日期时间函数
更新时间：2024-02-23
本文介绍了 GaiaDB-X 支持的日期时间函数。
| 函数名 | 描述 |
|---|---|
| ADDDATE() | Add time values (intervals) to a date value |
| ADDTIME() | Add time |
| 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 |
| HOUR() | Extract the hour |
| LAST_DAY | Return the last day of the month for the argument |
| 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 'hh:mm:ss' 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 |
相比MySQL 5.7，GaiaDB-X暂不支持的函数，如下：
| 函数名 | 描述 |
|---|---|
| CONVERT_TZ() | Convert from one time zone to another |
| GET_FORMAT() | Return a date format string |
| LOCALTIME(), LOCALTIME | Synonym for NOW() |
| LOCALTIMESTAMP, LOCALTIMESTAMP() | Synonym for NOW() |