Question

表格如下：table name ='seat'，列为'seat1'，'seat2'，'seat3'，'seat4'，'seat5'。

id | seat1 | seat2 | seat3 | seat4 | seat5 
 1 |   0   |   1   |   1   |   0   |   1
 2 |   1   |   1   |   0   |   1   |   0
 3 |   1   |   0   |   1   |   1   |   1

我需要一个sql查询，它为我提供以下查询。当id = 1时，输出将是

seat2, seat3, seat5

如果id = 2，则输出

seat1, seat2, seat4

如果id = 3，则输出

seat1, seat3, seat4, seat5

Answer 1

你的意思是这样的吗？如果没有帮助我理解，我可以调整查询逻辑......

  SELECT
        'Occupied Seats = {' +
        CASE WHEN seat1 = 1 THEN '1, ' ELSE '0, ' END +
        CASE WHEN seat2 = 1 THEN '1, ' ELSE '0, ' END +
        CASE WHEN seat3 = 1 THEN '1, ' ELSE '0, ' END +
        CASE WHEN seat4 = 1 THEN '1, ' ELSE '0, ' END +
        CASE WHEN seat5 = 1 THEN '1}' ELSE '0}' END 
    FROM seats 
    WHERE 1 IN (seat1,seat2,seat3,seat4,seat5)

Answer 2

根据我的理解，你正在寻找只占用的座位。我基于这种理解准备了以下查询。如果理解存在差距，请评论：

select * from 
(
select 'seat1', seat1 as occupiedStatus from [table]
union
select 'seat2', seat2 as occupiedStatus from [table]
union
select 'seat3', seat3 as occupiedStatus from [table]
union
select 'seat4', seat4 as occupiedStatus from [table]
union
select 'seat5', seat5 as occupiedStatus from [table]
) seatsPivot
where occupiedStatus = 1 ;

如何选择不同列名的名称是指在表的一行中具有相同值的列的标题？

2 个答案: