In the editor graph, creating a new
relationship is somewhat simplified because you select the two business tables on the
canvas, and the Relationship Properties dialog box is pre-populated
with your selections. Before you start, make sure that the model you want to add a
relationship to is selected, and that the business tables are displayed in the editor
graph.
-
Select the two business tables
you want to include in the new relationship, either by clicking and dragging a
marquee around the tables or by holding the
SHIFT
CTRL
keys, then clicking on the tables.
-
Once your business tables are
selected, right-click on the selection. Click Add
Relationship in the popup menu.
-
When the Relationship
Properties dialog box appears, select a business table from the
From Table/Field list.
This is the first relationship.
-
Select a business table from the To Table/Field
list.
This steps sets up a relationship between two
tables.
-
Specify the business columns (from the adjacent lists) from each business table
that identify this relationship. If the business column names are similar, click
Guess Matching Fields and let Pentaho Metadata Editor attempt to determine the columns for you.
-
Define the relationship from the Relationship drop-down
list.
-
Click OK when you are done.
You should see a new relationship line drawn between the
two tables on the editor graph, and the relationship represented in the
navigation pane.
Note: Complex joins appear in
the WHERE clause of the SQL statement, so
currently any joining that takes place in the FROM clause of the SQL statement is not supported. An
example of a complex join might be TABLE_A.COL_A=TABLE_B.COL_A AND
TABLE_A.COL_B=TABLE_B.COL_B. This represents a join of two tables based
on two key columns versus a single join column. Also note, the complex
join expression provided must use the names of the physical tables and
physical columns, not business tables and business column names.