## Query Option dialog

This dialog appears when you click Query > Current Query Option on the menu bar of the Query Editor window. It helps you to set the settings for a query. See the dialog.

The following are details about options in the dialog:

Join on Foreign Keys

Specifies to automatically join tables in the query through a reference from Table A to a primary key in Table B. For example, an order form in Table A shows information on purchases that are made by a customer. It can also show this customer's ID #. That customer ID # refers to a record in Table B that lists a specific address, phone number, name, etc for that customer. The customer ID # in Table A is a foreign key because it links the customer's ordering information in Table A to the customer's information in Table B.

Join on Primary Keys with Same Names

Specifies to automatically join tables in the query through a field or a combination of fields that uniquely and specifically identifies a record. For example, your credit card number is a primary key because it specifically links to your birthday, credit history, address, etc.

Join on Same Names

Specifies to automatically join tables in the query through a link between two columns in which the same name is found in two different tables.

Show Mapping Names

If selected, the full name of the column in the table will be displayed in the criteria panel of the Query Editor.

Show Table Names

If selected, the table that each column belongs to will be displayed in the criteria panel of the Query Editor.

Warn When Cartesian Product Exists

Specifies whether or not to display a warning when a Cartesian exists. A Cartesian product is used when tables link together with no specifications.

For example, Table A has three values: A, B and C and Table B has three values: 1, 2 and 3. Value A matches value 1, value B matches value 2, and so on. This is a specific match.

A Cartesian product could have value A matching with 1, 2 and 3, and value B matching with 1, 2 and 3, and so on. Depending on the data values Cartesian products can produce large and complicated datasets since unnecessary information may be contained.