How do I retrieve data from multiple database using entity framework

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I am developing an API in C#, using entity framework data model. I am connected to an existing database and can get or post data as i wish too. But now i want to fetch some data which is present in another database and display the information of an employee from two different databases.
Below is the code through which i am retrieving data from a single database.

What I have tried:

public HttpResponseMessage Get(int EmployeeId)
{
  var masterInfo = entities.Empmasters.where(e => e.EmployeeId == 
                                             EmployeeId).FirstOrDefault();

  if (masterInfo == null)
  {
     return Request.CreateErrorResponse(HttpStatusCode.NotFound, "No info");
  }
  else
  {
    return Request.CreateResponse(HttpStatusCode.OK, masterInfo);
  }

Posted 31-Jul-18 20:05pm

Tausif Khan

Updated 31-Jul-18 21:31pm

v2

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Keviniano Gayo · Answer 1 · 2018-07-31T21:32:00

Solution 1

You can create another DBContext and entities for another database.
Or you could create new API project and call its endpoint to get other information.
Or you could create a Stored Procedure that call another database, and call the stored procedure in your current DBContext.

Posted 31-Jul-18 21:32pm

Keviniano Gayo

Comments

Tausif Khan 1-Aug-18 5:24am

@keviniano: Suppose i create another DBContext and entities to connect to my second database, then how do i maintain the connection string throughout the action. For eg: In my case it will be an employee logging in, so some of his information will be retrieved from one database n some from another. Now he tries to apply a leave again in which the record will be saved in the table of my second database. So how do i maintain the same connection string till he manages to log out of the application. Sorry for the long comment.

Keviniano Gayo 1-Aug-18 5:55am

You will setup different connection string for each DBContext.
class EmployeeDB : DBContext
public EmployeeDB() : base("name=employeeConnectionString")

class LeaveDB : DBContext
public LeaveDB() : base("name=leaveConnectionString")

app.config:
<add name="employeeConnectionString"
providerName="System.Data.SqlClient"
connectionString="Server=.\SQLEXPRESS;Database=Blogging;Integrated Security=True;"/>

<add name="leaveConnectionString"
providerName="System.Data.SqlClient"
connectionString="Server=.\SQLEXPRESS;Database=Blogging;Integrated Security=True;"/>