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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 n...

Returns the starting position of first occurrence of pattern in a specified  expression . Syntax: Select Patindex(pattern char,expression char) returns int Note: It returns the integer value. It returns the zero (0) when you are specified position is not matched in the expression. Here is the simple string with postions for using entire examples in the Patindex Function. 1 2 3 4 5 6 7 8 9 10 11 12 L E A D F I R S T S Q L Example-1: SELECT PATINDEX ( '%a%' , 'LEADFIRSTSQL' ) [PATINDEX_POSITION] Example-2: SELECT PATINDEX ( '%S%' , 'LEADFIRSTSQL' ) [PATINDEX_POSITION] Example-3: SELECT PATINDEX ( '%_R_%' , 'LEADFIRSTSQL' ) [PATINDEX_POSITION] Example-4: SELECT PATINDEX ( '%[abcde]%' , 'LEADFIRSTSQL' ) [PATINDEX_POSITION] Here is the example any of the character ...