Dictionary

The System Definition | Dictionary module has an entry for each table and column in the database. As direct access to the database is not provided to ServiceNow customers, the dictionary offers a way to access the information on the database schema. It is also referred to as the data dictionary.

The Dictionary module lists data stored in the sys_dictionary table, referred to as the dictionary entry. It is equivalent to the database dictionary property of the tables and column objects in any RDBMS.

It lists both the tables and columns defined in the instance, as shown in the following screenshot:

If the Column name field is empty and the Type field is set as Collection, then the record is a table's definition. As shown in the preceding screenshot, for the Incident table, the Column name field is empty and the Type is set as Collection-this means that the record is the dictionary definition of the Incident table, whereas other records belonging to the table incident have the column name and type set as something other than Collection - it means they are the dictionary definition of the columns (fields) in the Incident table.

We can click on the info icon next to the record of the Incident table definition (collection) to load in the form detail page. We can activate features such as the auditing and text index or set some advanced attributes in the detail form (see Chapter 13, Advanced Database Features).

Similarly, we can click on the info icon, as highlighted in the following screenshot, next to the definition of the caller_id field of the Incident table, to view and manage the dictionary properties of the field:

Once the detail form page is loaded, we can modify field properties such as the field type, column label, or the table's display field by setting them as read-only or mandatory by simply editing the form fields:

We will be covering the use of different related tabs in the Dictionary detail form in Chapter 6, Introduction to ServiceNow Scripting.