Merging two tables in sqlite from different database

Question

I need to merge two tables in sqlite based on a common column. The problem is both the tables belong to different databases. So, what would be an efficient way to merge the tables here?

A sample table would be like this with the desired result. But the problem is these two tables are in different databases.

Table 1: Employee_Pro_Profile
Columns: Emp_Id, Emp_Name, Emp_Sal

Table 2: Employee_Personal_Profile
Columns: Emp_Id, Emp_Home_Address, Emp_Phone

Resulting Table: Employee_Complete
Columns: Emp_Id, Emp_Name, Emp_Sal, Emp_Home_Address, Emp_Phone

Answer 1

Okey first you have to attach the databases, to your current connection.

SQLite give you this by using ATTACH.

The ATTACH DATABASE statement adds another database file to the current database connection. ATTACH LINK

Run this:

attach database DatabaseA.db as DbA;
attach database DatabaseB.db as DbB;

Now you can reference the databases as you do with tables...

select
  *
from
  DbA.Table1 A
  inner join 
  DbB.Table2 B on B.Emp_Id = A.Emp_Id;

There is a limit to the number of databases that can be simultaneously attached to a single database connection.

检查您的设置是否出了问题，标志是：

#define SQLITE_LIMIT_ATTACHED                  7
// SQLITE_LIMIT_ATTACHED - The maximum number of attached databases.