String Functions
TiDB supports most of the string functions available in MySQL 5.7 and some of the functions available in Oracle 21.
Supported functions
| Name | Description |
|---|---|
ASCII() | Return numeric value of left-most character |
BIN() | Return a string containing binary representation of a number |
BIT_LENGTH() | Return length of argument in bits |
CHAR() | Return the character for each integer passed |
CHAR_LENGTH() | Return number of characters in argument |
CHARACTER_LENGTH() | Synonym for CHAR_LENGTH() |
CONCAT() | Return concatenated string |
CONCAT_WS() | Return concatenate with separator |
ELT() | Return string at index number |
EXPORT_SET() | Return a string such that for every bit set in the value bits, you get an on string and for every unset bit, you get an off string |
FIELD() | Return the index (position) of the first argument in the subsequent arguments |
FIND_IN_SET() | Return the index position of the first argument within the second argument |
FORMAT() | Return a number formatted to specified number of decimal places |
FROM_BASE64() | Decode to a base-64 string and return result |
HEX() | Return a hexadecimal representation of a decimal or string value |
INSERT() | Insert a substring at the specified position up to the specified number of characters |
INSTR() | Return the index of the first occurrence of substring |
LCASE() | Synonym for LOWER() |
LEFT() | Return the leftmost number of characters as specified |
LENGTH() | Return the length of a string in bytes |
LIKE | Simple pattern matching |
LOCATE() | Return the position of the first occurrence of substring |
LOWER() | Return the argument in lowercase |
LPAD() | Return the string argument, left-padded with the specified string |
LTRIM() | Remove leading spaces |
MAKE_SET() | Return a set of comma-separated strings that have the corresponding bit in bits set |
MID() | Return a substring starting from the specified position |
NOT LIKE | Negation of simple pattern matching |
NOT REGEXP | Negation of REGEXP |
OCT() | Return a string containing octal representation of a number |
OCTET_LENGTH() | Synonym for LENGTH() |
ORD() | Return character code for leftmost character of the argument |
POSITION() | Synonym for LOCATE() |
QUOTE() | Escape the argument for use in an SQL statement |
REGEXP | Pattern matching using regular expressions |
REPEAT() | Repeat a string the specified number of times |
REPLACE() | Replace occurrences of a specified string |
REVERSE() | Reverse the characters in a string |
RIGHT() | Return the specified rightmost number of characters |
RLIKE | Synonym for REGEXP |
RPAD() | Append string the specified number of times |
RTRIM() | Remove trailing spaces |
SPACE() | Return a string of the specified number of spaces |
STRCMP() | Compare two strings |
SUBSTR() | Return the substring as specified |
SUBSTRING() | Return the substring as specified |
SUBSTRING_INDEX() | Return a substring from a string before the specified number of occurrences of the delimiter |
TO_BASE64() | Return the argument converted to a base-64 string |
TRANSLATE() | Replace all occurrences of characters by other characters in a string. It does not treat empty strings as NULL as Oracle does. |
TRIM() | Remove leading and trailing spaces |
UCASE() | Synonym for UPPER() |
UNHEX() | Return a string containing hex representation of a number |
UPPER() | Convert to uppercase |
Unsupported functions
LOAD_FILE()MATCH()SOUNDEX()WEIGHT_STRING()