从 MySQL 组中的时间戳获取第一个日期，并按具有重复值的另一列分组
mysqlmysqli database更新于 2024/1/9 17:47:00
为此，您可以使用聚合函数 MIN() 和 GROUP BY。让我们首先创建一个表−
mysql> create table DemoTable1870 ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Value int, ShippingTimestamp varchar(100) ); Query OK, 0 rows affected (0.00 sec)
使用 insert 命令在表中插入一些记录 −
mysql> insert into DemoTable1870(Value,ShippingTimestamp) values(10,'1570645800'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1870(Value,ShippingTimestamp) values(10,'1546194600'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1870(Value,ShippingTimestamp) values(11,'1573324200'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1870(Value,ShippingTimestamp) values(11,'1557599400'); Query OK, 1 row affected (0.00 sec)
使用 select 语句显示表中的所有记录 −
mysql> select * from DemoTable1870;
这将产生以下输出 −
+----+-------+-------------------+ | Id | Value | ShippingTimestamp | +----+-------+-------------------+ | 1 | 10 | 1570645800 | | 2 | 10 | 1546194600 | | 3 | 11 | 1573324200 | | 4 | 11 | 1557599400 | +----+-------+-------------------+ 4 rows in set (0.00 sec)
这是在 MySQL 中从时间戳获取第一个日期的查询 &Minus;
mysql> select min(ShippingTimestamp) from DemoTable1870 group by Value;
这将产生以下输出 −
+------------------------+ | min(ShippingTimestamp) | +------------------------+ | 1546194600 | | 1557599400 | +------------------------+ 2 rows in set (0.00 sec)
