Join vs. sub-query

Question

I am an old-school MySQL user and have always preferred JOIN over sub-query. But nowadays everyone uses sub-query, and I hate it; I don\'t know why.

Answer 1

If you want to speed up your query using join:

For "inner join/join", Don't use where condition instead use it in "ON" condition. Eg:

     select id,name from table1 a  
   join table2 b on a.name=b.name
   where id='123'

 Try,

    select id,name from table1 a  
   join table2 b on a.name=b.name and a.id='123'

For "Left/Right Join", Don't use in "ON" condition, Because if you use left/right join it will get all rows for any one table.So, No use of using it in "On". So, Try to use "Where" condition