The code generated by LLBLGen contains the oracle schema name in it.

We have a situation where we generated code against schema A in an oracle database, and would like to run a duplicate version of the application against schema B in the same database, A and B being structurally identical. Is there a way to do not embed the schema name in the code and read it from the config file, or better yet, use the user id from the connection string?

You should check "Generated code - Application configuration through .config files" at Help files. You can do something like

<configSections>

    <section name="oracleSchemaNameOverwrites" type="System.Configuration.NameValueSectionHandler" />

</configSections>

...

<oracleSchemaNameOverwrites>
    <add key="SCOTT" value="HR" />
</oracleSchemaNameOverwrites>