Question

name     amount       date    
x        200       2016-08-11 07:00:00
x        111       2016-08-03 19:32:34
y        10        2016-07-19 07:00:00
y        9         2016-07-20 09:30:00

我想为每个用户获得最后一天的付费金额，我想要这样的输出

 name     amount       date    
    x        200       2016-08-11 07:00:00
    y        9         2016-07-20 09:30:00

如何查找每个用户的最后更新数据组

Answer 1

只需尝试这个

$sql = "SELECT * FROM table_name ORDER BY `date` DESC GROUP BY `name`";
$query = $this->db->query($sql);
$result = $query->result_array();

print_r($result);

Answer 2

使用MAX我们可以实现这个目标

DECLARE @Table1 TABLE 
    ( name  varchar(1),  amount  int,  date  varchar(19))
;

INSERT INTO @Table1
    ( name ,  amount ,  date )
VALUES
    ('x', 200, '2016-08-11 07:00:00'),
    ('x', 111, '2016-08-03 19:32:34'),
    ('y', 10, '2016-07-19 07:00:00'),
    ('y', 9, '2016-07-20 09:30:00')
;

脚本

select T.name ,  T.amount,TT.Dt as Dates  from @Table1 T

INNER JOIN (select name,MAX(date)Dt from @Table1
GROUP BY Name)TT
ON T.name = TT.name AND T.date = TT.Dt
ORDER BY T.name

如何使用codeigniter查询获取上次更新的金额

2 个答案: