本文介绍了PolarDB-X 1.0支持及不支持的日期时间函数。
支持函数
PolarDB-X 1.0支持如下日期时间函数:
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 |
不支持函数
与MySQL5.7相比,PolarDB-X 1.0暂不支持如下函数:
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() |
另外,暂不支持不带参数的UNIX_TIMESTAMP()
函数,可用UNIX_TIMESTAMP(NOW())
替换。