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Using PATINDEX Function when Creating the Table

Normally Varchar , Nvarchar , Char these data types in sql server it allows character data and numeric data also ,but in some cases we don't want allow numeric data in some columns at this time we use patindex function with check constraint at time creating table or altering column in sql server.

Step-1: Creating Student table with patindex function.
CREATE TABLE Student
(
Id INT IDENTITY(1,1) PRIMARY KEY,
StudentName VARCHAR(100) NOT NULL ,
LivingLocation VARCHAR(100) NULL,constraint chk_studentname
Check (PATINDEX('%[0-9]%', StudentName)=0)
)
GO;


Step-2: Insert Some Sample Data.

INSERT INTO Student
SELECT 'Raki','Hyderabad'
GO;

The above query executed successfully.


INSERT INTO Student
SELECT 'Raki123','Hyderabad'
GO;

The above query not executed successfully,because numeric data existed in StudentName 'Raki123'.

Msg 547, Level 16, State 0, Line 1
The INSERT statement conflicted with the CHECK constraint "chk_studentname". The conflict occurred in database "blog", table "dbo.Student", column 'StudentName'.
The statement has been terminated.

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