Outer, Self, and Theta Joins
The preceding sections of this chapter described the equi-join or, in the parlance of SQL-92, an inner join. Inner joins are the most common type of join in database applications. Access also lets you create three other joins: outer, self, and theta. The following sections describe these three less common types of joins.
Creating Outer Joins
Outer joins allow you to display the fields of all records in a table participating in a query, regardless of whether corresponding records exist in the joined table. With Access, you can choose between left and right outer joins.
When diagramming database structures (a subject of Chapter 22, "Exploring Relational Database Design and Implementation"), you traditionally would draw ...
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