Another Option for Creating Conditional Dropdowns

The most common and recommended method for creating conditional dropdown lists is using the three-table model. You can, however, design conditional dropdowns using another method:

• The conditional dropdown is created based on the relationship between only two tables

• Both tables must contain the field upon which the conditional dropdown depends.

So, to achieve this result:

...you would need to create these two tables:

• Employees

• Cities

Both the Employees and Cities tables need to include a Country field AND it's important that the values in these fields match.

When would I use this approach?

You might consider taking this approach when it's your practice to import data to maintain the field upon which the conditional field depends. For instance, if you want to maintain your parent Countries list, you could choose to:

• Create a table and a record into which you can import a list of countries

• In the Employees and the Cities table, make sure the Country field is a shared value field that uses the table and record you created in the previous step as its source. This ensures that your list of countries will always be the same.

Drawbacks to this approach

While it can certainly work, this approach is a bit more error-prone than the basic three-table scenario. The two-table method requires that you keep the "duplicate" field in both tables entirely in synch. If you choose not to implement the shared value recommendations above, you must always remember to update the country list in the Employees table when you update the country list in the Cities table.

Tutorial: Creating a conditional dropdown using a two-table relationship

Follow these steps to create a conditional dropdown, based on a single relationship between two tables. Note that, in this example, we're also creating a third table, only to hold the parent list of Countries.

Step 1: Create an application with three tables

Create the two tables and fields shown in the table below:

Step 2. Import or enter your countries

Add these records to your Countries table (either manually or by import)

• Canada

• England

• France

• United States

Step 3. Configure your shared value fields

In the Employees and Cities table, edit the Country field properties. For the source of these shared value fields, select the Countries: Country field.

Step 4. Create a relationship between the Cities and Employees tables

Your Employees table needs to have access to the city and country pairs in the Cities tables so that you can specify the appropriate city and  country when entering an employee record.

The relationships should be set up this way because one city has many employees

Reference and lookup fields in the details table

Once you've created this relationship, you should see this reference field in the Employees table:

Quickbase also creates a lookup field in the Employees table when you create this relationship:

For now, just make note of the reference  fields that Quickbase created. You'll use these later in the process.

Step 5: Enter your Cities

Populate your Cities table as follows:

Step 6: Set Conditional Behavior properties for your conditional field

Remember that your goal is to create a form where you can enter employee information and be able to filter the Cities list based on the employee's country. You can see that your Employees table now contains the reference field Related City--this is the field that you should define as conditional.

To set the Conditional Behavior property:

1. Access the field properties of the Related City field in the Employees table.
   
   

2. Check The values in this field depend on a selection in another field. (Note: You'll see this option only in the field properties for Reference fields; if you don't see it, you may have chosen the wrong field by mistake.)
   
   Quickbase asks you select fields to complete this statement: A selection in <field1> shows choices where <field1> = <field2>.

3. Set these conditions:

1. In the first dropdown, select Employees: Country. This tells Quickbase to check the value of the Employees: Country field to determine which cities to display.

2. In the second dropdown, select Cities: Country. This tells Quickbase to display only those cities that belong to the country the user selected.

4. Click Save.

Cleaning up your Employee form

Depending on the order in which you created your relationships, your Employee form may contain an extra field (City --Related Country). If this is the case, simply edit the form properties and remove the field from your form.

Testing  your conditional dropdown

Once you've completed these steps, you can test your conditional dropdown by adding a new employee, Colleen Garton, to your Toronto office.

To test the conditional dropdown:

1. From the Employees table, click + New Employee on the page bar.

2. Enter Garton and Colleen, for Last name and First name, respectively.

3. In the Country field, select Canada.

4. Click the Cities dropdown. Quickbase displays only Canadian cities: Toronto and Vancouver.

5. Select Toronto and click Save.

Related topics:

• Conditional Dropdowns

• Conditional Dropdowns: Basic Setup

• How To Add Cascading Dropdowns

• About table-to-table relationships

• Designating reference proxy fields