Welcome to the ClearSCADA Guide to Working with SQL. This guide is designed for use by engineers that have SQL programming experience. This is not a comprehensive guide to SQL, but provides generic information about the use of key aspects of SQL and a technical reference for the SQL features that are supported in ClearSCADA. For more information about SQL, see Implementation of SQL in ClearSCADA.
ClearSCADA uses SQL-92 revision of the SQL standard, with the addition of some custom syntax, which is documented in the relevant sections where it is used.
Intended Audience
This guide is designed to be used by engineers who are responsible for creating SQL queries in ClearSCADA.
Document Scope
This guide provides guidelines for the general use of SQL queries with your ClearSCADA software solution. The most common SQL operation in ClearSCADA is the query that allows you to access and display data from the database. For more information, see the topics that are listed in the gray footer section at the bottom of this topic. Select the relevant entry to display the topic that you require.
SQL queries should be written by engineers who have the appropriate experience and knowledge of the SQL language. Running a badly designed SQL query can have an adverse affect on the system. All queries should include suitable restrictions to limit the number of records that are retrieved from the database. An SQL query that queries vast amounts of data will affect the performance of the server while that query executes.
Further Information
SQL Query and List Problems in the ClearSCADA Guide to the Server Status Tool.
Inefficient SQL Queries in the ClearSCADA Guide to the Server Status Tool.
Avoid using the underscore character ( _ ) in the names of database items: see Naming Restrictions in the ClearSCADA Guide to Core Configuration.