Microsoft Access 2010 Bible

Part I: Access Building Blocks

162

FIGURE 4.25

An ad hoc join between tblProducts and tblCategories

Auto-join Ad-hoc join

Specifying the type of join

The problem with most joins is that, by default, they exhibit equi-join behavior as the query exe-

cutes. In the case of the query in Figure 4.25, if a product record exists that doesn’t have an

assigned category (for example, a car that was never assigned to a category), the query doesn’t

return any records where a product record is not matched by a category. Figure 4.26 shows the

result of this query.

FIGURE 4.26

You can’t tell that records are missing from this query.