Joining Tables

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If you want to retrieve data from more than one table, you must define how the related tables are linked. This is achieved by joining fields (columns) between the tables. The linked fields should correspond to each other.  For example the Customer ID field in an Invoice would correspond to the Customer ID field in the Customer table.


You may modify the query inside the Visual Query Builder


Simple Table Joins


To join tables, drag a field in the first table and drop it on the corresponding field in the second table.





Advanced Table Joins


1. Click the Join Link Line to select it. It will highlight.




2. Right Click to access the popup menu and select Join Properties. 3. Select the appropriate Join Type from the dialog box. This allows you to change the default properties of a join




In the Join Properties Window, you can control how the records that do not match are handled. Normally, rows that do not have a matching record in the joined table, are omitted from the resultant dataset. In some cases you may want all the rows from one of the tables, and the corresponding rows in the second table if they are present.
Join Type allows you to change the behavior of your table join. The default setting is "only those records where the two values match". By selecting the second option you are performing the equivalent of an Inner Join, i.e. all records from the First table. The third option is the same as an Outer Join so all records in the right hand table.
Compare Operator. As you change the compare operator the condition is applied to the second and third join types. The first is always an equality comparison. The Inner or Outer join will be satisfied by the condition selected.


See Also:

Adding Tables to Query

Selecting Fields