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two where conditions in a mysql query

开发者 https://www.devze.com 2022-12-24 06:29 出处:网络
I have a table like below date|dom|guid|pid|errors|QA|comm| |2010-03-22|xxxx.com|jsd3j234j|ab|Yes|xxxxxx|bad|

I have a table like below

|date|dom|guid|pid|errors|QA|comm|
|2010-03-22|xxxx.com|jsd3j234j|ab|Yes|xxxxxx|bad|
|2010-03-22开发者_如何学Go|xxxx.com|jsd3j234j|ab|No|xxxxxx||
|2010-03-22|xxxx.com|jsd3j234j|if|Yes|xxxxxx|bad|
|2010-03-22|xxxx.com|jsd3j234j|if|No|xxxxxx||
|2010-03-22|xxxx.com|jsd3j234j|he|Yes|xxxxxx|bad|
|2010-03-22|xxxx.com|jsd3j234j|he|No|xxxxxx||

I want to retrieve the total count of "dom" referred to each "QA" and also I need the count of "errors" detected by the "QA"

SELECT date, count(dom), QA 
  FROM reports 
  WHERE date="2010-03-22" 
  GROUP BY QA
|2010-03-22|2|ab|
|2010-03-22|2|if|
|2010-03-22|2|he|
SELECT date, count(dom), count(errors), QA 
  FROM reports 
  WHERE errors="Yes" 
  GROUP BY QA
|2010-03-22|1|ab|
|2010-03-22|1|if|
|2010-03-22|1|he|

I want to combine the above two queries, is it possible.

If I use the below query, I am not getting the desired result.

SELECT date, count(dom), QA, count(errors) 
  FROM reports 
  WHERE date="2010-03-22" 
    AND errors="Yes" 
  GROUP BY QA

I want the below output

|2010-03-22|2|ab|1|
|2010-03-22|2|if|1|
|2010-03-22|2|he|1|


You can do this with:

SELECT date, COUNT(dom), QA, COUNT(NULLIF(errors, 'No')) FROM reports WHERE date="2010-03-22" GROUP BY QA

To explain how this works: COUNT returns the number of non-null values. We can use this to our advantage by turning errors with 'No' into NULL, so COUNTwon't count them. We do this with the NULLIF function, which returns NULL if the first and second arguments are equal.


Try using OR in place of AND:

.... date="2010-03-22" OR errors="Yes" GROUP BY QA
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