Operation Manual

Understanding Databases
Linking tables
25
502 Crystal Reports User’s Guide
Note: Left Outer and Right Outer joins are handled differently in the SQL
language from other join types. If the database is accessed through ODBC,
Crystal Reports uses ODBC syntax in the SQL statement. If you are
connecting to an SQL database directly (not through ODBC), Crystal Reports
uses a syntax native to the database. For more information about what an
Outer join looks like in an SQL statement, refer to Microsoft ODBC
documentation or to the documentation for your SQL database.
Right Outer join
The result set from a Right Outer join includes all the records in which the
linked field value in both tables is an exact match. It also includes a row for
every record in the lookup (right) table for which the linked field value has no
match in the primary table. If you link the Customer table to the Orders table,
you get one row in the table for each order a customer has placed. You also
get a row for every order found that cannot be linked to a customer.
Theoretically, this should not happen, but if an inexperienced sales person
forgot to assign a customer ID to an order, you can quickly locate that order
with a Right Outer join. The resulting table leaves a blank in any of the
Customer fields for the order without a customer.
58 La Bomba de Bicicleta 1956.20
60 Mountain Toad 24580.50
62 SFB Inc. 7911.80
63 Sierra Bicycle Group 19766.20
63 Sierra Bicycle Group 12763.95
64 Sierra Mountain 8233.50
54 Bicicletas Aztecas
55 Deely MTB Inc.
Customer Table Customer Table Orders Table
Customer ID Customer Name Order Amount
Customer Table Orders Table Orders Table
Customer ID Order ID Order Amount
52 6 25141.50
53 11 19164.30
53 21 1683.60
57 4 15716.40