Table Joins
Create table joins in business views to access data from multiple tables in a single application.
You typically use table joins for forms that are not input-capable, such as find browse forms, and reports. You do not usually use joins for forms that update and add to the database. When you are updating the database, the relationship between the records must be precise. If you must use a table join for an input-capable form, only use a join where the relationship between the two tables is simple.
If a business view uses multiple tables, link the tables by establishing joins between columns in those tables. The links define how rows from one table correspond to rows in another table.
When you join a column in one table to a column in another table, both columns must be of the same data type. You can use the Object Properties form to view attributes for a column to determine whether you can use it in a join. The Object Properties form displays the attributes of the data item that you have highlighted on the Selected Columns form.
Review each table and determine how the data in one table is related to the data in the other tables. You might need to add columns or build new indices in a table, or even create new tables. If you build new indices, consider your business needs carefully before you do so.
Fifteen tables if all joins are simple joins.
Fifteen tables if any of the joins is an outer join or in the event of a table union.
To join columns in a table join business view, use the mouse cursor to draw a line from a column in the primary table to the associated column in a secondary table. When you click the line that you drew, you can define the join by selecting a join type and an operator from the Join menu. These menu options are not available until you have clicked the line joining the columns.
The default join type is simple, and the default operator is equal. Available operators are:
Equal (=)
Not Equal (<>)
Less than (<)
Greater than (>)
Less than or equal (< =)
Greater than or equal (> =)