Assembling a list of connection parameters

The following diagram illustrates how the interface library assembles the list of connection parameters and establishes a connection.

Interface libraries assembling a list of connection parameters.
  • Precedence   Parameters held in more than one place are subject to the following order of precedence:

    1. Connection string

    2. SQLCONNECT

    3. Data source

    If a parameter is supplied both in a data source and in a connection string, the connection string value overrides the data source value.

  • Failure   Failure at this stage occurs only if you specify in the connection string or in SQLCONNECT a data source that does not exist.

  • Common parameters   Depending on other connections already in use, some connection parameters may be ignored, including:

    • AutoStop   Ignored if the database is already loaded.

    • DatabaseFile   Ignored if DatabaseName is specified and a database with this name is already running.

The interface library uses the completed list of connection parameters to attempt to connect.