SQL Server String Functions
SQL Server string functions are scalar functions that perform an operation on a string input value and return a string or numeric value. All built-in string functions, except for CHARINDEX and PATINDEX, are deterministic. This means they return the same value any time they are called with a specific set of input values.
Tags: SQL Server String Functions SQL SQL Server  Functions.
SQL Server string functions are scalar functions that perform an operation on a string input value and return a string or numeric value. All built-in string functions, except for CHARINDEX and PATINDEX, are deterministic. This means they return the same value any time they are called with a specific set of input values.
| Function | Description | 
| ASCII | Returns the ASCII code value of the leftmost character of a character expression. 
Syntax: 
ASCII ( character_expression )  | 
| CHAR | Converts an int ASCII code to a character. 
Syntax: 
CHAR ( integer_expression )  | 
| CHARINDEX | Returns the starting position of the specified expression in a character string. 
Syntax: 
CHARINDEX ( expression1 ,expression2 [ , start_location ] )  | 
| DIFFERENCE | Returns an integer value that indicates the difference between the SOUNDEX values of two character expressions. 
Syntax: 
DIFFERENCE ( character_expression , character_expression )  | 
| LEFT | Returns the left part of a character string with the specified number of characters. 
Syntax: 
LEFT ( character_expression , integer_expression )  | 
| LEN | Returns the number of characters, instead of the number of bytes, of the specified string expression, excluding trailing blanks. 
Syntax: 
LEN ( string_expression )  | 
| LOWER | Returns a character expression after converting uppercase character data to lowercase. 
Syntax: 
LOWER ( string_expression )  | 
| LTRIM | Returns a character expression after it removes leading blanks. 
Syntax: 
LTRIM ( string_expression )  | 
| NCHAR | Returns the Unicode character with the specified integer code, as defined by the Unicode standard. 
Syntax: 
NCHAR ( integer_expression )  | 
| PATINDEX | Returns the starting position of the first occurrence of a pattern in a specified expression, or zeros if the pattern is not found, on all valid text and character data types. 
Syntax: 
PATINDEX ( '%pattern%' , expression )  | 
| QUOTENAME | Returns a Unicode string with the delimiters added to make the input string a valid Microsoft SQL Server 2005 delimited identifier. 
Syntax: 
QUOTENAME ( 'character_string' [ , 'quote_character' ] )  | 
| REPLACE | Replaces all occurrences of the second specified string expression in the first string expression with a third expression. 
Syntax: 
REPLACE ( 'string_expression1' , 'string_expression2' , 'string_expression3' )  | 
| REPLICATE | Repeats a character expression for a specified number of times. 
Syntax: 
REPLICATE ( character_expression ,integer_expression )  | 
| REVERSE | Returns the reverse of a character expression. 
Syntax: 
REVERSE ( character_expression )  | 
| RIGHT | Returns the right part of a character string with the specified number of characters. 
Syntax: 
RIGHT ( character_expression , integer_expression )  | 
| RTRIM | Returns a character string after truncating all trailing blanks. 
Syntax: 
RTRIM ( character_expression )  | 
| SOUNDEX | Returns a four-character (SOUNDEX) code to evaluate the similarity of two strings. 
Syntax: 
SOUNDEX ( character_expression )  | 
| SPACE | Returns a string of repeated spaces. 
Syntax: 
SPACE ( integer_expression )  | 
| STR | Returns character data converted from numeric data. 
Syntax: 
STR ( float_expression [ , length [ , ] ] )  | 
| STUFF | Deletes a specified length of characters and inserts another set of characters at a specified starting point. 
Syntax: 
STUFF ( character_expression , start , length ,character_expression )  | 
| SUBSTRING | Returns part of a character, binary, text, or image expression. 
Syntax: 
SUBSTRING ( expression ,start , length )  | 
| UNICODE | Returns the integer value, as defined by the Unicode standard, for the first character of the input expression. 
Syntax: 
UNICODE ( 'ncharacter_expression' )  | 
| UPPER | Returns a character expression with lowercase character data converted to uppercase. 
Syntax: 
UPPER ( character_expression )  | 
