How to bulk insert in Entity Framework v4?

Question

I have been searching for a solution all day but couldn't find any so here I am, looking for some help.

I have three tables for saving groups & their contacts in my database. For simplicity sake, consider their name as table_1, table_2 & table_3

table_1 (Group Table)

+----------+------+
| Group_Id | Name |
+----------+------+
|        1 | A    |
|        2 | B    |
|        3 | C    |
+----------+------+

table_2 (Contact Table):

+------------+-------+--------+
| Contact_Id | name  | number |
+------------+-------+--------+
|          1 | Jack  |    123 |
|          2 | Sam   |    456 |
|          3 | Alice |    789 |
+------------+-------+--------+

table_3 (Junction Table)

+-----------------+----------+------------+
| ContactGroup_Id | Group_Id | Contact_Id |
+-----------------+----------+------------+
|               1 |        1 |          1 |
|               2 |        2 |          2 |
|               3 |        2 |          3 |
+-----------------+----------+------------+

Now I am reading excel file in my web application and then adding bulk contacts to database. Using EF4, this is what I am trying to do :

using (TransactionScope obj = new TransactionScope(TransactionScopeOption.Required, new TransactionOptions { IsolationLevel = System.Transactions.IsolationLevel.ReadUncommitted, Timeout = TransactionManager.MaximumTimeout }))
{
  for (int i = 1; i < totalrows; i++)
   {
    table_2 objTable_2 = new table_2();
    objTable_2.name = "ABC";
    objTable_2.number= "999";
    entity.table_2.AddObject(objTable_2);
    entity.SaveChanges();

    table_3 objTable_3 = new table_3();
    objTable_3.Group_Id = "1";
    objTable_3.Contact_Id = objTable_2.Contact_Id;
    entity.table_3.AddObject(objTable_3);
    entity.SaveChanges();
   }
}

Now as you can see I have to call entity.SaveChanges() every time to get the auto-generated PK of table_2 to insert in table_3 . Doing this for hundreds or thousands of records is really slowing my application and I know this is a bad way of doing this.

Is there any other work around for this ? if I do this using any third-party bulk-insert extension or calling SaveChanges() after every couple of hundred records then how do I get auto-generated PK for table_2 to insert in table_3 ?

Answer 1

Have a look at this extension for Entity Framework, which is compatible with EF from version 4.x to 6.x.

I've used it a couple of times, and its works pretty well.

Edit:

Solving the PK issue by iserting items within a stored procedure , doing all inserts from it in one call, to avoid thousands of round-trips between .NET code handling inserts and SQL Server