Change Oracle Schema at runtime when using SubSonic

Question

In my project, I am using Oracle Database and SubSonic for DAL. I have a problem with SubSonic and Oracle Schema, that is:

When developing, I used a schema DEV in Oracle Database and generate DAL using SubSonic. After that when release to customer, he used a new schema TEST in Oracle Database and changed the connection string in app.config to connect to Oracle. The error will appear, that is “Table or View does not exist”. I found this error and see that the schema of tables is still DEV. I do not want re-generate DAL after change schema and when released to the customer. Please help me.

Answer 1

Firstly, your schema should not be DEV. DEV is a user or role. Your schema name should be related to the data content (eg ACCOUNTS or SALES)

Secondly, consider whether you or the customer is going to decide the schema name. Say you have a product called FLINTSTONE. You may decide that the schema name should be FLINTSTONE. However your customer may want to run two instances of your product (eg one for local sales, the other for international) and use the same database. So they want FS_LOCAL and FS_INTER as the schema names. Is that option a feature of your product ?

Next, decide if your application should connect as the schema owner. There are good security reasons for NOT doing that. For example, the schema owner has privileges to drop tables, which is generally something the application doesn't do and thus, on the principle of least privilege, is something your application shouldn't have privileges to do.

Generally I would recommend some config parameter for the application for the schema name, and after connecting to the database, the app should do an "ALTER SESSION SET CURRENT_SCHEMA = 'whatever was it the config file'". The application database user would need the appropriate insert/update/delete/select/execute privileges on the objects in the application schema. If the application can't do that, you can have a LOGON trigger in the database.

Answer 2

Gary is correct in not using DEV as a schema on your own machine. In using Oracle we typically set up the schema as what the client is going to name their schema. This however does not fix your issue. What you need to do is create a global alias in Oracle that maps say DEV to CLIENTSCHEMA. You should still rename the schema on your machine but this will allow your schema to differ from your clients.