Link Type:-
1.
Active: - Parent and child- data source is updated immediately when a new record in the
parent data source is selected. Continuous updates consume lots of resources consuming.
2. Delayed: - Parent and child - A pause is inserted before linked child data sources are updated.
This enables faster navigation in the
parent data source because the records from child data sources are not updated
immediately. For example, you can scroll a list of orders where you do not want
to review the lines associated with the order until you stop scrolling.
3. Passive: - Parent and child - Linked
child data sources are not updated automatically. Updates of the child data
source must be programmed on the active method of the master
data source.
Join Types:-
1. InnerJoin:
- Combined data source – select
the record from the main table that matches records in the joined table and
vice versa.
There
is one record for each match. Records without related records in the other data
source are eliminated from the result.
2. Outer Join: - Combined data source – select the
records from the main table. The records are retrieved whether they have
matching records in the joined table
3. Exist Join: - Combined data source -The data source
retrieves a record from the main table for each matching record in the joined
table.
The
differences between InnerJoin and ExistJoin are as follows:
·
When the join type is ExistJoin, the search ends after the first match has
been found.
·
When the join type is InnerJoin, all matching records are searched for.
4. NotExistJoin: - Combined data source -Select
records from the main table that do not have a match in the joined table.
For more information:-
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