Alternative to using LIMIT keyword in a SubQuery i

2020-01-27 06:37发布

I have a table TEST with the following columns :

code_ver (VARCHAR)
suite (VARCHAR)
date (DATE)

Now I want to select 10 rows with a distinct value of code_ver & code_ver NOT LIKE '%DevBld%' sorted by date desc.

So I wrote the following query:

select * 
  from test 
 where code_ver IN (select DISTINCT code_ver 
                      from test 
                     where code_ver NOT LIKE '%DevBld%' 
                     ORDER by date DESC LIMIT 10);

This query should ideally work, but my version of MySQL says :

This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'

Can someone suggest me an alternative to this query?

4条回答
We Are One
2楼-- · 2020-01-27 06:54

You can also use same query, just by adding one extra layer of select before subquery. and that's it. It will work.

select * from test 
where code_ver IN (select * from (select DISTINCT code_ver 
                      from test 
                     where code_ver NOT LIKE '%DevBld%' 
                     ORDER by date DESC LIMIT 10) as t1);
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家丑人穷心不美
3楼-- · 2020-01-27 06:55

Answer suggested by Layke is wrong in my purview. Intention of using limit in subquery is so main query run on limited records fetched from subquery. And if we keep limit outside then it makes limit useless for subquery.

Since mysql doesn't support yet limit in subquery, instead you can use JOIN as follows:

       
    SELECT * FROM test
    JOIN 
    (
        SELECT DISTINCT code_ver 
        FROM test 
        WHERE code_ver NOT LIKE '%DevBld%' 
        ORDER BY date DESC LIMIT 10
    ) d
    ON test.code_ver
    IN (d.code_ver)
    ORDER BY xyz;
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何必那么认真
4楼-- · 2020-01-27 06:56

Put the subquery in a derived table:

   SELECT test.*
     FROM test
LEFT JOIN (SELECT DISTINCT code_ver
             FROM mastertest
            WHERE code_ver NOT LIKE '%DevBld%'
            ORDER BY `date` DESC
            LIMIT 10) d
    USING (code_ver)
    WHERE d.code_ver IS NOT NULL;

(You could also RIGHT JOIN that, of course, and drop the outer WHERE condition.)

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神经病院院长
5楼-- · 2020-01-27 07:11

The error you are getting is not exactly because of the version of MySQL. I think all versions support that. You have to change the LIMIT 10 place and place it after ")". Let me know if it works for you. I ran the bellow one on mine and it works.

E.g.

SELECT * FROM test where name IN (
           SELECT DISTINCT name 
           FROM projects 
           WHERE name NOT LIKE "%DevBld%"  
           ORDER by date_created DESC
 ) LIMIT 10;

Update: Try the one below, this way order would work:

 SELECT * FROM  automation.e2e_projects WHERE name IN (
       SELECT DISTINCT name 
       FROM automation.e2e_projects
       WHERE name NOT LIKE "%DevBld%"
 ) ORDER by date_created DESC LIMIT 10;
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