If str contains an illegal date, time, or datetime value, STR_TO_DATE() returns NULL. An illegal value also produces a warning. Under specific SQL_MODE settings an error may also be generated if the str isn't a valid date: ALLOW_INVALID_DATES NO_ZERO_DATE NO_ZERO_IN_DATE The ...
3. MySQL Str to Date (字符串转换为日期)函数:str_to_date(str, format) select str_to_date('08/09/2008', '%m/%d/%Y'); -- 2008-08-09 select str_to_date('08/09/08' , '%m/%d/%y'); -- 2008-08-09 select str_to_date('08.09.2008', '%m.%d.%Y'); -- 2008-08-09 select ...
DATE_ADD / DATE_SUB / PERIOD_ADD TIME_TO_SEC / SEC_TO_TIME 2.7 比较日期和时间 DATEDIFF / TIMEDIFF 2.8 从1970 1 1-今的秒数 unix_timestamp 3. 聚合函数和数值函数 3.1 聚合函数 3.1.1 计数 COUNT 3.1.2 对一组数据进行运算 SUM AVG MAX MIN 3.1.3 拼接同组的值 GROUP_CONCAT 3.2 数值函数...
CREATE FUNCTION `to_date`(datevalue VARCHAR(100), formatvalue VARCHAR(100) ) RETURNS datetime BEGIN IF UPPER(formatvalue) = 'YYYYMM' THEN RETURN STR_TO_DATE(CONCAT(datevalue,'01'),'%Y%m%d'); ELSEIF UPPER(formatvalue) = 'YYYY-MM' THEN RETURN STR_TO_DATE(CONCAT(datevalue,'-01'),'%Y...
Returns year quarter from 1 to 4. SECOND Returns the second of a time. SEC_TO_TIME Converts a second to a time. 4 STR_TO_DATE Converts a string to date. SUBDATE Subtract a date unit or number of days. SUBTIME Subtracts a time from a date/time. ...
EXTRACT (interval_name FROM date)//从date中提取日期的指定部分MAKEDATE(year,day)//给出年及年中的第几天,生成日期串MAKETIME(hour,minute,second)//生成时间串MONTHNAME(date)//英文月份名SEC_TO_TIME(seconds)//秒数转成时间STR_TO_DATE(string,format)//字串转成时间,以format格式显示TIMEDIFF(datetime1...
str_to_datetime_457.result strict.result strict_autoinc_1myisam.result strict_autoinc_2innodb.result strict_autoinc_3heap.result subselect-crash_15755.result subselect.result subselect2.result subselect3.result subselect3_jcl6.result subselect4.result subselect_cache.result subselect_d...
str_to_datetime_457.result strict.result strict_autoinc_1myisam.result strict_autoinc_2innodb.result strict_autoinc_3heap.result subselect.result subselect2.result subselect3.result subselect3_jcl6.result subselect4.result subselect_cache.result subselect_debug.result subselect_exists2in.result...
说明:假如expr1 不为NULL,则 IFNULL() 的返回值为expr1; 否则其返回值为 expr2。IFNULL()的返回值是数字或是字符串,具体情况取决于其所使用的语境。 注意:默认结果值为两个表达式中更加“通用”的一个,顺序为STRING、 REAL或 INTEGER。 例子:
3600+分钟*60+秒值SEC_TO_TIME(TIME)--相反--日期加操作DATE_ADD(date,INTERVAL expr unit)--ADDDATE('2010-12-31 23:59:59', INTERVAL '1:1' MINUTE_SECOND)ADDDATE(date,INTERVAL expr unit) ADDTIME(expr1,expr2)--日期减操作SUBDATE(date,INTERVAL expr unit)...