让我们首先创建一个表-
mysql> create table DemoTable1946 ( ShippingDate date );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable1946 values('2019-12-11'); mysql> insert into DemoTable1946 values('2018-12-11'); mysql> insert into DemoTable1946 values('2017-12-11'); mysql> insert into DemoTable1946 values('2019-04-22'); mysql> insert into DemoTable1946 values('2019-12-11'); mysql> insert into DemoTable1946 values('2015-12-11');
使用select语句显示表中的所有记录-
mysql> select * from DemoTable1946;
这将产生以下输出-
+--------------+ | ShippingDate | +--------------+ | 2019-12-11 | | 2018-12-11 | | 2017-12-11 | | 2019-04-22 | | 2019-12-11 | | 2015-12-11 | +--------------+ 6 rows in set (0.00 sec)
这是计算特定日期的查询-
mysql> select count(*) from DemoTable1946 where date(ShippingDate)='2019-12-11';
这将产生以下输出-
+----------+ | count(*) | +----------+ | 2 | +----------+ 1 row in set (0.00 sec)