Question

i have the following code

Regex R = new Regex("my regex");
var q = from c in db.tble1
        where R.IsMatch(c.text)
        select c;

and while debugging i saw in the q result this message

Method ‘Boolean IsMatch(System.String)’ has no supported translation to SQL.”} System.SystemException {System.NotSupportedException}

so what have i done wrong ?

Edit:I learned that the method has no supported translation to SQL
but how to solve this

Answer 1

Regex has no supported translation to SQL. The error says it all. You can’t use regex in LINQ to SQL.

Try using a like or substring comparison instead:

var q = from c in db.tble1
        where c.text.StartsWith("x") && c.text.Substring(2, 1) == "y"
        select c;

Or, you could perform an in memory regex comparison. You can do this by calling ToList() before using the Regex:

Regex R = new Regex("my regex");
var q = from c in db.tble1.ToList()
        where R.IsMatch(c.text)
        select c;