=============
Lookup fields
=============

Now, we will create the "Contacts" journal and use lookup fields to connect contacts to customers. Lookup fields allow an element of one item (i.e., catalog or journal) to reference an element from an other item.

Select the "Journals" group in the project task tree, and add a new journal in the
same way that we created the "Customers" catalog. Journals, like catalogs, correspond to different tables in the database. See this :doc:`link </faq/faq_catalogs_vs_journals>` for more information.

First, add a "Contact date" field of the ``DATETIME`` type,
and a "Notes" field of the ``TEXT`` type.

Then, add the
:doc:`lookup field </programming/data/lookup_fields>`
"Customer", which will store a reference to a record in the "Customers" catalog.

.. image:: /intro/_images/contacs_cutomer_fld.png
	:align: center
	:alt: Adding Customer field

To create a lookup field, first specify its caption and name, and leave the type
empty. Then go to the **Lookup** tab and click the button to the right of the **Lookup item** input.


.. image:: /intro/_images/cutomers_lookup_tab.png
	:align: center
	:alt: Cutomer lookup tab

This brings up a list of items. Double click the "Customer" record to select it.

.. image:: /intro/_images/cutomers_lookup_item.png
	:align: center
	:alt: Selecting Customer lookup item

Next, we need to specify a lookup field. This is how the customer will be located.
Here we choose "Lastname". Leave the other fields empty and press **OK**.


.. image:: /intro/_images/lastname_lookup.png
	:align: center
	:alt: Lastname lookup field

Repeat this procedure to add the "Firstname" and "Phone" lookup fields.
For these fields, we specify the "Customer" field as their **Master field** attribute.
This connects them to the first "Lastname" lookup field we created, so that all three
lookup fields refer to the same customer.

.. image:: /intro/_images/contacts_firstname.png
	:align: center
	:alt: contacts_firstname.png

.. image:: /intro/_images/phone_lookup.png
	:align: center
	:alt: Phone lookup field
	
Click the **OK** button to save the "Contacts" item. 

.. image:: /intro/_images/contacts_sql.png
	:align: center
	:alt: Contacts sql

As you can see, there are no "FIRSTNAME" and "PHONE" fields in the ``CRM_CONTACTS`` 
table. This is due to the fact that we have set **Master field** attribute of these 
fields to "Customer". The "Customer" field will store a reference to a record in the
"Customers" catalog, and this record will have the "Firstname" and "Phone" fields.

Refresh the project page and, in the "Contacts" page, click the **New** button.
You will see that there is a small button to the right of the "Customer" input.

.. image:: /intro/_images/customer_input.png
	:align: center
	:alt: Customer input

Click on it and select a record in the "Customers" catalog: the
fields "Customer", "Firstname" and "Phone" will be filled automatically.


.. image:: /intro/_images/customer_input_selected.png
	:align: center
	:alt: Customer input selected