在日期时间栏
答
使用STR_TO_DATE()函数像这样:
SELECT STR_TO_DATE(CONCAT('2017-12','-01'),'%Y-%m-%d');
SELECT STR_TO_DATE(CONCAT(SUBSTRING_INDEX('2017-45', '-', 1),'-01-01'),'%Y-%m-%d')
+ INTERVAL SUBSTRING_INDEX('2017-45', '-', -1) -1 WEEK;
样品
mysql> SELECT STR_TO_DATE(CONCAT('2017-12','-01'),'%Y-%m-%d');
+-------------------------------------------------+
| STR_TO_DATE(CONCAT('2017-12','-01'),'%Y-%m-%d') |
+-------------------------------------------------+
| 2017-12-01 |
+-------------------------------------------------+
1 row in set (0,00 sec)
mysql> SELECT STR_TO_DATE(CONCAT(SUBSTRING_INDEX('2017-45', '-', 1),'-01-01'),'%Y-%m-%d')
-> + INTERVAL SUBSTRING_INDEX('2017-45', '-', -1) -1 WEEK;
+------------------------------------------------------------------------------------------------------------------------------------------------+
| STR_TO_DATE(CONCAT(SUBSTRING_INDEX('2017-45', '-', 1),'-01-01'),'%Y-%m-%d')
+ INTERVAL SUBSTRING_INDEX('2017-45', '-', -1) -1 WEEK |
+------------------------------------------------------------------------------------------------------------------------------------------------+
| 2017-11-05 |
+------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0,01 sec)
mysql>
的可能的复制[如何转换日期时间为varchar(http://*.com/问题/ 74385 /如何转换日期时间到varchar) –
http://*.com/questions/74385/how-to-convert-datetime-to-varchar –
添加一个月的第一天或第一天 本周 – etsa