如何使用codeigniter查询获取上次更新的金额

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

I want to get last day paid amount for each user,I want an output like this

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

how to find a user's last updated data group by each users

Answer 1

using MAX we can achieve this

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')
;

Script

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