Example B.10. Sybase Datasource
<?xml version="1.0" encoding="UTF-8"?> <datasources> <local-tx-datasource> <jndi-name>jdbc/SybaseDB</jndi-name> <!-- Sybase jConnect URL for the database. NOTE: The hostname and port are made up values. The optional database name is provided, as well as some additinal Driver parameters. --> <connection-url>jdbc:sybase:Tds:host.at.some.domain:5000/db_name?JCONNECT_VERSION=6</connection-url> <driver-class>com.sybase.jdbc2.jdbc.SybDataSource</driver-class> <user-name>x</user-name> <password>y</password> <exception-sorter-class-name>org.jboss.resource.adapter.jdbc.vendor.SybaseExceptionSorter</exception-sorter-class-name> <!-- sql to call when connection is created <new-connection-sql>some arbitrary sql</new-connection-sql> --> <!-- sql to call on an existing pooled connection when it is obtained from pool <check-valid-connection-sql>some arbitrary sql</check-valid-connection-sql> --> <!-- corresponding type-mapping in the standardjbosscmp-jdbc.xml (optional) --> <metadata> <type-mapping>Sybase</type-mapping> </metadata> </local-tx-datasource> </datasources>
B.4.1. Sybase Limitations
- DDL statements in transactions
- Hibernate, which is an integral part of the Enterprise Platform, allows the SQL Dialect to decide whether or not the database supports DDL statements within a transaction. Sybase does not override this. the default is to query the JDBC metadata to see whether DDL is allowed within transactions. However, Sybase does not correct report whether it is set up to use this option.Sybase recommends against using DDL statements in transactions, because of locking issues. Review the Sybase documentation for how to enable or disable the
ddl in tranoption.
- Sybase does not throw an exception if a value overflows the constraints of the underlying column.
- Sybase ASE does not throw an exception when Parameterized Sql is in use.
jconn3.jaruses Parameterized Sql for insertion by default, so no exception is thrown if a value overflows the constraints of the underlying column. Since no exception is thrown, Hibernate cannot tell that the insert failed. By using Dynamic Prepare instead of Parameterized SQL, ASE throws an exception. Hibernate can catch this exception and act accordingly.For that reason, set the
Dynamic prepareparameter to
truein Hibernate's configuration file.
jconn4.jaruses Dynamic Prepare by default.
- SchemaExport cannot create stored procedures in chained transaction mode
- On Sybase, SchemaExport cannot be used to create stored procedures while in while in chained transaction mode. The workaround for this case is to add the following code immediately after the definition of the new stored procedure:
<database-object> <create> sp_procxmode paramHandling, 'chained' </create> <drop/> </database-object>