函数运算符
最近更新时间: 2024-10-17 17:10:00
分布式实例支持以下7种类型的函数：
流程控制函数（Control Flow Functions）
字符串函数（String Functions）
数字函数（Numeric Functions and Operators）
日期时间函数（Date and Time Functions）
聚合函数（Aggregate (GROUP BY) Functions）
位函数（Bit Functions and Operators）
转换函数（Cast Functions and Operators）
以上类型的各函数具体描述如下：
流程控制函数（Control Flow Functions）
| 函数名 | 描述 |
|---|---|
| CASE | Case operator |
| IF() | If/else construct |
| IFNULL() | Null if/else construct |
| NULLIF() | Return NULL if expr1 = expr2 |
字符串函数（String Functions）
| 函数名 | 描述 |
|---|---|
| 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 |
| LOAD_FILE() | Load the named file |
| 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 |
| MATCH | Perform full-text search |
| 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 |
| SOUNDEX() | Return a soundex string |
| SOUNDS LIKE | Compare sounds |
| 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 |
| TRIM() | Remove leading and trailing spaces |
| UCASE() | Synonym for UPPER() |
| UNHEX() | Return a string containing hex representation of a number |
| UPPER() | Convert to uppercase |
| WEIGHT_STRING() | Return the weight string for a string |
数字函数（Numeric Functions and Operators）
| 函数名 | 描述 |
|---|---|
| ABS() | Return the absolute value |
| ACOS() | Return the arc cosine |
| ASIN() | Return the arc sine |
| ATAN() | Return the arc tangent |
| ATAN2(), ATAN() | Return the arc tangent of the two arguments |
| CEIL() | Return the smallest integer value not less than the argument |
| CEILING() | Return the smallest integer value not less than the argument |
| CONV() | Convert numbers between different number bases |
| COS() | Return the cosine |
| COT() | Return the cotangent |
| CRC32() | Compute a cyclic redundancy check value |
| DEGREES() | Convert radians to degrees |
| DIV | Integer division |
| / | Division operator |
| EXP() | Raise to the power of |
| FLOOR() | Return the largest integer value not greater than the argument |
| LN() | Return the natural logarithm of the argument |
| LOG() | Return the natural logarithm of the first argument |
| LOG10() | Return the base-10 logarithm of the argument |
| LOG2() | Return the base-2 logarithm of the argument |
| - | Minus operator |
| MOD() | Return the remainder |
| %, MOD | Modulo operator |
| PI() | Return the value of pi |
| + | Addition operator |
| POW() | Return the argument raised to the specified power |
| POWER() | Return the argument raised to the specified power |
| RADIANS() | Return argument converted to radians |
| RAND() | Return a random floating-point value |
| ROUND() | Round the argument |
| SIGN() | Return the sign of the argument |
| SIN() | Return the sine of the argument |
| SQRT() | Return the square root of the argument |
| TAN() | Return the tangent of the argument |
| * | Multiplication operator |
| TRUNCATE() | Truncate to specified number of decimal places |
| - | Change the sign of the argument |
日期时间函数（Date and Time Functions）
| 函数名 | 描述 |
|---|---|
| ADDDATE() | Add time values (intervals) to a date value |
| ADDTIME() | Add time |
| CONVERT_TZ() | Convert from one time zone to another |
| CURDATE() | Return the current date |
| CURRENT_DATE(), | CURRENT_DATE Synonyms for CURDATE() |
| CURRENT_TIME(), CURRENT_TIME | Synonyms for CURTIME() |
| CURRENT_TIMESTAMP(), CURRENT_TIMESTAMP | Synonyms for NOW() |
| CURTIME() | Return the current time |
| DATE() | Extract the date part of a date or datetime expression |
| DATE_ADD() | Add time values (intervals) to a date value |
| DATE_FORMAT() | Format date as specified |
| DATE_SUB() | Subtract a time value (interval) from a date |
| DATEDIFF() | Subtract two dates |
| DAY() | Synonym for DAYOFMONTH() |
| DAYNAME() | Return the name of the weekday |
| DAYOFMONTH() | Return the day of the month (0-31) |
| DAYOFWEEK() | Return the weekday index of the argument |
| DAYOFYEAR() | Return the day of the year (1-366) |
| EXTRACT() | Extract part of a date |
| FROM_DAYS() | Convert a day number to a date |
| FROM_UNIXTIME() | Format Unix timestamp as a date |
| GET_FORMAT() | Return a date format string |
| HOUR() | Extract the hour |
| LAST_DAY | Return the last day of the month for the argument |
| LOCALTIME(), LOCALTIME | Synonym for NOW() |
| LOCALTIMESTAMP, LOCALTIMESTAMP() | Synonym for NOW() |
| MAKEDATE() | Create a date from the year and day of year |
| MAKETIME() | Create time from hour, minute, second |
| MICROSECOND() | Return the microseconds from argument |
| MINUTE() | Return the minute from the argument |
| MONTH() | Return the month from the date passed |
| MONTHNAME() | Return the name of the month |
| NOW() | Return the current date and time |
| PERIOD_ADD() | Add a period to a year-month |
| PERIOD_DIFF() | Return the number of months between periods |
| QUARTER() | Return the quarter from a date argument |
| SEC_TO_TIME() | Converts seconds to 'HHimgSS' format |
| SECOND() | Return the second (0-59) |
| STR_TO_DATE() | Convert a string to a date |
| SUBDATE() | Synonym for DATE_SUB() when invoked with three arguments |
| SUBTIME() | Subtract times |
| SYSDATE() | Return the time at which the function executes |
| TIME() | Extract the time portion of the expression passed |
| TIME_FORMAT() | Format as time |
| TIME_TO_SEC() | Return the argument converted to seconds |
| TIMEDIFF() | Subtract time |
| TIMESTAMP() | With a single argument, this function returns the date or datetime expression; with two arguments, the sum of the arguments |
| TIMESTAMPADD() | Add an interval to a datetime expression |
| TIMESTAMPDIFF() | Subtract an interval from a datetime expression |
| TO_DAYS() | Return the date argument converted to days |
| TO_SECONDS() | Return the date or datetime argument converted to seconds since Year 0 |
| UNIX_TIMESTAMP() | Return a Unix timestamp |
| UTC_DATE() | Return the current UTC date |
| UTC_TIME() | Return the current UTC time |
| UTC_TIMESTAMP() | Return the current UTC date and time |
| WEEK() | Return the week number |
| WEEKDAY() | Return the weekday index |
| WEEKOFYEAR() | Return the calendar week of the date (1-53) |
| YEAR() | Return the year |
| YEARWEEK() | Return the year and week |
聚合函数（Aggregate (GROUP BY) Functions）
| 函数名 | 描述 |
|---|---|
| AVG() | Return the average value of the argument |
| COUNT() | Return a count of the number of rows returned |
| MAX() | Return the maximum value |
| MIN() | Return the minimum value |
| SUM() | Return the sum |
位函数（Bit Functions and Operators）
| 函数名 | 描述 |
|---|---|
| BIT_COUNT() | Return the number of bits that are set |
| & | Bitwise AND |
| ~ | Bitwise inversion |
| | | Bitwise OR |
| ^ | Bitwise XOR |
| << | Left shift |
| >> | Right shift |
转换函数（Cast Functions and Operators）
| 函数名 | 描述 |
|---|---|
| BINARY | Cast a string to a binary string |
| CAST() | Cast a value as a certain type |
| CONVERT() | Cast a value as a certain type |