unique strings from string column type in mySQL

I have a column in a database with a column type of string that holds catalog numbers. They can be in two formats. 1: 410998 2: 555336-18 The 18 in the dash number represents a length. So there could be multiple entries with the same base, just a different int after the dash. I am experiencing two issues: First, when using the catalognumbers in a SELECT statement, only those without dashes return anything. Is there something I need to do with my datatype in order to use: $item = "555336-18"; $sql = "SELECT * FROM products WHERE catalognumber = $item"; Second question, when I strip off the dash and following int(s), my select statement will work, even though the subtring I am then searching for doesn't really exist in the database. And if I have two numbers with that same subtring base they are both returned. For Example: $item1 = "555336-18"; $item2 = "555336-7"; $item = substr($item,0,6); $sql = "SELECT * FROM products WHERE catalognumber = $item"; Both items will be be returned, even without using %LIKE%. I'm guessing this all stems from my column type. Should I change it to something else, and if so what? Can anyone help out? Thanks, >> Mike Krisher