Question

您好我有表徽章，其中包含facility列和date列（其他列并不重要）。我希望select count(*)看起来像这样：

DATE       | FACILITY 4 COUNT | FACILITY 1 COUNT
12/12/2012 | 234              |  647

我为facility 1和4编写了两个单独的查询，但是如何将其加入一个查询;

SELECT
    date,
    COUNT(*)
    FROM      badge
    WHERE     facility = 3
    AND       xtype = 19
    AND       date BETWEEN 'some_date' AND 'some_date'
    GROUP BY  date

另一个查询仅在设施值上有所不同。

编辑：这是informix数据库。

Answer 1

SELECT date,
       SUM(case when facility = 1 then 1 else 0 end) "FACILITY 1 COUNT",
       SUM(case when facility = 4 then 1 else 0 end) "FACILITY 4 COUNT"
FROM      badge
WHERE     (facility = 1 OR facility = 4)
AND       xtype = 19
AND       date BETWEEN 'some_date' AND 'some_date'
GROUP BY  date

Answer 2

尝试一下，

SELECT  date,
        SUM(CASE WHEN facility = 3 THEN 1 ELSE 0 END) `Facility 3 Count`,
        SUM(CASE WHEN facility = 1 THEN 1 ELSE 0 END) `Facility 1 Count`
FROM      badge
WHERE     xtype = 19 AND      
          date BETWEEN 'some_date' AND 'some_date'
GROUP     BY  date

加入同一张桌子

2 个答案: