Connecting to a Database Server
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There are two ways to connect to a database server using a database component:
- Call the
Open
method. - Set the
Connected
property toTrue
.
Setting Connected
to True
executes the Open
method. Open
verifies that the database specified by the Database
or Directory
properties exists, and if an OnLogin
event exists for the database component, it is executed. Otherwise, the default Login dialog box appears.
Note:
When a database component is not connected to a server and an application attempts to open a dataset associated with the database component, the database component’s
When a database component is not connected to a server and an application attempts to open a dataset associated with the database component, the database component’s
Open
method is first called to establish the connection. If the dataset is not associated with an existing database component, a temporary database component is created and used to establish the connection.Once a database connection is established the connection is maintained as long as there is at least one active dataset. If a dataset is later opened which uses the database, the connection must be reestablished and initialized. An event notifier procedure can be constructed to indicate whenever a connection to the database is made or broken.