The following SQL Server string functions process on an input string and return a string or numeric value:
| Function | Description |
|---|---|
| ASCII | Return the ASCII code value of a character |
| CHAR | Convert an ASCII value to a character |
| CHARINDEX | Search for a substring inside a string starting from a specified location and return the position of the substring. |
| CONCAT | Join two or more strings into one string |
| CONCAT_WS | Concatenate multiple strings with a separator into a single string |
| DIFFERENCE | Compare the SOUNDEX() values of two strings |
| FORMAT | Return a value formatted with the specified format and optional culture |
| LEFT | Extract a given a number of characters from a character string starting from the left |
| LEN | Return a number of characters of a character string |
| LOWER | Convert a string to lowercase |
| LTRIM | Return a new string from a specified string after removing all leading blanks |
| NCHAR | Return the Unicode character with the specified integer code, as defined by the Unicode standard |
| PATINDEX | Returns the starting position of the first occurrence of a pattern in a string. |
| QUOTENAME | Returns a Unicode string with the delimiters added to make the input string a valid delimited identifier |
| REPLACE | Replace all occurrences of a substring, within a string, with another substring |
| REPLICATE | Return a string repeated a specified number of times |
| REVERSE | Return the reverse order of a character string |
| RIGHT | Extract a given a number of characters from a character string starting from the right |
| RTRIM | Return a new string from a specified string after removing all trailing blanks |
| SOUNDEX | Return a four-character (SOUNDEX) code of a string based on how it is spoken |
| SPACE | Returns a string of repeated spaces. |
| STR | Returns character data converted from numeric data. |
| STRING_AGG | Concatenate rows of strings with a specified separator into a new string |
| STRING_ESCAPE | Escapes special characters in a string and returns a new string with escaped characters |
| STRING_SPLIT | A table-valued function that splits a string into rows of substrings based on a specified separator. |
| STUFF | Delete a part of a string and then insert another substring into the string starting at a specified position. |
| SUBSTRING | Extract a substring within a string starting from a specified location with a specified length |
| TRANSLATE | Replace several single-characters, one-to-one translation in one operation. |
| TRIM | Return a new string from a specified string after removing all leading and trailing blanks |
| UNICODE | Returns the integer value, as defined by the Unicode standard, of a character. |
| UPPER | Convert a string to uppercase |
