Changing Join Types

Arcadia Enterprise supports four basic types of column connections, otherwise known as joins: inner, left, right, and outer joins.

Developer Notes:The types of joins available depend on the underlying database. For example:

MySQL connections do not support FULL OUTER JOIN operations.
SQLite connections do not support FULL OUTER JOIN and RIGHT OUTER JOIN operations.

Briefly, here are the descriptions of the four join types:

In an inner join, the most common type, rows in the result set contain the requested columns from the both tables for all combinations of rows where the selected columns of the tables have identical values.
In a left join, the result set contains all rows from the left-hand table, and the matching data from the right table. Whenever no matching data is available on the right side of the join, the corresponding columns in the result set have the value NULL.
In a right join, the result set contains all rows from the right-hand table, and the matching data from the left table. Whenever no matching data is available on the left side of the join, the corresponding columns in the result set have the value NULL.
An outer join returns all rows from both tables. Whenever no matching data is available on one of the sides of the join, the corresponding columns in the result set have the value NULL.
A special case, left outer join, supports join elimination in datasets that contain more than one table. By default, this setting is on, but it can be disabled. See Join Elimination.

Consider. By default, Arcadia Enterprise produces left-hand joins.

The following steps demonstrate how to change the join type.

On the Data Data Model page, click Edit Table Links to edit the data model.

Edit Table Links
Click the icon (link) that represents the connection that must be changed.

Editing Table Joins
The Column Connection modal window appears.
In the Column Connection modal window, select an alternate join type.

For example, instead of the default Left join, select Right join.

Changing Join Type from Left Join to Right Join
Click outside the Column Connection modal window.
Click Save.