透過在 MySQL 中對日期進行分組來顯示記錄
要對 MySQL 中的日期進行分組,請使用 GROUP BY 子句 −
mysql> create table DemoTable2002 ( CustomerName varchar(20), CustomerShippingDate datetime ); Query OK, 0 rows affected (0.61 sec)
使用插入命令在表中插入一些記錄 −
mysql> insert into DemoTable2002 values('Chris','2019-01-10'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable2002 values('David','2018-12-31'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable2002 values('David','2019-12-16'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable2002 values('Chris','2018-12-01'); Query OK, 1 row affected (0.12 sec)
使用 select 語句從表中顯示所有記錄 −
mysql> select * from DemoTable2002;
這將生成以下輸出 −
+--------------+----------------------+ | CustomerName | CustomerShippingDate | +--------------+----------------------+ | Chris | 2019-01-10 00:00:00 | | David | 2018-12-31 00:00:00 | | David | 2019-12-16 00:00:00 | | Chris | 2018-12-01 00:00:00 | +--------------+----------------------+ 4 rows in set (0.00 sec)
以下是透過對日期進行分組來顯示記錄的查詢 −
mysql> select date(min(CustomerShippingDate)),date(max(CustomerShippingDate)),CustomerName from DemoTable2002 group by CustomerName;
這將生成以下輸出 −
+---------------------------------+---------------------------------+--------------+ | date(min(CustomerShippingDate)) | date(max(CustomerShippingDate)) | CustomerName | +---------------------------------+---------------------------------+--------------+ | 2018-12-01 | 2019-01-10 | Chris | | 2018-12-31 | 2019-12-16 | David | +---------------------------------+---------------------------------+--------------+ 2 rows in set (0.00 sec)
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