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When you register, my team of editors will also send you resources covering Linux administration and management; integration and interoperability between Linux, Windows and Unix; securing Linux and mixed-platform environments; and migrating to Linux.
Margie Semilof, Editorial DirectorIf all the databases exist on the same MySQL server, there is no need to set up anything special. You can query against tables in any database, using dbName.tableName. For example:
SELECT * FROM db1.table1 JOIN db2.table2 ON (table1.id = table2.id);
Check out "SELECT Syntax" and "Identifier Qualifiers" of the MySQL 5.0 Device Manual for more details.
If your databases are on different servers, you can either set up replication so that one server gets an update copy from the other, or you can use the FEDERATED storage engine to define a sort of symbolic link to a remote table.
Chapter 6, "Replication," and the "Federated Storage Engine" sections of the MySQL 5.0 Device Manual can help you with either of those tasks.
This was first published in September 2006