Supported SQL Syntax

The OLE DB provider supports the SET and SELECT statements in SQL queries. The following conditions apply for the supported SQL syntax:

• The supported statements follow the standard SQL-92 conventions.
• Adhering to SQL standards, these statements are not case-sensitive.
• The OLE DB provider does not allow SQL inserts, updates, deletes, or commits; therefore, there is no event notification. You can only retrieve and analyze data.
• String data types are not supported.

Some reporting packages, such as Crystal Reports, hide the SQL syntax by allowing you to use experts and wizards. However, familiarity with SQL syntax may help you in troubleshooting and tuning your SQL commands.

The following figure shows a SELECT statement. With a SELECT statement, you can specify the Historian table and columns from which you want to retrieve data. The OLE DB provider establishes the server name at connection time. You can filter the data returned from SELECT by specifying a filter option in the WHERE clause.