Question

我正在使用XAMPP MYSQL

我有表，Date列是字符串

  Date    |  Customer   |   Location   | Cash | Balance |
2015/6/23    LBalance      California    5000    3000
2015/6/25    LBalance      New York      6000    4500
2015/6/25    InHoss Dept.  South Beach   15000   1000
2015/6/20    InHoss Dept.  South Beach   15000   1000
2015/6/17    InHoss Dept.  South Beach   15000   1000
2015/6/22    LBalance      California    5000    4000
2015/6/22    LBalance      New York      6000    6000
2015/6/17    InHoss Dept.  North Beach   18000   1000

如何选择查询具有不同位置的每个客户的最新日期记录？

期待结果：

Date      |  Customer   |    Location   | Cash | Balance |
2015/6/23    LBalance      California    5000    3000
2015/6/25    LBalance      New York      6000    4500
2015/6/25    InHoss Dept.  South Beach   15000   1000
2015/6/17    InHoss Dept.  North Beach   18000   1000

这是我最接近的：选择客户，位置，现金，余额，最大（日期）AS＆＃34; As Of＆＃34;来自mytable WHERE Customer =＆＃39; LBalance＆＃39; GROUP BY客户，位置。虽然它显示了客户的最新日期，但另一列只显示了他们的第一个结果。

Answer 1

从xampp中选择（*）其中date =（从xampp中选择max（date））

Answer 2

试试吧

with cte (date, Customer, Location, Cash , Balance) as
(
select cast('2015/6/23' as datetime) date, 'LBalance' Customer, 'California' Location, 5000 Cash , 3000 Balance
union all
select cast('2015/6/25' as datetime) date, 'LBalance' Customer, 'New York' Location, 6000 Cash , 4500 Balance
union all
select cast('2015/6/25' as datetime) date, 'InHoss Dept.' Customer, 'South Beach' Location, 15000 Cash , 1000 Balance
union all
select cast('2015/6/20' as datetime) date, 'InHoss Dept.' Customer, 'South Beach' Location, 15000 Cash , 1000 Balance
union all
select cast('2015/6/17' as datetime) date, 'InHoss Dept.' Customer, 'South Beach' Location, 15000 Cash , 1000 Balance
union all
select cast('2015/6/22' as datetime) date, 'LBalance' Customer, 'California' Location, 5000 Cash , 4000 Balance
union all
select cast('2015/6/22' as datetime) date, 'LBalance' Customer, 'New York' Location, 6000 Cash , 6000 Balance
union all
select cast('2015/6/27' as datetime) date, 'InHoss Dept.' Customer, 'North Beach' Location, 18000 Cash , 1000 Balance
)

select m.Date, m.Customer, m.Location, m.Cash, m.Balance 
   from cte m
   where m.Date = (select max(mm.Date) 
                     from cte mm 
                    where mm.customer=m.customer
                      and mm.location = m.location )

我已经检查过我的例子，确实你正在使用mysql示例

Answer 3

获取最新记录，您使用max（）函数，就像您使用group by的每个客户和位置一样检查一下：

 public Button btn2;
public void onClick(){
    btn2=(Button)findViewById(R.id.btn2);
    btn2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(MainActivity.this,submit.class);
            startActivity(intent);
        }
    });

}

修改。如果日期是varchar（逻辑错误），你可以在下面做。

select max(date) , CUSTOMER, LOCATION from table GROUP BY CUSTOMER , LOCATION

Answer 4

因为，你想要一个日期到字符串转换。不确定这是否需要，因为，如果没有转换，max（date）可能仍然有用。

select max(STR_TO_DATE(Date, '%Y/%m/%d')),Customer, location, cash,balance from YourTable group by Customer, Location

快乐编码..请确认您的需求。变得难以跟踪编辑。

Answer 5

也许你可以试试这个

select a.*
from yourtable a JOIN
( select Customer,Location,Max(Date) as Mdate
   from yourtable
   group by Customer,Location) b
on a.Customer=b.Customer and a.Location=b.Location and a.Date=b.Mdate

如何选择最新的日期记录并在mysql中显示其他列？

5 个答案: