Queries — finding data from multiple tables

Summary

Queries in multi-table databases are even more flexible than they are in single table databases because you can ‘mix and match’ data from the various tables to reach precisely the information you want. All the different types of queries covered in Chapter 9 (range, update, crosstab and so on) are, of course, still available to you.

A query can either take all the records that have matching records in the tables to which they are joined or, using outer joins, you can insist that all records from a specific table are included in the answer table. Queries can be based on one table, all tables or a subset of tables and, by recycling an existing query as the basis for another, you can work even more efficiently.

The queries described above are to be found in the chap17end.mdb file.