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Goal:
Learn about the use and functionality of the JumpStart DNN Fieldextentions.

General:
The fieldextentions are what make the database "SMART".
The information that the ApplicationBuilder needs to code for the needed functionality is in the extention on a datafield.
There are extentions that code for the GUI. For example, the Member table that you created shows only the recordindex in the tableview's datagrid.
So, in order to get more information shown in the recordview, you have to append an extention to the fieldnames that you want to show in the datagrid.

Beware: When you add or remove an extention in a JumpStart DNN table, you are effectively changing the SQL datatable.
This forces you to re-install the module, because the changed fieldnames need to be changed in all the code as well.
See also: The Installable PA zipfile (How to handle your modules when updating?)

Execution:
Introduction:

Open your DatabaseBuilder and open Tab "Conventions".
This is the place where the SQL tablefield extentions are located. (I have to do some translayions yet....)


The SQL tablefield extentions are the building blocks of the "Smart Database Concept".
They define the coding by the ApplicationBuilder of certain functions that make your modules work as one application.

A copy of these extentions is drawn to every tab that defines a table. Thus making maintenace easy, every change you make here is immediately visible in the TableTabs.
Just for the Extention Description is an altenative, because this text is put into memoryfields in a row of cells in the TableTabs. Use the hidden function behind the "Primary Key" cell to rebuild the memofield. WEspecially handy when you change the descrition text for your own convenience.
 

The ## column references the extention in the TableTab:
















   

The FieldType depict the most likely field types that this extention can be used for.




Selecting an extention is done by changing the "Dash" in the ExtentionGrid into a "Tick".
This will result an a change of the SQL fieldname; the extention is added to the fieldname.












   

The SQL fieldtype tell you something about the defaults for your FieldTypes.
In general (example) a datefield in your application woul be a VarChar(10) SQL type.






Continue on: FieldExtentions: Part 1
Continue on: FieldExtentions: Part 2

 ---->> Lesson 10: Testing your module