JDBC mediator exceptions

The Mediator exception is the root exception of all the data mediator services, and the JDBCMediator exception is the root exception for the JDBC DMS in particular.

The DB exception occurs when an error is reported by the database. This can occur several ways:

• when the connection being used has the AutoCommit property set to true, but the JDBC DMS is controlling the transaction and needs it to be set to false

• when an unsupported database is trying to be used

• when other backend database errors occur during commit or rollback.

An optimistic concurrency control (OCC) exception occurs when the applyChanges() operation results in an data collision. When this occurs, the exception contains the original row values, current row values, and the attempted row values. These values are used to help recover from the error.

An InvalidMetadata exception occurs for invalid metadata supplied to the JDBC DMS upon creation. This can happen when a query requires tables or columns that are not defined in the metadata, or when there are identical column names for different tables for the Oracle, Informix, and older supported versions of Sybase databases.

 

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