Cascading Drop-down Lists in a parent, child relationship

I see this topic come up over and over again in SharePoint. I am going to elaborate on this post when I have a chance.

I am creating this post as a reminder to myself of what I did to make it work.

i started by downloading and installing an add-on from the following site:

http://datacogs.com/datablogs/archive/2007/08/26/641.aspx

Now when I create a new column – I have the option to create a column type of parent drop-down list or child drop-down list.

The selection from the parent will filter the results in the child drop-down

I had to enable Auto Postback on the drop-downs to make it work properly.

If anyone needs this immediately, let me know and I’ll make is a priority.

UPDATE

I am finally able to get around to documenting this procedure. I needed to get it done, because I’m pretty sure that I would have a hard time remembering what I did if I had to start again from scratch. Here is my scenario for the cascading (parent-child) drop-down lists:

I have an application that tracks the progress of programming tickets through the company’s specification review process. The initial programming request contains two drop-downs; one for Project and another for Program. My users wanted the Program list to be filtered to only show programs that belong to the selected Project. The user would select a Project from the first drop-down list and it would filter and refresh the options in the second list.

Setup

After installing the Datacogs program, I created a list containing the Projects. The list contains one column called Project Name.

For Example:

• Project 1
• Project 2
• Project 3
• etc. 

Next, I created the Programs list. The list contains two columns; one with Program Name and the other a lookup to the Project list. Entries in the Program list are associated to the Project list.

For Example:

• Program 1 – Project 2
• Program 2 – Project 2
• Program 3 – Project 1
• Program 4 – Project 3
• etc.

Note: Both of these lists can be created in SharePoint WITHOUT the Datacogs add-in.

Connect the dots

Now comes the fun part. In my new list, the Specification Tracker, I need to perform the cascading drop-down. When I create a new column, with the Datacogs add-in installed, I have an option to create the column with a column type of Parent Drop Down list.

I create a column called Project and set the type to Parent Drop down list. The Parent drop-down list contains a new option:

Parent Drop Down List Details

Enter a SharePoint site URL (in this Farm)then click the Load Lists button. Select a List and Column in the remaining dropdowns Site URL List Name Column For Value Column For Text

I have to specify the site that contains the list (to perform the lookup on). I really like this feature as I should be able to select lists from any of the SharePoint sites on the same collection. I haven’t tested the feature yet, as both times I’ve used it, the lists were always on the same site.

Once you select the site, click Load Lists. Now you can select the List Name from the drop-down. I selected the Project list I created earlier. Then I have to select the Column for Value (that’s what the selection will pass to the child list). Finally select the column for Text – which is what will display on the screen in the drop-down.

Follow the same steps for the Child drop-down list, except that you have one more selection to make. There is an additional drop-down for Column to Join to Parent. In my case, I selected the Project column in the Program List as the column to join.

Presto, you are done. If you open the newform.aspz for the list, and select a Project, the options available in the Program list will be filtered to only show the ones that belong to that project.