how to make my database layer connect to multiple SQL db

Question

I am using ADO.Net to connect with SQL server, i use my DBLayer to get data from Database and which returns DataTable and Dataset.

 

In Web API i desealize Datatable to JSOn which i got by calling BAL, and bal calls DAL.

 

Now the requirement is my WEb Api request will contain a Code in header, this header value will decide which database connect to.

 

I have a xml file which contains connectionstrings in format 

</dbs> 

   <db code='xyz' value='full connection string'>

   <db code='pqr' value='full connection string'> 

<dbs>

 

this is the code which lives in HTTPREquest header.

 

 

SO the question is am i doing it in right way. or what is the best way to accomplish this task and optimize my code.