JDBC error messages

JDBC error messages are typically generated by the JDBC driver and the content of such messages depends on the driver that you are using.

The following table describes the typical Java™ ClassNotFound exception and the three main types of JDBC errors. Consult your JDBC driver documentation for specific information about the error messages it generates.

Table 1. JDBC error messages
Error	Description	Action
`java.lang.ClassNotFound Exception: driver class`	The JDBC driver class cannot be found.	Verify that the JDBC driver class name is correct and that the driver .jar files and any dependencies have been installed to the $OMNIHOME/gates/java directory.
Any exception thrown by the `GWJdbcNullPrepared Statement` class. Usually containing the following error message: `java.sql.SQLException: Simulated transaction error`.	This indicates that the Gate.Jdbc.Driver property is empty and the gateway in using an internal test JDBC driver to discard data and simulate errors.	Correctly configuring the Gate.Jdbc.Driver property with the correct driver class name.
JDBC authentication errors	Authentication errors are usually caused by incorrect or invalid user names or passwords.	Verify that you are using correct and valid user names and passwords for the Gate.Jdbc.Username and Gate.Jdbc.Password properties, and wherever else authentication is required.
JDBC connection errors	Connection errors are typically caused by incorrect or invalid connection string parameters, such as an invalid host name or database name.	Verify that you are using correct and valid connection string parameters for the Gate.Jdbc.Url property.
JDBC runtime errors	Runtime errors have various causes. A typical error of this type is a constraint violation. These usually occur when the gateway is performing the initial resynchronization.	Check the exception text for the cause of the error. Constraint violations indicate that the gateway is trying to insert duplicate data into the database. Because the data is already in the database, this is not a problem. If the cause of the problem is not clear from the error message, contact IBM® Software Support.