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.
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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 ) |