"kaobe" wrote : Hi, | | either you define n *-ds.xml files, each defining one database connection, or you use one -ds.xml file that defines the n connections to the database. Inside the datasources tag you can define n datasources. | | Peter thanks for your reply. this is my mysql-ds.xml in the folder of the default deploy. but i don't know how to config standardjbosscmp-jdbc.xml file because in this file there is only one default property "datasource". how to set three databases. standardjbosscmp-jdbc.xml: ..... java:/A <datasource-mapping>mySQL</datasource-mapping> ...... mysql-ds.xml: <local-tx-datasource> <jndi-name>A</jndi-name> <connection-url>jdbc:mysql://localhost:3306/A</connection-url> <driver-class>com.mysql.jdbc.Driver</driver-class> <user-name>root</user-name> </local-tx-datasource> <local-tx-datasource> <jndi-name>B</jndi-name> <connection-url>jdbc:mysql://localhost:3306/B</connection-url> <driver-class>com.mysql.jdbc.Driver</driver-class> <user-name>root</user-name> </local-tx-datasource> <local-tx-datasource> <jndi-name>C</jndi-name> <connection-url>jdbc:mysql://localhost:3306/C</connection-url> <driver-class>com.mysql.jdbc.Driver</driver-class> <user-name>root</user-name> </local-tx-datasource> View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4000252#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...