JoinDef Specification Frame--Specify Other Components of the JoinDef
After you complete the JoinDef Definition frame, you can specify other components of the JoinDef—the join columns, the update and delete rules, and the display characteristics. To reach the JoinDef Specification frame, choose the Joins operation.
The JoinDef Join Specification frame includes a list at the top of the frame that details existing joins, a table field for displaying information about table column names, and a menu of operations.
You can use the JoinDef Join Specification frame to change Join columns.
For example, in a JoinDef containing the tables Staff and Tasks, QBF selects the column called Name in each table as the join column. If there are no common columns with the same name, the JoinDef Join Specification frame is displayed empty, and you must enter the join columns you wish to use.
Rules
Establishes rules for deleting or updating data in the tables included in the JoinDef.
GetTablDef
Gets information on columns in a table.
ListChoices
Lists the available choices for the selected field.
Cancel
Cancels any changes made to the join specification and returns to the JoinDef Definition frame.
Help, End
Perform standard operations.
View or Change Joined Columns
In the following figure, the Name column in the Staff table is the join column with the Manager column of the Manager table. The MM between the two-table/column names indicates that this is a Master/Master join.
The table fields at the top of the JoinDef Join Specification frame are as follows:
Column
Contains the column name of join column(s) in the table. Column name format: abbreviation.columnname, where abbreviation is the abbreviation of the table name and columnname is the column name. In the above figure, the column name m.manager means the name column from the Manager table. The column on the left is joined to the column on the right.
Join
Indicates whether the join is Master/Master (MM), Master/Detail (MD), or Detail/Detail (D/D).
Column
Contains the column name of join column(s) in the second table. Column name format is the same as for the first column. In the above figure, the column name s.name means the name column from the Staff table.
You can add, delete, or change join specifications by editing the table field at the top of the frame. If you alter the join specification, make sure that the two join columns in each table are of the same data type.
Get Information on Table Column Data Types
To display a list of a table's columns and column formats, enter the name (or abbreviation) of the table and select the GetTableDef operation. That table's columns and their data types are then displayed, as shown in the following figure.
Exit the JoinDef Join Specification Frame
When you exit the JoinDef Join Specification frame by selecting Rules or End, QBF checks the validity of your entries and reports any errors it finds. If the join information is valid, you exit the frame. If it is not valid, QBF displays an error message that indicates the problem and returns you to the frame so that you can correct it:
• Select Rules to set rules for modifying the tables in your JoinDef. For more information, see Update and Delete Rules.
• Select the End operation to return to the JoinDef Definition frame.
• Select the Cancel operation to cancel any changes made to the JoinDef Join Specification frame and return to the JoinDef Definition frame.
Last modified date: 08/28/2024