SQL Server String Functions (Full List)

Transact-SQL (T-SQL) includes a number of scalar functions that allow us to perform operation on strings when working with SQL Server. These functions accept an input string, and return either a string or a numeric value.

The following is a list of T-SQL string functions available in SQL Server. Click on each function or operator name to see an explanation of the function, its syntax, and examples.

`ASCII()`	Returns the ASCII code value of the leftmost character of a character expression.
`CHAR()`	Converts an int ASCII code to a character value and returns the result.
`CHARINDEX()`	Searches for one character expression inside a second character expression, returning the starting position of the first expression if found.
`CONCAT()`	Returns a string resulting from the concatenation, or joining, of two or more string values in an end-to-end manner.
`CONCAT_WS()`	Returns a string resulting from the concatenation, or joining, of two or more string values in an end-to-end manner, and separating those concatenated string values with the delimiter specified in the first function argument.
`DIFFERENCE()`	Returns an integer value measuring the difference between the `SOUNDEX()` values of two different character expressions.
`FORMAT()`	Returns a value formatted with the specified format and optional culture.
`LEFT()`	Returns the left part of a character string with the specified number of characters.
`LEN()`	Returns the number of characters of the specified string expression, excluding trailing blanks.
`LOWER()`	Returns a character expression after converting uppercase character data to lowercase.
`LTRIM()`	Returns a character expression after it removes leading blanks.
`NCHAR()`	Returns the Unicode character based on the specified integer code.
`PATINDEX()`	Returns the starting position of the first occurrence of a pattern in a specified expression.
`QUOTENAME()`	Returns a Unicode string with the delimiters added to make the input string a valid SQL Server delimited identifier.
`REPLACE()`	Replaces all instances of a given string with another string.
`REPLICATE()`	Repeats a string value a specified number of times, and returns the result.
`REVERSE()`	Returns a string value in reverse order.
`RIGHT()`	Returns the right part of a character string with the specified number of characters.
`RTRIM()`	Removes trailing blanks from a given string.
`SOUNDEX()`	Returns a four-character (SOUNDEX) code to evaluate the similarity of two strings.
`SPACE()`	Returns a string of repeated spaces.
`STR()`	Returns character data converted from numeric data.
`STRING_AGG()`	Concatenates the values of string expressions and places separator values between them.
`STRING_ESCAPE()`	Escapes special characters in texts and returns text with escaped characters.
`STRING_SPLIT()`	Splits a string into rows of substrings, based on a specified separator character.
`STUFF()`	Inserts a string into another string.
`SUBSTRING()`	Returns part of a character, binary, text, or image expression.
`TRANSLATE()`	Returns the string provided as a first argument after some characters specified in the second argument are translated into a destination set of characters specified in the third argument.
`TRIM()`	Removes the space character `char(32)` or other specified characters from the start or end of a string.
`UNICODE()`	Returns the Unicode value of a given character.
`UPPER()`	Returns a character expression with lowercase character data converted to uppercase.

If the input string passed to a string function is not a string value, it is implicitly converted to a text data type.

Also, all built-in string functions except FORMAT are deterministic. This means they return the same value any time they are called with a specific set of input values.