Comparing arrays

So I finally got the multiple sections made from some dynamic dropdowns saved into the MySQL, i can implode and explode etc.

Now I want to search them.

I have a table of users with a col for "localStores" where i have a an array of the user's local stores stored as 234,135,10 etc

I then have a table of news articles, when the author writes the article they use a similar multiple select to choose the stores that story is applicable to.

When the user is logged in, I want to be able to pull each article that relates to their chosen stores.

Any ideas how to do this? I assumed arrays was the right way to go about this, but it is proving very difficult. I was hoping to be able to it MySQL side.

Thanks

Sam