Use a session's FindDatabase method to determine whether a specified database component is already associated with a session. FindDatabase takes one parameter, the name of the database to search for. This name is a BDE alias or database component name. For Paradox or dBASE, it can also be a fully-qualified path name.
FindDatabase returns the database component if it finds a match. Otherwise it returns nil.
The following code searches the default session for a database component using the DBDEMOS alias, and if it is not found, creates one and opens it:
var DB: TDatabase; begin DB := Session.FindDatabase('DBDEMOS'); if (DB = nil) then { database doesn't exist for session so,} DB := Session.OpenDatabase('DBDEMOS'); { create and open it} if Assigned(DB) and DB.Connected then begin DB.StartTransaction; ... end; end;
TDatabase *DB = Session->FindDatabase("BCDEMOS"); if ( !DB ) // Database does not exist for session so DB = Session->OpenDatabase("BCDEMOS"); // create and open it if (DB && DB->Connected) { if (!DB->InTransaction) { DB->StartTransaction(); . . . } }
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