Extension Overview

MM Table

Now, let us assume that you want to lend your CD to your friends. Well, even with friends it is useful to keep trace of your CD! One solution is to build a new table which will be in a MM-relation with your main table. One CD can have been borrowed by several friends.

In this table tx_savlibraryexample3_lending, the name of each friend is kept as well as its phone number, its email, the lending date and the return date. All the lending operation will be displayed in a folder Lendings (Prêts in French).

A field rel_lending was created by means of the SAV Library Kickstarter in the tx_savlibraryexample3_cds as a relation n:n with the table tx_savlibraryexample3_lending.

• cutLabel = 1; means that the label of this field will not be displayed (it is just a personal choice !)
• maxSubItems = 5; overrides the Max number of relations value (it is also a personal choice !)

In the Edit view, almost the same configuration is used. The attribute addDelete will add a delete icon in front of each item in the sub-form so that you can delete them.

Let us recall that the Context Sensitive Help provides information on the attributes that can be used. In following captions, three different attributes are used:

• noDefault = 1; is an attribute for Date type fields. It means that no default value, i.e. the current date, will be displayed when a new item is created.
• fusion = begin; and fusion = end; are General attributes which can be used almost with every fields. fusion = begin; starts the process of writing fields consequently on the same line, while fusion = end; stops the process.
• func = makeEmailLink; belongs to Functions attributes, they can also be used almost with every fields for which it makes sense to apply thy function. It will generate an email link the current value of the field.

Queries

A GROUP BY clause is needed in the Query to display only one item per CD in the List view. If this clause is not added, we get as many repeated outputs for same item as the number of sub-items associated with it (the reason is that SAV Library Plus extension generates left join relations between the tables).