The following figure illustrates how the interface libraries assemble the list of connection parameters they use to establish a connection.
Key points from the figure include:
Precedence Parameters held in more than one place are subject to the following order of precedence:
That is, 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.