SQLITE如何在同一查询中划分两个计数结果

Question

我当前的代码:

SELECT VENDOR.[VENDOR_NAME], DEVICE.[DEVICE_NAME], DEVICE.[PK_DEVICE],MODELDEVICE.[FK_MODELDEVICE_DEVICE],

COUNT(RESULT.[FK_RESULT_COMMAND]) AS TOTAL_TESTS,
COUNT(case when TYPERESULT.[TYPERESULT_NAME]='ERROR' then 1 else null end) as ERROR,
COUNT(case when TYPERESULT.[TYPERESULT_NAME]='OK' then 1 else null end) as OK,
COUNT(case when TYPERESULT.[TYPERESULT_NAME]='SKIP' then 1 else null end) as SKIP,
COUNT(DISTINCT PK_COMMAND) AS COMMAND_COUNT, 
COUNT(DISTINCT RESULT_ORDER) AS RESULT_COUNT

问题是我需要另一列，其中包含将总 ERROR 结果除以 TOTAL_TESTS 结果的结果，但我不知道该怎么做

Answer 1

在这种情况下，我更喜欢使用 SUM()，而不是 COUNT()。我想你会明白为什么，因为平均值也很容易计算:

    COUNT(*) AS TOTAL_TESTS,
    SUM(case when TYPERESULT.[TYPERESULT_NAME] = 'ERROR' then 1 else 0 end) as ERROR,
    SUM(case when TYPERESULT.[TYPERESULT_NAME] = 'OK' then 1 else 0 end) as OK,
    AVG(case when TYPERESULT.[TYPERESULT_NAME] = 'ERROR' then 1.0 else 0 end) as ERROR,
    . . .

注意1.0的使用。这是因为SQLite进行整数除法，所以我们需要传入一个非整数值。