You can produce a report that queries a historic table in a similar way to other reports.
With such a report, you typically reference one of the following:
- A ‘custom’ Historic View
- The historic table, CDBHistoric
- The Event Journal table, CDBEventJournal.
In addition, you can reference table(s) that contain the database items that are of interest—for example:
- The Points table, CDBPoint
- The advanced drivers’ points table, CAdvPoint
- The simple drivers’ points table, CSimplePoint
- A driver-specific table.
Where a report references more than one database table, you need to specify the links between those tables (see Specify the Links Between Multiple Tables).
(To include data from unrelated tables, consider whether to Use a Subreport to Include Unrelated Data in the Same Report, a ClearSCADA Data Grid, or a ClearSCADA Data Table (see Custom Tables and Fields).)
With a report that queries a historic table, you have to restrict the amount of data that the report can retrieve from the server. You should include such a restriction as soon as you create the report and certainly before you attempt to preview the report, refresh the report data, or otherwise generate the report. For information, see Restrict the Amount of Data that is Queried in a Report.
Further Information
Working with ClearSCADA Database Tables.
Other historic tables that you might want your reports to reference: see Other Tables in the ClearSCADA Guide to the Database.