计算选择语句中的位置和位置

Question

Hi I am trying to write a stacked bar chart in mysql, and first I need to get the query right, and need some help.

Currently I have:

SELECT
COUNT(TargetDate) AS Planned,
COUNT(StartDate) AS Completed,
MONTHNAME(TargetDate) AS `Month`,
StartDate,
AssessmentStatus
FROM AuditCycleAssessments
WHERE (Year(TargetDate) = Year(now()))
GROUP BY MONTHNAME(TargetDate)
ORDER BY Month(TargetDate)

which works just fine and looks like screenshot

However I need to change the 3rd line to include its own where statement, something like...

  (COUNT(StartDate) if AssessmentStatus=3) AS Completed,

So number 1, can someone help me achieve this.

Thanks

Answer 1

check how to write IF But here you can not write if you should use CASE

SELECT
COUNT(TargetDate) AS Planned,
COUNT(CASE WHEN AssessmentStatus=3 THEN StartDate END) AS Completed,
MONTHNAME(TargetDate) AS `Month`,
StartDate,
AssessmentStatus
FROM AuditCycleAssessments
WHERE (Year(TargetDate) = Year(now()))
GROUP BY MONTHNAME(TargetDate)
ORDER BY Month(TargetDate)

Answer 2

Do a conditional COUNT with a CASE statement

SELECT
    COUNT(TargetDate) AS Planned,
    COUNT(CASE WHEN AssessmentStatus=3 THEN StartDate END) AS Completed,
    MONTHNAME(TargetDate) AS `Month`,
    StartDate,
    AssessmentStatus
FROM AuditCycleAssessments
WHERE (Year(TargetDate) = Year(now()))
GROUP BY MONTHNAME(TargetDate)
ORDER BY Month(TargetDate)

Answer 3

类似于以下内容的内容可能会为您服务，未经您的情况测试，但它应该可以工作。

Sum(IIf([AssessmentStatus]=3 AND [StartDate] NOT IS NULL,1,0)) AS Completed,