Different type of Joins and Link Type
Car Table
CarId
|
ModelYear
|
CarBrand
|
Model
|
Mileage
|
ModelYear
|
CarId
|
CA101
|
2008
|
Mahindra
|
Scorpio
|
15
|
2008
|
CA101
|
CA102
|
2009
|
Suzuki
|
800
|
12
|
2009
|
CA102
|
CA103
|
2007
|
Hundai
|
i20
|
5
|
2007
|
CA103
|
CA104
|
2007
|
Toyato
|
Inova
|
3
|
2007
|
CA104
|
CA105
|
2009
|
BMW
|
|
5
|
2009
|
CA105
|
CA106
|
2010
|
Benz
|
AZ12
|
10
|
2010
|
CA106
|
RentalId
|
CustAccount
|
CarId
|
FromDate
|
ToDate
|
ToDate
|
FromDate
|
RE101
|
1104
|
CA101
|
10/12/2010
|
10/29/2010
|
10/29/2010
|
10/12/2010
|
RE102
|
1102
|
CA102
|
11/17/2010
|
12/14/2010
|
12/14/2010
|
11/17/2010
|
RE103
|
1203
|
CA103
|
11/24/2010
|
12/15/2010
|
12/15/2010
|
11/24/2010
|
RE104
|
1301
|
CA104
|
12/10/2010
|
1/5/2011
|
1/5/2011
|
12/10/2010
|
RE105
|
1304
|
CA101
|
1/3/2011
|
1/18/2011
|
1/18/2011
|
1/3/2011
|
RE108
|
1303
|
|
|
|
|
|
RE107
|
1202
|
|
|
|
|
|
RE106
|
2024
|
CA103
|
1/10/2011
|
1/29/2011
|
1/29/2011
|
1/10/2011
|
Select records from main table that have matching record
form join table.
Main table record and join table records are joined together
and show as single record.
Code
static void JoinExamples(Args _args)
{
CarTable
carTable;
RentalTable
rentalTable;
;
while select
carTable join rentalTable
order by
carTable.CarId
where
carTable.CarId == rentalTable.CarId
{
info(strfmt("Car id is %1 renatla id is %2",carTable.CarId,
rentalTable.RentalId));
}
}
Outer Join
Select all the records from main table and related records from join
table
If there is no match, the field from join table is empty
Code
while select carTable outer join rentalTable
order by
carTable.CarId
where carTable.CarId ==
rentalTable.CarId
Output
Exists Join
Selecting record from main
table only if there is matching record in join table.
It shoul be return only main
table record, not a related table record.
Code
while select carTable Exists join rentalTable
order by
carTable.CarId
where carTable.CarId ==
rentalTable.CarId
Output
Not Exists Join
Selecting record from main table only if there is not
matching record in join table.
It is directly irrelevant to the Exists join.
Output
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.
Form Output
Form Design in Data Source Level:
Link Type: Active
The child data source is updated immediately when a new
record in the parent data source is selected. Continuous updates consume lots
of resources.
Link Type: Passive
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.
really great, thanks
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