Join is not working in LINQ statement

I am new to LINQ. I have a GridView which I am populating using LINQ. My LINQ statement is taking query string from previous page. The query string is in string format. Here is the code:

 protected void Page_Load(object sender, EventArgs e)
    {
        string getEntity = Request.QueryStrin开发者_JAVA技巧g["EntityID"];
        int getIntEntity = Int32.Parse(getEntity);
        OISLinqtoSQLDataContext db = new OISLinqtoSQLDataContext();
        var tr = from r in db.Users
                 join s in db.Entities on r.UserID equals s.ID
                 where s.ID = Request.QueryString["EntityID"]
                 select new
                 {
                     //To Show Items in GridView!
                 };

        GridView1.DataSource = tr;
        GridView1.DataBind();

    }

s.ID is not equal to QueryString. S.ID is a type of int and QS is a type of string. How should I convert this QS into an integer? Thank you!

Make sure you are using == not = and use the int version of the "getEntity" variable.

protected void Page_Load(object sender, EventArgs e)
{
    string getEntity = Request.QueryString["EntityID"];
    int getIntEntity = Int32.Parse(getEntity);
    OISLinqtoSQLDataContext db = new OISLinqtoSQLDataContext();
    var tr = from r in db.Users
             join s in db.Entities on r.UserID equals s.ID
             where s.ID == getIntEntity
             select new
             {
                 //To Show Items in GridView!
             };

    GridView1.DataSource = tr;
    GridView1.DataBind();

}

You should use your parsed integer value instead:

 var tr = from r in db.Users
             join s in db.Entities on r.UserID equals s.ID
             where s.ID == getIntEntity
             select new
             {
                 //To Show Items in GridView!
             };

Okay! Here it is:

My ID in Entity table is PK and EntityID in User Table is a type of int but no constraints. So this is

1-MANY Relationship.