my sql table column accepting "0" as value

I have two tables one is members table with columns member id , member first name, member last name. I have another table guest passes with columns guest pass id and member id and issue date .

I have a list view that will displays guest passes details (I.e) like member name and issue date and I have two text boxes those are for entering member name and issue date .

开发者_运维知识库

member name text box is auto complete text box that working fine....

but the problem is when I am entering the name that is not in member table at this time it will accept and displays a blank field in list view in member name column and member id is stored as "0" in guest pass table ......

I don't want to display the member name empty blank and I don t want to store "0" in guest pass table

and this is the insert statement

          sql2 = @"INSERT INTO guestpasses(member_Id,guestPass_IssueDate)";
          sql2 += " VALUES(";
          sql2 += "'" + tbCGuestPassesMemberId.Text + "'";
          sql2 += ",'" + tbIssueDate.Text + "'";

guestpassmemberId = memberid

is there any validation that need to be done

and this is the auto complete text box statement

           sql = @"SELECT member_Id FROM members WHERE  concat(member_Firstname,'',member_Lastname) ='" + tbMemberName.Text+"'";

 dt = GetData(sql, mf);

         if (dt != null)
         {
            if (dt.Rows.Count > 0)
            {
                tbCGuestPassesMemberId.Text  = Convert.ToInt32(dt.Rows[0]  ["member_Id"]).ToString();
            }
         }

can any one help me on this ... is there any type of validation with sql query

pls help me .....

---

You can validate the values before passing them to the INSERT. Additionally you can also set a constraint to validate versus a regular expression in SQL.

SQL constraints

To validate before inserting you should have something like this:

  private void validateData(Long memberId) {
       //Pseudo code Depends on how you are connecting to your database...
       SQLQuery query = getQuery("existsMemberId");
       query.setParameter("memberId");
       executeQuery(query);
       // If the query returns something then the reference exists and it is ok to proceed
  }

In the file you are storing your queries...

   #existsMemberId
   select 1
   from members mem
   where mem.id = :id <-- parameter

Additionally you should make foreign key constraint between members and guest passes with ID as the foreign key:

   ALTER TABLE GuestPasses
   ADD CONSTRAINT fk_memberId
   FOREIGN KEY (id)
   REFERENCES Members(id)