Configuring Data Sets

Data Sets enable you to add ‘custom’ tables to your database. You use Data Sets to collate, organize, and summarize data from elsewhere in the database, in a tabular format that can be queried from, for example, a List or a Report.

One of the main benefits of using Data Sets instead of Data Grids applies if your database is 'modular' and uses Group Templates and Group Instances. With such a database setup, you can use a Data Set to automatically collate data from the Group Instances that are associated with a Group Template. The Data Set's table contains one record for each instance of the Group Template. Records are automatically added or removed from the Data Set's table as instances of the Group Template are created or deleted. To benefit from this setup, you include in the Group Template the Data Set Row that is associated with the Data Set. (Due to its nature, you cannot include a Data Set in a Group Template.)

A benefit of querying a Data Set's table from Crystal Reports, as opposed to standard database tables, is that a Data Set can enable you to query data from multiple database tables without the need for complex cross-tab reports or other formatting. You use expressions to define the content of the cells in the Data Set. In the expressions, you can include tag(s) to refer to properties of database items. You can use the tags to reference different database items, including those in different database tables; likewise, the actual properties that you reference may reside in various database tables. As such, when you query a Data Set's table, each entry in the resulting report or List might include data from a different database table.

A Data Set is a document (as is a Mimic, or a Trend) and as such the settings that you specify using the Data Set's Editor are configuration, rather than data. By changing those settings (known as the Data Set's 'definition'), you change the Data Set's configuration. You use the Data Set to define the fields in the Data Set's table, and Data Set Rows to define individual rows in that table.

As such, the Data Set 'custom' table consists of:

• A Data Set database item that contains the table name and the definition of the table

  and

• Data Set Row database items, one for each row you require. Each row references the Data Set definition.

If your database structure is 'modular' consider using a Group Template to store 'model' Data Set Row configuration. Be aware that you can only add Data Set Rows (rather than Data Sets) to Group Templates.

Operators can use the Display Data pick action to display Data Set data in List format, and can navigate and sort the data in that List.

To create and configure a Data Set, follow this procedure:

1. Add a Data Set to the ClearSCADA database.
2. Configure the Properties on the Data Set Form.
3. Edit a Data Set.

   While the Data Set is displayed in Design Mode, you can perform activities such as:

   • Add, Edit or Delete Fields in a Data Set.
   • Specify the Data Set Field Properties.
4. Save the configuration.

Once you have configured the Data Set, you need to add Data Set Rows and associate them with that Data Set (see Configuring a Data Set Row). You use the Data Set Rows to configure the expressions that define how the fields in the Data Set are populated. You usually place each Data Set Row in a different Group to the Data Set (you typically place the Data Set Row in a Group Template if you want to use the Data Set to collate data for each instance of that Group Template).