6. Project Tables¶
The tables included in the project are those required for traditional model development, and are always required unless explicitly mentioned otherwise.
6.1. Modes table¶
The modes table exists to list all the modes available in the model’s network, and its main role is to support the creation of graphs directly from the SQLite project.
The modes table has three fields, being the mode_name, description and mode_id, where mode_id is a single letter that is used to codify mode permissions in the network, as further discussed in Network.
An example of what the contents of the mode table look like is below:
6.1.1. Consistency triggers¶
As it happens with the links and nodes table (Network consistency behaviour), the modes table is kept consistent with the links table through the use of database triggers
18.104.22.168. Editing a mode in the modes table¶
Whenever we want to edit a mode in the modes table, we need to check for two conditions:
The new mode_id is exactly one character long
The old mode_id is still not in use in the network
For each condition, a specific trigger was built, and if any of the checks fails, the transaction will fail.
The requirements for uniqueness and non-absent values are guaranteed during the construction of the modes table by using the keys UNIQUE and NOT NULL.
22.214.171.124. Adding a new mode to the modes table¶
In this case, only the first behaviour mentioned above on Editing a mode in the modes table applies, the verification that the mode_id is exactly one character long and no new behaviours are needed. Therefore new triggers are not required.
126.96.36.199. Removing a mode from the modes table¶
In counterpoint, only the second behaviour mentioned above on Editing a mode in the modes table applies in this case, the verification that the old mode_id is not still in use by the network, and no new behaviours are needed. Therefore new triggers are not required.