Question

I am updating a database with a new registered user. they will then be given a userid. I want to use that number when updating there location in another table. but i dont know what the user id will be. (it is autoincrement number) So i was thinkning i would update the first table. And then select the maximum user id and insert that id as the location user id in the other table but I cant get it to work.

Here is the code.

String StrSQL = "INSERT INTO Fastelejer (Fornavn,Efternavn) VALUES ('" + fornavn + "','" +      
Efternavn +  "')";
OleDbCommand InsertCommand = new OleDbCommand(StrSQL, conn);
InsertCommand.ExecuteNonQuery(); 
StrSQL = "INSERT INTO Bådpladser (Fastelejerid) SELECT MAX (Fastelejerid) FROM    
StrSQL = "INSERT INTO Bådpladser (Fastelejerid) SELECT MAX (Fastelejerid)FROM
Fastelejer WHERE Pladsnummer = " + Pladsnummer;

The pladsnummer represents the input for their location. So the registration should put the user id into the location that is chosen.

Answer 1

In MS Access, “autoincrement” is usually called “identity”. You can use the special @@IDENTITY variable to retrieve the ID of the last inserted identity column. Once you know the new ID, you can add it as a parameter in the second insert, like:

command.CommandText = "INSERT Table1 (...) values (...); SELECT @@IDENTITY";
var identity = (int) command.ExecuteScalar();
command.CommandText = "INSERT Table2 (user_id, ...) VALUES (@user_id, ...)";
command.Parameters.AddWithValue("@user_id", identity);
command.ExecuteNonQuery();