With Values Using Alter Table

Step-1: Create Table

CREATE TABLE STUDENT

(

ID INT IDENTITY(1,1) PRIMARY KEY,

STUDENTNAME VARCHAR(100) NOT NULL ,

LIVINGLOCATION VARCHAR(100) NULL

)

Step-2: Insert Some Sample Data

INSERT INTO STUDENT(STUDENTNAME,LIVINGLOCATION)

SELECT 'Rakesh','Hyderabad'

UNION ALL

SELECT 'Raju','Delhi'

UNION ALL

SELECT 'Madhu','Hyderabad'

UNION ALL

SELECT 'Naresh',NULL

UNION ALL

SELECT 'Venaktesh','Chennai'

Step-3:

If we need to add DOJ column to Student table with default constraint , But all the Existing rows want to update Default GETDATE() , if WITH VALUES are not used all existing rows DOJ column should be NULL.

ALTER TABLE STUDENT ADD DOJ DATETIME NULL DEFAULT GETDATE() WITH VALUES

Step-4:

SELECT * FROM STUDENT

Comments

Rank Functions in SQL SERVER

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@@SERVERNAME

@@servername returns the name of the server currently running. Syntax: @@SERVERNAME SELECT @@SERVERNAME O/P sys

Difference between LEN and DATALENGTH

LEN: LEN function returns the number of characters in a variable .it also removes the trailing spaces and then then return the length. Example-1: DECLARE @Name VARCHAR ( 20 )= 'rakesh' SELECT LEN ( @Name ) as [len] Output: Example-2: DECLARE @Name VARCHAR ( 20 )= 'rakesh ' SELECT LEN ( @Name ) as [len] Output: When we observe above variable assigned 'rakesh ' string after that added 3 spaces . Len function removes trailing spaces not leading spaces. DATALENGTH : DATALENG function returns the number of bytes occupy in a variable .it also considered the spaces also. Example-1: DECLARE @Name VARCHAR ( 20 )= 'rakesh' SELECT DATALENGTH ( @Name ) as [DataLength] Output: Example-2: DECLARE @Name VARCHAR ( 20 )= ' rakesh ' SELECT DATALENGTH ( @Name ) as [DataLength] Output: In above example before ' r ' and after ...

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