MySql在单行中获取多行

Question

我有以下Mysql程序。

select

case temp.lineItemTypeID when 1 then temp.tt else 0 end case as planTotalAmount,
case temp.lineItemTypeID when 2 then temp.tt else 0 end case as discountTotalAmount

from (

SELECT
    lineItemTypeID,
    sum(lineitemAmount) as tt from tbl_invoicelineitem
    where date(lineItemcreatedDate) IS NOT NULL
    group by lineItemTypeID
) temp;

我希望得到单个的结果，即子查询返回。 例如：

planTotalAmount  |  discountTotalAmount
10                | 2                   `

但我正在

planTotalAmount  |  discountTotalAmount
10                | 0                   
0                 | 2                   `

如何解决这个问题？

Answer 1

汇总case...end表达式：

select
    sum(case temp.lineItemTypeID when 1 then temp.tt else 0 end case) as planTotalAmount,
    sum(case temp.lineItemTypeID when 2 then temp.tt else 0 end case) as discountTotalAmount
from (
        SELECT
            lineItemTypeID,
            sum(lineitemAmount) as tt 
        from tbl_invoicelineitem
        where date(lineItemcreatedDate) IS NOT NULL
        group by lineItemTypeID
    ) temp;