LinkType

The LinkType property determines how two data sources
are joined. The following list describes each option:
• Passive: The query on the joined data source is only
executed when the form is opened. A later change in the
controlling data source does not change the view.
• Delayed: The query on the joined data source is
executed every time that the controlling data source is
changed. The query execution is delayed to avoid the
fetch of data, if the controlling data source is changed
multiple times in a short time. This is the case when the
user is scrolling through data on a grid.
• Active: This option is similar to Delayed, except there is
no delay before the query is executed.
• InnerJoin: Selects records from the main table that have
matching records in the joined table and vice versa. If
the joined table does not have any records related to the
main table record, the main table record is not
displayed. Each match returns a result set of the main
table record and joined table record joined together as
one record. This is useful when wanting to display
records from both tables in a grid.
• OuterJoin: Selects records from the main table whether
they have matching records in the joined table. Each
match returns a result set of the main table record and
joined table record joined together as one record. If
there is no match, the fields from the joined table will be
empty.
• ExistsJoin: Selects a record from the main table only if
there is a matching record in the joined table. As soon as
a matching record is found, the main table record is
returned. The record in the joined table is never
retrieved.
• NotExistsJoin: Select records from the main table that
do not have a match in the joined table.