where COMM IS NOT NULL; Thanks for watching..:)
Views: 3697 WingsOfTechnology
Null: Databases for Developers #10
 
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The null value represents missing or unknown information. But using it brings complications to your SQL. In this video Chris discusses how to work with null to ensure you get the correct results. Further reading: Oracle Database SQL Reference on Nulls: http://docs.oracle.com/database/122/SQLRF/Nulls.htm#SQLRF30037 Null related functions: http://docs.oracle.com/database/122/SQLRF/Single-Row-Functions.htm#SQLRF51187 Is null condition: http://docs.oracle.com/database/122/SQLRF/Null-Conditions.htm#SQLRF52152 Need help with SQL? Ask us over on AskTOM: https://asktom.oracle.com Twitter: https://twitter.com/ChrisRSaxon Daily SQL Twitter tips: https://twitter.com/SQLDaily All Things SQL blog: https://blogs.oracle.com/sql/ ============================ The Magic of SQL with Chris Saxon Copyright © 2015 Oracle and/or its affiliates. Oracle is a registered trademark of Oracle and/or its affiliates. All rights reserved. Other names may be registered trademarks of their respective owners. Oracle disclaims any warranties or representations as to the accuracy or completeness of this recording, demonstration, and/or written materials (the “Materials”). The Materials are provided “as is” without any warranty of any kind, either express or implied, including without limitation warranties or merchantability, fitness for a particular purpose, and non-infringement.
Views: 3311 The Magic of SQL
67 - Oracle PL/SQL Case Statement تعليم أوراكل
 
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by Mohamed El Desouki - محمد الدسوقى [email protected] Tel :00966 553450836 جامعة سلمان بن عبد العزيز - السعودية - الخرج Database 2 - PL/SQL Case Statement in Arabic Text Book: Fundamentals of Database Systems, 5th Edition, by Elmasri/Navathe, published by Addison-W
Oracle Database11g tutorials 13 || SQL substr function / SQL substring function
 
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link of SQL substr blog : http://www.rebellionrider.com/SQL-substr-function.htm SQL substr function SQL Substr function will return a sub string of a specified length from the source string beginning at a given position. Tool used in this tutorial is command prompt. This tutorial series is part of SQL expert exam certification training. if you are preparing for SQL certification you can use my tutorials. This SQL Tutorial is a part of free training. Copy Cloud referral link || Use this link to join copy cloud and get 20GB of free storage https://copy.com?r=j7eYO7 Contacts E-Mail [email protected] Twitter https://twitter.com/rebellionrider Instagram http://instagram.com/rebellionrider Facebook. https://www.facebook.com/imthebhardwaj Linkedin. http://in.linkedin.com/in/mannbhardwaj/ Thanks for linking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com ---------------------------------------------------------------------------- As the name suggests SQL Substr function will return substring from a given source string. Let's see the Syntax Substr (source_string, start_pos, Substr_length) As we can see SQL substr function takes 3 parameters. First one is Source string from which you want to extract the segment. Second parameter is Starting position for sub string from the Source string. And the third parameter is Substr_length which is the length for the substring. First two parameters are mandatory to specify while third one is optional. So we can say. SQL Substr function will return a sub string of a specified length from the source string beginning at a given position. First parameter source string can be of any data type CHAR, VARCHAR2, NCHAR, NVARCHAR2, CLOB, or NCLOB whereas both start_pos, Substr_length parameters must be number data type. The returning result of SQL Substr function is of same data type of source string. Let's see an example of SQL Substr function. SELECT substr('www.RebellionRider.com',5,14) FROM dual; Here in this query url of my website www.RebellionRider.com is our source string with the total length of 22 characters, Now, I want to extract the name of my website that is, RebellionRider. So if you count the total length of the name of the website, it is 14. That's why I have specified 14 as my third parameter of SQL Substr function which is substr_length. Also the name of the website RebellionRider is starting from 5th position therefore I have specified 5 at second parameter of SQL substr function which is strt_pos or starting position. Execute it. Here is our result RebellionRider When starting position is larger than the length of source string. In this case SQL Substr function will return NULL as a result. Let's do an example. SELECT substr('www.RebellionRider.com',23,14) FROM dual; As you can see here I have specified 23 at starting position and the total length of our source string is 22 characters Let's execute And the result is Null. Second scenario When the Substr_length is greater than source string In this case the segment return is the substring from starting position to the end of the string. For example SELECT substr('www.RebellionRider.com',5,23) FROM dual; Our starting position is at 5 means at the first R of RebellionRider and length of substring is set to 23 which is greater than the length of source string that is 22. Execute. As you can see we get a substring from first R of RebellionRider till the end of the source String. Third scenario When you supply numeric or arithmetic expression or a DATE instead of character as Source string to SQL Substr function In this scenario If you have supplied a numeric string instead of character as source string, the oracle engine casts them as a character when they occur as parameter to SQL Substr function. And if you have supplied Arithmetic expression or a DATE then The Oracle engine first solves or evaluates the Arithmetic expression or the DATE Then casts them as a character. Means if you have arithmetic expression in your source string then oracle will first solve it and then change or say cast the value of its result into character. Let's see some example. SELECT substr(50000-7,2,4) FROM dual; Oracle first evaluates the arithmetic expression that is 50000-7 equals to 49993. And then oracle engine casts this result 49993 into a character string. Means 49993 will be a 5 characters string. Starting position of substring is 2, that means from the first 9 of 49993 We specified the length of substring is 4 so we must get 9993 as our result. Let's check execute
Views: 81887 Manish Sharma
Tutorial 44 : NULL in Oracle || NVL() Explained
 
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Hi Friends! Here we are learning about what is NULL in Oracle. How we can deal with NULL Values. How NVL() Function helps us with NULL Value. Hope the concept and example would be clear to you. For any help or issue, let me know in comment box. Thanks, Happy Coding.
Views: 91 YourSmartCode
NVL2 Function in SQL Query
 
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NVL2(): The Oracle NVL2 function extends the functionality found in the NVL function. It lets you substitutes a value when a null value is encountered as well as when a non-null value is encountered. Syntax: NVL2( string1, value_if_NOT_null, value_if_null ) Arguments: string1 is the string to test for a null value. value_if_NOT_null is the value returned if string1 is not null. value_if_null is the value returned if string1 is null. Queries used in video: select ename, NVL2(mgr,'Yes','No Manager') from emp; select ename,sal,NVL2(comm,'Has some value here','No Value') from emp;
Views: 1614 WingsOfTechnology
Oracle Forms || Post-Query & Pre-Query Triggers || Bangla (23)
 
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Oracle Forms || Post-Query & Pre-Query Triggers || Bangla (23) To See More Forms Tutorial Click here https://www.youtube.com/watch?v=Zsu4CWo_vwk&list=PLXXvCMuixAJU3Ap_FE2zSEBicv8IC5kDU To See More Reports Tutorial Click here https://www.youtube.com/watch?v=y_0f_iILlmY&list=PLXXvCMuixAJUfU4ZISmPtHrmKe5qRvyVY Dear viewer, In this tutorial you will learn how to create POST-QUERY & PRE-QUERY Trigger. I have giving example code here. POST-QUERY: SELECT DEPARTMENT_NAME INTO :EMPLOYEES.DEPT_NAME FROM DEPARTMENTS WHERE DEPARTMENT_ID=:EMPLOYEES.DEPARTMENT_ID; PRE-QUERY: IF :EMPLOYEES.COMMISSION_PCT IS NULL AND :EMPLOYEES.MANAGER_ID IS NULL THEN MESSAGE('YOU MUST QUERY BY COMMISSION AND MANAGER ID.'); MESSAGE('YOU MUST QUERY BY COMMISSION AND MANAGER ID.'); RAISE FORM_TRIGGER_FAILURE; END IF; To Get more Tutorial Subscribe The Channel click here https://www.youtube.com/channel/UCQ3ea4zVCfnKBx1_7h8raGQ?sub_confirmation=1 To Get All Post Like The Facebook Page Click here https://www.facebook.com/oracledbsolutions Follow us: Facebook: https://www.facebook.com/oracledbsolutions Youtube link: https://www.youtube.com/channel/UCQ3ea4zVCfnKBx1_7h8raGQ?view_as=subscriber Facebook Group: https://www.facebook.com/groups/465557066961548 Contact us: email: [email protected] Skype: oracle26solutions Mob: 01734557080, 01627422780
Views: 347 OracleDB Solutions
SQL tutorial 74: SQL COALESCE Function In oracle Database Manish Sharma
 
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Third tutorial in SQL Null Series. Coalesce Null function with example in oracle Database. ------------------------------------------------------------------------ ►►►LINKS◄◄◄ Blog : http://bit.ly/sql-coalesce Previous Tutorial ► NVL https://youtu.be/aRoTR5Jn6K0 ► NVL2 https://youtu.be/SCwc0HcS1-U ------------------------------------------------------------------------- ►►►Let's Get Free Uber Cab◄◄◄ Use Referral Code UberRebellionRider and get $20 free for your first ride. ------------------------------------------------------------------------- ►►►Help Me In Getting A Job◄◄◄ ►Help Me In Getting A Good Job By Connecting With Me on My LinkedIn and Endorsing My Skills. All My Contact Info is Down Below. You Can Also Refer Me To Your Company Thanks -------------------------------------------------------------------------- ►Make sure you SUBSCRIBE and be the 1st one to see my videos! -------------------------------------------------------------------------- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ►►►Find me on Social Media◄◄◄ Follow What I am up to as it happens on https://twitter.com/rebellionrider https://www.facebook.com/imthebhardwaj http://instagram.com/rebellionrider https://plus.google.com/+Rebellionrider http://in.linkedin.com/in/mannbhardwaj/ http://rebellionrider.tumblr.com/ http://www.pinterest.com/rebellionrider/ You can also Email me at for E-mail address please check About section Please please LIKE and SHARE my videos it makes me happy. Thanks for liking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com ♥ I LOVE ALL MY VIEWERS AND SUBSCRIBERS
Views: 27681 Manish Sharma
Handling NULL using NVL , NVL2
 
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If a column in a row has no value, then the column is said to be null, or to contain null. Nulls can appear in columns of any datatype that are not restricted by NOT NULL or PRIMARY KEY integrity constraints. Use a null when the actual value is not known or when a value would not be meaningful. Oracle Database treats a character value with a length of zero as null. However, do not use null to represent a numeric value of zero, because they are not equivalent. -Nulls in SQL Functions NVL NVL2 NULLIF COALESCE Follow the steps given in video : https://youtu.be/FtZ8RhTbaYM and Learn How to handle NULL using NULL handling Function.
Views: 329 Oracle Tutorial
DECODE Function ( IF..THEN..ELSE) in SQL ORACLE Query With Example
 
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ORACLE/PLSQL: DECODE FUNCTION The Oracle/PLSQL DECODE function has the functionality of an IF-THEN-ELSE statement. The syntax for the Oracle/PLSQL DECODE function is: DECODE( expression , search , result [, search , result]... [, default] ) ARGUMENTS: expression is the value to compare. search is the value that is compared against expression. result is the value returned, if expression is equal to search. default is optional. If no matches are found, the DECODE function will return default. If default is omitted, then the DECODE function will return null (if no matches are found). Lets apply this function on emp table. Emp table has 3 dept numbers like 10,20 and 30. So if I want to display the different dept names based on ID, I have to use IF THEN ELSE condition. IF deptno=10 THEN "DEPT1" ELSE deptno=20 THEN "DEPT2" ELSE deptno=30 THEN "DEPT3" This entire IF block can be achived using single DECODE(). DECODE(deptno,10,'DEPT1',20,'DEPT2',30,'DEPT3') Query used in Video: select empno,ename,deptno,DECODE(deptno,10,'DEPT1',20,'DEPT2',30,'DEPT3') from emp;
Views: 5607 WingsOfTechnology
CASE Function( IF..THEN..ELSE) in SQL ORACLE Query With Example
 
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ORACLE/PLSQL: CASE STATEMENT The Oracle/PLSQL CASE statement has the functionality of an IF-THEN-ELSE statement. Starting in Oracle 9i, you can use the CASE statement within a SQL statement. The syntax for the Oracle/PLSQL CASE statement is: CASE [ expression ] WHEN condition_1 THEN result_1 WHEN condition_2 THEN result_2 ... WHEN condition_n THEN result_n ELSE result END --------- ARGUMENTS: expression is optional. It is the value that you are comparing to the list of conditions. (ie: condition_1, condition_2, ... condition_n) condition_1 to condition_n must all be the same datatype. Conditions are evaluated in the order listed. Once a condition is found to be true, the CASE statement will return the result and not evaluate the conditions any further. result_1 to result_n must all be the same datatype. This is the value returned once a condition is found to be true. NOTE: If no condition is found to be true, then the CASE statement will return the value in the ELSE clause. If the ELSE clause is omitted and no condition is found to be true, then the CASE statement will return NULL. You can have up to 255 comparisons in a CASE statement. Each WHEN ... THEN clause is considered 2 comparisons. Lets apply this function on emp table. Emp table has 3 dept numbers like 10,20 and 30. So if I want to display the different dept names based on ID, I have to use IF THEN ELSE condition. IF deptno=10 THEN "DEPT1" ELSE deptno=20 THEN "DEPT2" ELSE deptno=30 THEN "DEPT3" This entire IF block can be achived using CASE. CASE deptno WHEN 10 THEN 'DEPT1' WHEN 20 THEN 'DEPT2' WHEN 30 THEN 'DEPT3' ELSE 'NO DEPT' END; Query used in Video: select empno,ename,deptno,CASE deptno WHEN 10 THEN 'DEPT1' WHEN 20 THEN 'DEPT2' WHEN 30 THEN 'DEPT3' ELSE 'No Dept' END from emp;
Views: 16656 WingsOfTechnology
Oracle SQL Lecture 28: IS NULL and IS NOT NULL
 
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Oracle SQL: IS NULL and IS NOT NULL https://www.youtube.com/channel/UCnBpiBIOtRgMsk4G7Ri1jbQ
Views: 747 Oracle SQL
Oracle SQL The Delete Statement تعليم أوراكل
 
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by Mohamed El Desouki - محمد الدسوقى [email protected] Tel :00966 553450836 جامعة سلمان بن عبد العزيز - السعودية - الخرج How to delete data from tables. كيف تحذف بيانات من الجدول Text Book: Fundamentals of Database Systems, 5th Edition, by Elmasri/Navathe, published by Addison-W oracle create table statement oracle drop table statement oracle constraints database constraints primary key constraint foreign key constraint check constraint null not null constraint unique constraint insert into statement update statement delete statement
Differences between ISNULL and NULLIF - sql server interview questions
 
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Hi friends, in this session I am gonna discuss the differences between ISNULL and NULLIF. Both ISNULL and NULLIF are built in system functions in sql server. Lot of people get confused between these 2 system functions. Lets discuss about each of these system functions separately so that you will get better idea. 1st lets discuss about ISNULL. ISNULL: ISNUL is a system function which replaces NULL with the specified replacement value. The functionalityof ISNULL is : 1. 1st it will Evaluate the expression which is in parameter 1. 2. it will compare the evaluated expression with null. if the paramter 1 = NULL ? 3. If parameter1 is equal to null i.e., if parameter 1 is null, then isnull function returns replacement value. if parameter1is not NULL, then ISNULL function returns parameter1 I hope we are clear on ISNULL. Lets move on to the next system function, that is NULLIF. NULLIF: NULLIF is a system function which returns a null value if the two specified expressions are equal. The functionalityof NULLIF is : 1. 1st it will Evaluate both the expression which are in parameter 1 and parameter 2. 2. next it will compare both the evaluated expressions with null. 3. If both the expressions are equal, the nullif functions returns NULL. 4. If both the expressions are not equal, the nullif functions returns 1st expression. Lets conclude the discussion with the similarities and differences between ISNULL and NULLIF Similarities: Both ISNULL and NULLIF are system functions. Syntax for Both the functions are similar Both ISNULL and NULLIF functions accepts 2 input parameters. Differences: isnull function compares 1st parameter with null.where as nullif function compares 1st parameter with 2nd parameter ISNULL function returns 2nd paramter if the 1st parameter isnull. nullif function returns null is 1st parameter = 2nd paramter. ISNULL function returns 1st paramter if the 1st parameter is not null. nullif function returns 1st paramter if 1st parameter is not equal to 2nd paramter. Thanks for watching this video. Bye , Have a good Day
Views: 7725 TheSSScreations
Oracle Database | Bangla Tutorials 23 :: Constraint Not null
 
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www.facebook.com/oracle.shohag Email : [email protected] Website : www.oraclebangla.com Topics : Constraint Not null
Views: 992 Oracle Bangla
PL/SQL tutorial 9: IF THEN ELSE (IF-ELSE) Statement in PL/SQL by Manish Sharma
 
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3rd tutorial in the series explaining IF-THEN-ELSE statement in Oracle PL/SQL with Example. Enjoy ------------------------------------------------------------------------ ►►►LINKS◄◄◄ Blog : http://bit.ly/if-then-else Previous Tutorial ► IF THEN Statement https://youtu.be/IWvuFD6eD30 ------------------------------------------------------------------------- ►►►Let's Get Free Uber Cab◄◄◄ Use Referral Code UberRebellionRider and get $20 free for your first ride. ------------------------------------------------------------------------- ►►►Help Me In Getting A Job◄◄◄ ►Help Me In Getting A Good Job By Connecting With Me on My LinkedIn and Endorsing My Skills. All My Contact Info is Down Below. You Can Also Refer Me To Your Company Thanks ------------------------------------------------------------------------- ►Make sure you SUBSCRIBE and be the 1st one to see my videos! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ►►►Find me on Social Media◄◄◄ Follow What I am up to as it happens on https://twitter.com/rebellionrider https://www.facebook.com/imthebhardwaj http://instagram.com/rebellionrider https://plus.google.com/+Rebellionrider http://in.linkedin.com/in/mannbhardwaj/ http://rebellionrider.tumblr.com/ http://www.pinterest.com/rebellionrider/ You can also Email me at for E-mail address please check About section Please please LIKE and SHARE my videos it makes me happy. Thanks for liking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com ♥ I LOVE ALL MY VIEWERS AND SUBSCRIBERS
Views: 65123 Manish Sharma
IN VS EXISTS VS JOIN, performance
 
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This video demonstrates the performance effects of using an exists clause instead of an IN clause, also it shows how we can update a simple sub query having an IN clause with an EXISTS or JOIN statement. It also shows that joining would consider the null data, where as an IN clause would neglect null values. If you want more such videos of exciting and amazing 'difference between' concepts, check out the links below : union and union all : https://youtu.be/n9FqQOd8liY char and varchar2 : https://youtu.be/039qzwjWf4k replace and translate : https://youtu.be/HKYF77BGzOE procedure and function : https://youtu.be/q3LmOenL120 rank and dense_rank : https://youtu.be/WGSX998hZ9M delete and truncate : https://youtu.be/u76wMm2byXo %type and %rowtype : https://youtu.be/MlLUFeZ_3eM
Views: 12721 Kishan Mashru
Oracle Select Statement تعليم أوراكل
 
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by Mohamed El Desouki - محمد الدسوقى [email protected] Tel :00966 553450836 جامعة سلمان بن عبد العزيز - السعودية - الخرج How to Retrieve Data using Select statement. Select كيفية إسترجاع البيانات بإستخدام Text Book: Fundamentals of Database Systems, 5th Edition, by Elmasri/Navathe, published by Addison-W oracle create table statement oracle drop table statement oracle constraints database constraints primary key constraint foreign key constraint check constraint null not null constraint unique constraint insert into statement update statement delete statement select statement basic query
Dynamic SQL in Stored Procedure
 
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In this video we will discuss, using dynamic sql in a stored procedure and it's implications from sql injection perspective. We will discuss performance implications of using dynamic sql in a stored procedure in a later video. Text version of the video http://csharp-video-tutorials.blogspot.com/2017/04/dynamic-sql-in-stored-procedure.html Slides http://csharp-video-tutorials.blogspot.com/2017/04/dynamic-sql-in-stored-procedure_11.html All SQL Server Text Articles http://csharp-video-tutorials.blogspot.com/p/free-sql-server-video-tutorials-for.html All SQL Server Slides http://csharp-video-tutorials.blogspot.com/p/sql-server.html All SQL Server Tutorial Videos https://www.youtube.com/playlist?list=PL08903FB7ACA1C2FB All Dot Net and SQL Server Tutorials in English https://www.youtube.com/user/kudvenkat/playlists?view=1&sort=dd All Dot Net and SQL Server Tutorials in Arabic https://www.youtube.com/c/KudvenkatArabic/playlists Consider the following stored procedure "spSearchEmployees". We implemented this procedure in Part 139 of SQL Server tutorial. This stored procedure does not have any dynamic sql in it. It is all static sql and is immune to sql injection. Create Procedure spSearchEmployees @FirstName nvarchar(100) = NULL, @LastName nvarchar(100) = NULL, @Gender nvarchar(50) = NULL, @Salary int = NULL As Begin Select * from Employees where (FirstName = @FirstName OR @FirstName IS NULL) AND (LastName = @LastName OR @LastName IS NULL) AND (Gender = @Gender OR @Gender IS NULL) AND (Salary = @Salary OR @Salary IS NULL) End Go Whether you are creating your dynamic sql queries in a client application like ASP.NET web application or in a stored procedure, you should never ever concatenate user input values. Instead you should be using parameters. Notice in the following example, we are creating dynamic sql queries by concatenating parameter values, instead of using parameterized queries. This stored procedure is prone to SQL injection. Let's prove this by creating a "Search Page" that calls this procedure. Create Procedure spSearchEmployeesBadDynamicSQL @FirstName nvarchar(100) = NULL, @LastName nvarchar(100) = NULL, @Gender nvarchar(50) = NULL, @Salary int = NULL As Begin Declare @sql nvarchar(max) Set @sql = 'Select * from Employees where 1 = 1' if(@FirstName is not null) Set @sql = @sql + ' and FirstName=''' + @FirstName + '''' if(@LastName is not null) Set @sql = @sql + ' and LastName=''' + @LastName + '''' if(@Gender is not null) Set @sql = @sql + ' and Gender=''' + @Gender + '''' if(@Salary is not null) Set @sql = @sql + ' and Salary=''' + @Salary + '''' Execute sp_executesql @sql End Go Add a Web Page to the project that we have been working with in our previous video. Name it "DynamicSQLInStoredProcedure.aspx". Copy and paste the HTML and code available on my blog at the following link http://csharp-video-tutorials.blogspot.com/2017/04/dynamic-sql-in-stored-procedure.html At this point, run the application and type the following text in the "Firsname" text and click "Search" button. Notice "SalesDB" database is dropped. Our application is prone to SQL injection as we have implemented dynamic sql in our stored procedure by concatenating strings instead of using parameters. ' Drop database SalesDB -- In the following stored procedure we have implemented dynamic sql by using parameters, so this is not prone to sql injecttion. This is an example for good dynamic sql implementation. Create Procedure spSearchEmployeesGoodDynamicSQL @FirstName nvarchar(100) = NULL, @LastName nvarchar(100) = NULL, @Gender nvarchar(50) = NULL, @Salary int = NULL As Begin Declare @sql nvarchar(max) Declare @sqlParams nvarchar(max) Set @sql = 'Select * from Employees where 1 = 1' if(@FirstName is not null) Set @sql = @sql + ' and [email protected]' if(@LastName is not null) Set @sql = @sql + ' and [email protected]' if(@Gender is not null) Set @sql = @sql + ' and [email protected]' if(@Salary is not null) Set @sql = @sql + ' and [email protected]' Execute sp_executesql @sql, N'@FN nvarchar(50), @LN nvarchar(50), @Gen nvarchar(50), @sal int', @[email protected], @[email protected], @[email protected], @[email protected] End Go On the code-behind page, use stored procedure spSearchEmployeesGoodDynamicSQL instead of spSearchEmployeesBadDynamicSQL. We do not have to change any other code. At this point run the application one more time and type the following text in the "Firstname" textbox and click the "Search" button. ' Drop database SalesDB -- Notice "SalesDB" database is not dropped, So in this case our application is not succeptible to SQL injection attack. Summary : Whether you are creating dynamic sql in a client application (like a web application) or in a stored procedure always use parameters instead of concatnating strings. Using parameters to create dynamic sql statements prevents sql injection.
Views: 34906 kudvenkat
CASE STATEMENT(IF THEN ELSE) IN ORACLE SQL WITH EXAMPLE
 
06:28
The case statement gives the if-then-else kind of conditional ability to the otherwise static sql select statement, This video demonstrates how to write an case statement in oracle sql, and explains different aspects of the case statement. The video explains the execution flow of the case statement and advises on the best way to write one.
Views: 2330 Kishan Mashru
AskTOM TV - not null... I mean *really* not null
 
04:09
A short video to help you understand the "thought process" behind answering AskTom questions. blog: https://connor-mcdonald.com ========================================­­­­============== Copyright © 2017 Oracle and/or its affiliates. Oracle is a registered trademark of Oracle and/or its affiliates. All rights reserved. Other names may be registered trademarks of their respective owners. Oracle disclaims any warranties or representations as to the accuracy or completeness of this recording, demonstration, and/or written materials (the “Materials”). The Materials are provided “as is” without any warranty of any kind, either express or implied, including without limitation warranties or merchantability, fitness for a particular purpose, and non-infringement.
Views: 754 Connor McDonald
SQL: WITH Clause
 
06:11
In this tutorial, you'll learn will learn how to use with clause PL/SQL (Procedural Language/Structured Query Language) is Oracle Corporation's procedural extension for SQL and the Oracle relational database. PL/SQL is available in Oracle Database (since version 7), TimesTen in-memory database (since version 11.2.1), and IBM DB2 (since version 9.7).[1] Oracle Corporation usually extends PL/SQL functionality with each successive release of the Oracle Database. PL/SQL includes procedural language elements such as conditions and loops. It allows declaration of constants and variables, procedures and functions, types and variables of those types, and triggers. It can handle exceptions (runtime errors). Arrays are supported involving the use of PL/SQL collections. Implementations from version 8 of Oracle Database onwards have included features associated with object-orientation. One can create PL/SQL units such as procedures, functions, packages, types, and triggers, which are stored in the database for reuse by applications that use any of the Oracle Database programmatic interfaces. PL/SQL works analogously to the embedded procedural languages associated with other relational databases. For example, Sybase ASE and Microsoft SQL Server have Transact-SQL, PostgreSQL has PL/pgSQL (which emulates PL/SQL to an extent), and IBM DB2 includes SQL Procedural Language,[2] which conforms to the ISO SQL’s SQL/PSM standard. The designers of PL/SQL modeled its syntax on that of Ada. Both Ada and PL/SQL have Pascal as a common ancestor, and so PL/SQL also resembles Pascal in several aspects. However, the structure of a PL/SQL package does not resemble the basic Object Pascal program structure as implemented by a Borland Delphi or Free Pascal unit. Programmers can define public and private global data-types, constants and static variables in a PL/SQL package.[3] PL/SQL also allows for the definition of classes and instantiating these as objects in PL/SQL code. This resembles usage in object-oriented programming languages like Object Pascal, C++ and Java. PL/SQL refers to a class as an "Abstract Data Type" (ADT) or "User Defined Type" (UDT), and defines it as an Oracle SQL data-type as opposed to a PL/SQL user-defined type, allowing its use in both the Oracle SQL Engine and the Oracle PL/SQL engine. The constructor and methods of an Abstract Data Type are written in PL/SQL. The resulting Abstract Data Type can operate as an object class in PL/SQL. Such objects can also persist as column values in Oracle database tables. PL/SQL is fundamentally distinct from Transact-SQL, despite superficial similarities. Porting code from one to the other usually involves non-trivial work, not only due to the differences in the feature sets of the two languages,[4] but also due to the very significant differences in the way Oracle and SQL Server deal with concurrency and locking. There are software tools available that claim to facilitate porting including Oracle Translation Scratch Editor,[5] CEITON MSSQL/Oracle Compiler [6] and SwisSQL.[7] The StepSqlite product is a PL/SQL compiler for the popular small database SQLite. PL/SQL Program Unit A PL/SQL program unit is one of the following: PL/SQL anonymous block, procedure, function, package specification, package body, trigger, type specification, type body, library. Program units are the PL/SQL source code that is compiled, developed and ultimately executed on the database. The basic unit of a PL/SQL source program is the block, which groups together related declarations and statements. A PL/SQL block is defined by the keywords DECLARE, BEGIN, EXCEPTION, and END. These keywords divide the block into a declarative part, an executable part, and an exception-handling part. The declaration section is optional and may be used to define and initialize constants and variables. If a variable is not initialized then it defaults to NULL value. The optional exception-handling part is used to handle run time errors. Only the executable part is required. A block can have a label. Package Packages are groups of conceptually linked functions, procedures, variables, PL/SQL table and record TYPE statements, constants, cursors etc. The use of packages promotes re-use of code. Packages are composed of the package specification and an optional package body. The specification is the interface to the application; it declares the types, variables, constants, exceptions, cursors, and subprograms available. The body fully defines cursors and subprograms, and so implements the specification. Two advantages of packages are: Modular approach, encapsulation/hiding of business logic, security, performance improvement, re-usability. They support object-oriented programming features like function overloading and encapsulation. Using package variables one can declare session level (scoped) variables, since variables declared in the package specification have a session scope.
Views: 14762 radhikaravikumar
NVL Function in SQL Query
 
04:04
NVL(): The Oracle/PLSQL NVL function lets you substitute a value when a null value is encountered. Syntax: NVL( string1, replace_with ) Arguments: string1 is the string to test for a null value. replace_with is the value returned if string1 is null. Example: Let's look at some Oracle NVL function examples and explore how you would use the NVL function in Oracle/PLSQL. For example: select NVL(comm, 'n/a') from emp; The SQL statement above would return 'n/a' if the 'comm' field contained a null value. Otherwise, it would return the 'comm' value. Lets have a look on emp table. Here for manager and comm columns we have null data. In output, I am getting null values. By using NVL function i can omit these null values in output.
Views: 4975 WingsOfTechnology
SQL Aggregation queries using Group By, Sum, Count and Having
 
10:01
From SQL Queries Joes 2 Pros (Vol2) ch4.1. Learn up to write aggregated queries.
Views: 177891 Joes2Pros SQL Trainings
Oracle NVL Function Explained with Examples
 
09:25
https://www.databasestar.com/oracle-nvl-nvl2-logical-functions/ The Oracle NVL function allows you to check a value and return a different value if that value is NULL. It’s great for using another value if the first one is NULL or an optional value, for example people’s phone numbers. It’s also good alongside aggregate functions and grouping so you can see what the difference is between a subtotal row and an actual NULL value. The syntax of the Oracle NVL function is: NVL( check_value, replace_value ) The parameters are: - check_value (mandatory): This is the value that is displayed to the user. It is also the value that is checked for NULL. - replace_value (mandatory): This is the value that appears if the check_value is NULL. The function can use many different data types as parameters: string, date, or numeric. However, both parameters need to be the same type. For more information about the Oracle NVL function, including all of the SQL shown in this video and the examples, read the related article here: https://www.databasestar.com/oracle-nvl-nvl2-logical-functions/
Views: 507 Database Star
auto increment in sql oracle - ( Auto increment field )
 
03:07
auto increment in sql oracle ----------------------------------------------- CREATE table customers ( customer_id int not null, customer_name varchar(50), primary key (customer_id) ); create sequence customer_id minvalue 1 start with 1 cache 10; insert into customers values(customer_id.nextval,'maxwel'); -- to drop sequence drop sequence customer_id
Views: 7498 Data Disc
Validation Rule: Is Not Null
 
02:30
Validation Rule: Is Not Null
Views: 8406 Perins Elearning
MEC SQL Fundamentals (08 of 13): Using IN, NOT IN, and NULL in an SQL query.
 
05:09
This SQL tutorial shows examples of using IN, NOT IN, and NULL in the WHERE clause of an SQL query. SQL Server Management Studio is used in this video. The standard SQL presented here also applies to other DBMS platforms besides SQL Server. This is part 8 of 13 in this tutorial series. (Search for "kreie Oracle databasetopics" for tutorials using Oracle software.)
Views: 738 databaseMEC
Oracle SQL The Update Statement تعليم أوراكل
 
10:54
by Mohamed El Desouki - محمد الدسوقى [email protected] Tel :00966 553450836 جامعة سلمان بن عبد العزيز - السعودية - الخرج How to update and modify existing data in a table. كيف تحدث بيانات موجودة فى الجدول Text Book: Fundamentals of Database Systems, 5th Edition, by Elmasri/Navathe, published by Addison-W oracle create table statement oracle drop table statement oracle constraints database constraints primary key constraint foreign key constraint check constraint null not null constraint unique constraint insert into statement update statement delete statement
Constraint In Oracle PL SQL
 
06:47
Constraint In Oracle PL SQL oracle tutorial for beginners A) UNIQUE CONSTRAINT : A unique constraint is uniquely defines a record. Its value is not repeated. It can be null. B)NOT NULL CONSTRAINT: Not null constraint restrict from inserting null values. If we want some columns does not take null values then we can use this constraint. C)CHECK CONSTRAINT: A check constraint allows you to specify a condition on particular column in a table. we can add our custom logical conditions. CREATE TABLE TEST2 ( ID VARCHAR2(10) UNIQUE, NAME VARCHAR2(50), DEPT VARCHAR2(10) NOT NULL, AGE NUMBER(10), CHECK (AGE BETWEEN 18 and 60) ); #techquerypond https://techquerypond.wordpress.com https://techquerypond.com https://twitter.com/techquerypond
Views: 194 Tech Query Pond
SQL CASE
 
05:44
Jamie King of Neumont University demonstrating CASE.
Views: 31949 Jamie King
PL/SQL Tutorial | COALESCE Function in Oracle Database
 
05:31
Learn fetching all non-null expression using oracle Coalesce function with example. If all expressions evaluate to null, then the COALESCE function will return null. Coalesce function in Oracle, What is coalesce function, When to use coalesce function, How to use coalesce function in oracle, How to fetch non-null values in oracle using coalesce, Linkedin: https://www.linkedin.com/in/aditya-kumar-roy-b3673368/ Facebook: https://www.facebook.com/SpecializeAutomation/
Oracle SQL Tutorial 15 - How to Add Primary Key Constraints
 
02:54
The goal of this video is to take the CREATE TABLE statement we have and walk through the different ways to create primary keys. This and foreign keys are the most common constraints, so we need to make sure that you have this one down. Once we have a more complex database design with multiple tables, we will learn the proper way to create foreign keys. For now, I am going to keep all of our constraints at the column level, unnamed. The only exception is the primary key, because that is what we are focusing on in this video. The first way to create the primary key is at the column level, unnamed. The primary key is very important because it what we use to distinguish rows from one another. Every table you create is going to need a primary key, and I suggest putting a lot of effort into making sure your keys are set up correctly and organized. --Delete the table if needed: DROP TABLE users; CREATE TABLE users( user_id NUMBER PRIMARY KEY, username VARCHAR2(50 CHAR) NOT NULL UNIQUE ) The next way is at the column level, but named: --Delete the table: DROP TABLE users; CREATE TABLE users( user_id NUMBER CONSTRAINT users_pk PRIMARY KEY, username VARCHAR2(50 CHAR)NOT NULL UNIQUE ) The general naming convention here is the table name followed by an underscore, followed by pk for primary key. Finally, the third way, which is at the table level, is the way we are going to create our primary key: --Delete the table: DROP TABLE users; CREATE TABLE users( user_id NUMBER, username VARCHAR2(50 CHAR) NOT NULL UNIQUE, CONSTRAINT users_pk PRIMARY KEY (user_id) ) Now, once you've created these constraints, you can use Oracle SQL Developer to find these constraints. Open your databases in the connections tab and find the table in the Tables folder. Double click your table and travel to the Constraints tab. You can tell here that the UNIQUE constraint still exists in this table, but it has a pretty disgusting name. It kind of wants to make me puke. Referencing that constraint in the future with that wacky name would be a burden. Engrave these three options in your head so that you can use any of them whenever you need and can read other peoples' code. Thank you for sticking with the series thus far. In the next video, we will be…doing something. See you then! :) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Support me on Patreon! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 16140 Caleb Curry
Null Comparisons in SQL Where Clause - SQL LESSON 26
 
05:34
Null Comparisons in SQL Where Clause - SQL LESSON 26
Views: 7644 HandsonERP
7. Compile-time warnings help avoid "WHEN OTHERS THEN NULL".
 
03:23
One of Tom Kyte's favorite pet peeves, the following exception sections "swallow up" errors. EXCEPTION WHEN OTHERS THEN NULL; EXCEPTION WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE (SQLERRM); In fact, any exception handler that does not re-raise the same exception or another, runs the risk of hiding errors from the calling subprogram, your users, and yourself as you debug your code. Generally, you should log the error, then re-raise it. There are certainly some cases in which this advice does not hold (for example: a function that fetches a single row for a primary key. If there is no row for the key, it's not an application error, so just return NULL). In those cases, include a comment so that the person maintaining your code in the distant future knows that you weren't simply ignoring the Wisdom of the Kyte. Example: EXCEPTION WHEN OTHERS THEN /* No company or this ID, let calling subprogram decide what to do */ RETURN NULL; One way to avoid this problem is to turn on compile-time warnings. Then when your program unit is compiled, you will be warned if the compiler has identified an exception handler that does not contain a RAISE statement or a call to RAISE_APPLICATION_ERROR. Related blog post: http://stevenfeuersteinonplsql.blogspot.com/2016/03/nine-good-to-knows-about-plsql-error.html ======================================== Practically Perfect PL/SQL with Steven Feuerstein Copyright © 2015 Oracle and/or its affiliates. Oracle is a registered trademark of Oracle and/or its affiliates. All rights reserved. Other names may be registered trademarks of their respective owners. Oracle disclaims any warranties or representations as to the accuracy or completeness of this recording, demonstration, and/or written materials (the “Materials”). The Materials are provided “as is” without any warranty of any kind, either express or implied, including without limitation warranties or merchantability, fitness for a particular purpose, and non-infringement.
CASE Statement in Sql Server to Handle NULL Explained in Hindi
 
05:25
CASE Statement in Sql Server to Handle NULL Explained in Hindi SQL Server: CASE WHEN OR THEN ELSE END
Views: 48 Hindi Life
9-Oracle Database - SQL - select conditions between in is null logical operators and or not.avi
 
21:15
Oracle Database - SQL - select where compasion operators conditions between in is null logical operators and or not
Views: 1342 Adel Sabour
SQL 018 SELECT WHERE IS NULL or How can I find unknown values?
 
02:12
Explains the SELECT WHERE IS NULL clause. From http://ComputerBasedTrainingInc.com SQL Course. Learn by doing SQL commands for ANSI Standard SQL, Access, DB2, MySQL, Oracle, PostgreSQL, and SQL Server.
Views: 987 cbtinc
Oracle username and password and Account unlocking
 
08:37
all education purpose videos
Views: 283131 Chandra Shekhar Reddy
PL/SQL: Coalesce Function
 
04:36
In this tutorial, you'll learn how to make use of coalesce function in oracle SQL. PL/SQL (Procedural Language/Structured Query Language) is Oracle Corporation's procedural extension for SQL and the Oracle relational database. PL/SQL is available in Oracle Database (since version 7), TimesTen in-memory database (since version 11.2.1), and IBM DB2 (since version 9.7).[1] Oracle Corporation usually extends PL/SQL functionality with each successive release of the Oracle Database. PL/SQL includes procedural language elements such as conditions and loops. It allows declaration of constants and variables, procedures and functions, types and variables of those types, and triggers. It can handle exceptions (runtime errors). Arrays are supported involving the use of PL/SQL collections. Implementations from version 8 of Oracle Database onwards have included features associated with object-orientation. One can create PL/SQL units such as procedures, functions, packages, types, and triggers, which are stored in the database for reuse by applications that use any of the Oracle Database programmatic interfaces. PL/SQL works analogously to the embedded procedural languages associated with other relational databases. For example, Sybase ASE and Microsoft SQL Server have Transact-SQL, PostgreSQL has PL/pgSQL (which emulates PL/SQL to an extent), and IBM DB2 includes SQL Procedural Language,[2] which conforms to the ISO SQL’s SQL/PSM standard. The designers of PL/SQL modeled its syntax on that of Ada. Both Ada and PL/SQL have Pascal as a common ancestor, and so PL/SQL also resembles Pascal in several aspects. However, the structure of a PL/SQL package does not resemble the basic Object Pascal program structure as implemented by a Borland Delphi or Free Pascal unit. Programmers can define public and private global data-types, constants and static variables in a PL/SQL package.[3] PL/SQL also allows for the definition of classes and instantiating these as objects in PL/SQL code. This resembles usage in object-oriented programming languages like Object Pascal, C++ and Java. PL/SQL refers to a class as an "Abstract Data Type" (ADT) or "User Defined Type" (UDT), and defines it as an Oracle SQL data-type as opposed to a PL/SQL user-defined type, allowing its use in both the Oracle SQL Engine and the Oracle PL/SQL engine. The constructor and methods of an Abstract Data Type are written in PL/SQL. The resulting Abstract Data Type can operate as an object class in PL/SQL. Such objects can also persist as column values in Oracle database tables. PL/SQL is fundamentally distinct from Transact-SQL, despite superficial similarities. Porting code from one to the other usually involves non-trivial work, not only due to the differences in the feature sets of the two languages,[4] but also due to the very significant differences in the way Oracle and SQL Server deal with concurrency and locking. There are software tools available that claim to facilitate porting including Oracle Translation Scratch Editor,[5] CEITON MSSQL/Oracle Compiler [6] and SwisSQL.[7] The StepSqlite product is a PL/SQL compiler for the popular small database SQLite. PL/SQL Program Unit A PL/SQL program unit is one of the following: PL/SQL anonymous block, procedure, function, package specification, package body, trigger, type specification, type body, library. Program units are the PL/SQL source code that is compiled, developed and ultimately executed on the database. The basic unit of a PL/SQL source program is the block, which groups together related declarations and statements. A PL/SQL block is defined by the keywords DECLARE, BEGIN, EXCEPTION, and END. These keywords divide the block into a declarative part, an executable part, and an exception-handling part. The declaration section is optional and may be used to define and initialize constants and variables. If a variable is not initialized then it defaults to NULL value. The optional exception-handling part is used to handle run time errors. Only the executable part is required. A block can have a label. Package Packages are groups of conceptually linked functions, procedures, variables, PL/SQL table and record TYPE statements, constants, cursors etc. The use of packages promotes re-use of code. Packages are composed of the package specification and an optional package body. The specification is the interface to the application; it declares the types, variables, constants, exceptions, cursors, and subprograms available. The body fully defines cursors and subprograms, and so implements the specification. Two advantages of packages are: Modular approach, encapsulation/hiding of business logic, security, performance improvement, re-usability. They support object-oriented programming features like function overloading and encapsulation. Using package variables one can declare session level (scoped) variables, since variables declared in the package specification have a session scope.
Views: 3113 radhikaravikumar
Grouping Sets in SQL Server
 
09:36
grouping sets examples in sql server sql server grouping sets order by grouping sql server 2008 grouping sets example sql server group by union all Grouping sets is a new feature introduced in SQL Server 2008. Let us understand Grouping sets with an example. We want to calculate Sum of Salary by Country and Gender. We can very easily achieve this using a Group By query as shown below Select Country, Gender, Sum(Salary) as TotalSalary From Employees Group By Country, Gender Within the same result set we also want Sum of Salary just by Country. To achieve the above result we could combine 2 Group By queries using UNION ALL as shown below. Select Country, Gender, Sum(Salary) as TotalSalary From Employees Group By Country, Gender UNION ALL Select Country, NULL, Sum(Salary) as TotalSalary From Employees Group By Country Within the same result set we also want Sum of Salary just by Gender. We can achieve this by combining 3 Group By queries using UNION ALL as shown below Select Country, Gender, Sum(Salary) as TotalSalary From Employees Group By Country, Gender UNION ALL Select Country, NULL, Sum(Salary) as TotalSalary From Employees Group By Country UNION ALL Select NULL, Gender, Sum(Salary) as TotalSalary From Employees Group By Gender Finally we also want the grand total of Salary. In this case we are not grouping on any particular column. So both Country and Gender columns will be NULL in the resultset. To achieve this we will have to combine the fourth query using UNION ALL as shown below. Select Country, Gender, Sum(Salary) as TotalSalary From Employees Group By Country, Gender UNION ALL Select Country, NULL, Sum(Salary) as TotalSalary From Employees Group By Country UNION ALL Select NULL, Gender, Sum(Salary) as TotalSalary From Employees Group By Gender UNION ALL Select NULL, NULL, Sum(Salary) as TotalSalary From Employees There are 2 problems with the above approach. The query is huge as we have combined different Group By queries using UNION ALL operator. This can grow even more if we start to add more groups The Employees table has to be accessed 4 times, once for every query. If we use Grouping Sets feature introduced in SQL Server 2008, the amount of T-SQL code that you have to write will be greatly reduced. The following Grouping Sets query produce the same result as the above UNION ALL query. Select Country, Gender, Sum(Salary) TotalSalary From Employees Group BY GROUPING SETS ( (Country, Gender), -- Sum of Salary by Country and Gender (Country), -- Sum of Salary by Country (Gender) , -- Sum of Salary by Gender () -- Grand Total ) The order of the rows in the result set is not the same as in the case of UNION ALL query. To control the order use order by as shown below. Select Country, Gender, Sum(Salary) TotalSalary From Employees Group BY GROUPING SETS ( (Country, Gender), -- Sum of Salary by Country and Gender (Country), -- Sum of Salary by Country (Gender) , -- Sum of Salary by Gender () -- Grand Total ) Order By Grouping(Country), Grouping(Gender), Gender Text version of the video http://csharp-video-tutorials.blogspot.com/2015/09/grouping-sets-in-sql-server.html Slides http://csharp-video-tutorials.blogspot.com/2015/09/grouping-sets-in-sql-server_19.html All SQL Server Text Articles http://csharp-video-tutorials.blogspot.com/p/free-sql-server-video-tutorials-for.html All SQL Server Slides http://csharp-video-tutorials.blogspot.com/p/sql-server.html All Dot Net and SQL Server Tutorials in English https://www.youtube.com/user/kudvenkat/playlists?view=1&sort=dd All Dot Net and SQL Server Tutorials in Arabic https://www.youtube.com/c/KudvenkatArabic/playlists
Views: 50254 kudvenkat
Oracle SQL Tutorial 6 - Relationships and Primary and Foreign Keys - Database Design Primer 3
 
29:40
HAPPY VALENTINES DAY!!! Let's talk relationships.. This is the 6th video in your Oracle Database series. We are discussing database relationships which are a key feature of relational database management systems. We first discussed entities and attributes. I talked about how each entity is assigned a table and each attribute is a column within a table. We moved on to the three kinds of relationships. The first was one-to-one. This describes an entity and an attribute. A piece of data that is exclusive to an entity is, by definition, an attribute of that entity. This is stored in one table with the attribute being a column within this table. The second relationship is one-to-many. This relationship is between two entities. The way we properly store this in a database is using a foreign key in the child table. Remember, the child table is the entity on the many side of the one-to-many relationship. Every row within the child table will have a value for the foreign key that references a primary key in the parent table. This assumes that the foreign key field is not optional (NOT NULL). If the foreign key is optional, than a reference is not required but any reference must be valid. The third kind of relationship is a many-to-many relationship. In this situation, we need 3 tables. The many-to-many relationship is broken up into two one-to-many relationships. The intermediary table will associate each entity from one table with the appropriate entities in the other table. There is debate as to whether this table needs a primary key. This is because you can intact use the combination of two foreign keys as a primary key. This works because we will never have two duplicate rows within the intermediary table and the two foreign keys work as a compound key because of this. We finally discussed primary keys and foreign keys. Primary keys are used to keep each row inside of a table unique. If this key is a computer generated number it is known as a surrogate key, otherwise it is known as a natural key. Natural keys have real world meaning. For example, a social security number may work, or an email address (in some situations), etc. Whichever type of key you choose is solely up to you and/or the company you may be working for. HELP ME! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://Twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 47191 Caleb Curry