如何使用Oracle DB在Spring / mybatis应用程序中设置默认架构？

Question

Coming from a mysql background, I am able to set the default schema name that I want to use for all my sql queries in the connection url. I now have an Oracle DB that I need to access. I am aware that I cannot specify the schema I want to use in the URL since the user is the schema name being used.

I realize that I can use a line of SQL code:

ALTER SESSION SET CURRENT_SCHEMA=default_schema

The project is using mybatis 2.3.5 as my SQL framework, but I am completely new to mybatis. Is there a simple way to configure mybatis to accomplish this? My application is a Spring 3 application, so I am using the Spring DataSourceTransactionManager to manage my transactions. I would presume that the manager must be made aware of this requirement to ensure that the command is sent whenever creating a new connection.

I've tried searching online, but most of the examples I find all have the schema names included within the sql queries in the SqlMaps, which I find to be bad practice.

In an ideal world, the schema name would be part of the URL such that I can make changes to the schema name for different environments (ex: dev, test, prod, etc) without touching the code (ie: only configured at the JNDI/application server level). I would be happy if I could use a Spring configuration value to set this as well as I could still use a JNDI lookup or a system environment property to retrieve the value.

Can anyone point me in the right direction?

Thanks,

Eric

Answer 1

As far as I know, there is no option in Oracle to change your URL in order to connect to a specific user schema.

1) mybatis: You may set your current schema to a deserved one before you start your operations. You can write your specification in a property file and set your method's arguments from that file. You do not need to change your code to change your schema in that case.

<update id="mySetSchemaMethod" parameterClass="String">
ALTER SESSION SET CURRENT_SCHEMA = ${schemaName}
</update>

2) trigger: If you are using this connection only for this particular java application, you can set a client event trigger so set your CURRENT_SCHEMA. This time, you need to change the trigger in order to manage test/prod changes.

CREATE OR REPLACE TRIGGER Set_Schema_On_Logon
  AFTER LOGON  
  ON MY_SCHEMA  
BEGIN  
  ALTER SESSION SET CURRENT_SCHEMA = MY_TEST_SCHEMA;  
END;