There is a distinction between the table (data definition and data container) and the data (the contents of a table). The table definition describes the identification information, data structure, validation rules, storage, and retrieval of the data that is stored in the table (container). This definition is defined by its design and can only be changed by a developer. The table data is the variable content that originates from user activities. The place where we can see the data being explicitly referenced, independent of the table as a definition of structure, is in Permission Sets. In the following screenshot, the data is formally referred to as Table Data:

Figure 2.1 – Permission Set showing Table Data Object Type

The table is not the data – it is the definition of data contained in the table. Even so, we commonly refer to both the data and the table as if they were the same. That is what we will do in this book...

Now, we can take our knowledge of tables and expand our WDTU application. Our base Radio Show table needs to be added to and modified. We also need to create and reference additional tables.

Although we want to have a realistic design in our sample application, we will focus on changes that illustrate features in the Business Central table design that this book’s authors feel are among the most important. If there are capabilities or functionalities that you feel are missing, feel free to add them. Adjust the examples as much as you wish to make them more meaningful to you.

Creating and modifying tables

In Chapter 1, Introduction to Business Central, we created the Radio Show table for the WDTU application. At that time, we used the minimum fields that allowed us to usefully define a master record. Now, let’s set properties on existing data fields, add more data fields, and create an additional data table to which the Radio Show...

For this discussion, we will first divide tables into two parent categories, depending on whether they are extensible by code, or not. Let’s take a closer look.

Extensible tables

As developers, we can change both the definition and the contents of extensible tables. Those tables reside in the Base Application, Business Foundation and System Application modules of Business Central.

The following table types are included in the extensible tables category, and are part of the Base Application module:

• Master data
• Journal
• Template
• Entry tables
• Subsidiary (supplementary) tables
• Register
• Posted document
• Singleton
• Temporary

Let’s look at these in detail.

Master data

The master data table type contains primary data (such as customers, vendors, items, and employees). In any enhancement project, these are the tables that should be designed first because everything else will be based on these tables...

In this chapter, we focused on the foundation level of Business Central data structure: tables and their internal structure. We worked our way through the hands-on creation of a number of tables and their data definitions in support of our WDTU application. We briefly discussed field groups and how they are used. We also discussed how we used pages to view and maintain the data stored in tables. We will discuss pages in more detail in Chapter 4.

We identified essential table structure elements, including properties, object numbers, triggers, keys, and SumIndexFields. Finally, we reviewed the various categories of tables that can be found in Business Central. Now, you can identify what tables are used in standard functionality, locate what properties and AL procedures are used to accomplish business logic and start to create your own.

In the next chapter, we will dig deeper into the Business Central data structure to understand how fields and their attributes are assembled...

1. Which of the following is a correct description of a table in Business Central? Choose two:
   • A Business Central table is the definition of data structure
   • A Business Central table includes a built-in data entry page
   • A Business Central table can contain AL code, but that should be avoided
   • A Business Central table should implement many of the business rules of a system

   ANSWER: A Business Central table is the definition of data structure, and a Business Central table should implement many of the business rules of a system

2. All PKs should contain only one data field. True or false?

   ANSWER: False

3. System tables cannot be extended. True or false?

   ANSWER: True

4. Which of the following are table triggers? Choose two:
   • OnInsert
   • OnChange
   • OnNewKey
   • OnRename

   ANSWER: OnInsert and OnRename

5. In a table extension, a single key can contain fields from both the base and extension object. True or false?

   ANSWER: False

6. Because setup tables only contain one record, they do not need to have...