Question

I have a table with java package names:

|id|pkg|
|1 |some.long.package.path|
|2 |com.admob.bla|

and a table that contains partial packages names form known advertisement frameworks.

|id|path_fragment|
|1 |.admob |

How can I retrieve packages whose value for pkg contains any of the ad_frameworks.path_fragment?

I just can’t find the substring check. All I find is people using like to compare to some string literal but never for comparing columns.

NOTE: I am using MySQL.

Answer 1

think you could do an inner join with a like

select p.id, p.pkg
from package p
inner join ad_frameworks adf on p.pkg like CONCAT('%', adf.path_fragment, '%')
--group by p.id, p.pkg

or as you pointed

select * 
from package p
inner join ad_frameworks adf on LOCATE(adf.fragment, p.pkg) > 0

or

select * 
from package p
inner join ad_frameworks adf on INSTR( p.pkg,adf.fragment) > 0

or

select * 
from package p
inner join ad_frameworks adf on POSITION(adf.fragment IN p.pkg) > 0

or

select * 
from package p
inner join ad_frameworks adf on REPLACE(p.pkg, adf.fragemnt, '') <> p.pkg

Well, you’ve got few choices 😉

SqlFiddle