When you create a table in Dexterity, you’ll use or define several elements required for the table to store and access information properly, such as fields, keys and table relationships. Before you create tables, be sure you have previously defined all the fields that you’ll be using to store information in the table.
If you are creating applications that integrate with Microsoft Dynamics GP, be aware that Microsoft Dynamics GP table structures CANNOT be modified. Because you can do so, does not mean your should. Any additional information (say for example Customer Hotel Preferences) must be stored in extended tables with the same primary key used by the original Dynamics GP table, which in turn will allow you to setup table relationships. Maintaining GP tables intact will facilitate applying service packs and performing upgrades to your Dynamics GP application.
You will use the Table Definition window to create a table.
|Table Definition window|
Understanding Table Buffers
Each time a table is attached to a form, a table buffer is automatically created for that table. If you attach a table to more than one form, each form will have its own table buffer for that table. The following example shows all the tables attached to the RM_Customer_Maintenance form. When the form is opened in the application, each table buffer is loaded into memory ready to receive a record.
|Form Definition window|
It is perhaps a good time to check David's latest article on discarding changes from transaction windows as it is very intertwined with the implementation of forms, windows, and table buffers, along with some referential integrity issues that may show up when saving information to multiple tables at once.
Common Table Operations
Now that you understand some of the concepts let’s move on to common table operations. Typically, as with other development environments, data in tables is a direct result of users’ interaction with the application windows. Data is constantly transported back and forth from windows to tables and from tables to windows where users can perform subsequent operations on the data such as create new records, retrieve existing records, perform updates, and delete records. In Dexterity, this transport of data is accomplished via scripting -- SanScript in particular.
The SanScript language is equipped with four powerful statements that are the basis for table operations:
- get statement
- change table statement
- save table statement
- remove table statement
My next installment will describe in detail how these statements work and the do’s and don’ts when working with them.
Until next post!
Mariano Gomez, MVP