INT dayofweek(DATETIME date)
DAYOFWEEK函数返回日期的工作日索引值,即星期日为1,星期一为2,星期六为7
参数为Date或者Datetime类型或者可以cast为Date或者Datetime类型的数字
MySQL > select dayofweek('2019-06-25');
+----------------------------------+
| dayofweek('2019-06-25 00:00:00') |
+----------------------------------+
| 3 |
+----------------------------------+
MySQL > select dayofweek(cast(20190625 as date));
+-----------------------------------+
| dayofweek(CAST(20190625 AS DATE)) |
+-----------------------------------+
| 3 |
+-----------------------------------+