Combo Box Data Binding

This is an example of how to fill a combo box with data from a table.

1. First complete the lesson on regular data binding and open it
2. Unless you already have a table named Genders in the People database, create a new table in Design view as follows:
    

   Column Name	Data Type	Length	Addition Properties
   GenderID	int		Set Primary Key Identity: Yes
   Gender	varchar	20	Allow Nulls: Unchecked

3. Save it as Genders and fill it up as follows:
    

   GenderID	Gender
   	Unknown
   	Female
   	Male

4. Close the table
5. Open the Persons table in Design view and, in the first empty column, create a new field as follows:
    

   Column Name	Data Type	Length	Addition Properties
   PersonID
   FirstName
   LastName
   GenderID	int

6. Save the table as Persons
7. Right-click GenderID and click Relationships...
8. Set the Primary Key Table and the Foreign Key Table fields as GenderID
    
   
9. Click Close
   You can fill out the table with a few records
    
   

Creating a Data Bound Combo Box

.

Practical Learning: Creating a Database Using the Query Analyzer

1. Open the ExoADO1 application
2. Click the text box on the right side of Gender and press Delete
3. Add a new combo box where the GenderID text box was:
    

   Control Name Text Additional Properties ComboBox cboGender   DropDownStyle: DropDownList

4. To create a data source for the combo box, from the Data section of the Toolbox, click SqlDataAdapter and click the form
5. Click Next
6. In the combo box, select Server.People.dbo and click Next
7. Accept the default Use SQL Statements radio button and click Next
8. Click Query Builder...
9. From the Tables property page of the Add Table dialog box, click Genders. Click Add and click Close
10. In the upper section of the Query Builder window, click the GenderID and the Gender check boxes
11. Click OK
12. Click Next and click Finish
13. To create a data set for the genders, right-click sqlDataAdapter2 and click Generate Dataset...
14. Accept the Existing radio button and accept the Genders check box
15. Click OK
16. On the form, click the combo box
17. In the Properties window, set the properties as follows:
    DataSource: dsPersons1.Genders
    DisplayMember: Gender
    ValueMember: GenderID
    DataBindings -> SelectedValue: dsPersons1 - Persons.GenderID
18. Double-click an empty area of the form and change the Load event as follows:
     

    private void Form1_Load(object sender, System.EventArgs e) { sqlDataAdapter2.Fill(dsPersons1, "Genders"); sqlDataAdapter1.Fill(dsPersons1, "Persons"); }

19. Press Ctrl + F5 to test the application