like operator issue

Question

I have a dom table

select * from dom

dom table details:

id    name     skills
1     do         


        

Answer 1

in order to handle all possible cases (beginning of string, end of string, between 2 delimiters) you would need the inefficient (can't use an index)

SELECT *
FROM   dom
WHERE  CONCAT(',', skills, ',') LIKE '%,C,%'
       AND CONCAT(',', skills, ',') LIKE '%,C++,%' 

The best answer would be to put your database into at least first Normal Form!

A separate skills table and skills/person matrix table is much more efficient to search and easier to work with (e.g. removing an individual skill)

If you need a query that would bring back records in doms who match both C and C++ (assuming the same schema as jimmy_keen's answer) this could be done with a self join to get the intersection, the intersect operator, or using other relational division techniques such as

SELECT d.name
FROM   dom d
       JOIN dom_skills ds
         ON ( d.id = ds.id_dom )
       JOIN skills s
         ON ( ds.id_skill = s.id )
WHERE  s.name IN ( 'C', 'C++' )
GROUP  BY d.id,
          s.id,
          d.name
HAVING COUNT(DISTINCT s.name) = 2