Insert into table from select query + variables values - asp.net

Question

I want to insert into the table tb2 (QuestionID, QuestionStem, UserID, ExamID) a set of rows selected randomly from table tb1 (QuestionID, QuestionStem) along with values for the two columns UserID, ExamID which are fixed for one insert query. I have tried this query in webmatrix, but I got an error that # should not be in this location in the insert query statment:
db.Query("INSERT INTO tb2 (QuestionID, QuestionStem, UserID, ExamID) SELECT QuestionID, QuestionStem, #UserID, #ExamID FROM tb2");
Any help is appreciated. I am using webmatrix 3.0 to build my app.
Note, UPDATE statement after insert will not work as there will be simultaneuos users and I want to present the selected row based on UserID and ExamID per user.

Answer 1

You can't accomplish your task with a single parameterized query in Webmatrix and, in my opinion, it's not a good solution create a query concatenating parameters.
A better alternative could be extract from table t1 the records you need and insert them one by one with a foreach loop:
#{
var userId = 25;
var examId = 32;
var sql1 = "SELECT TOP 10 QuestionID, QuestionStem FROM t1 ORDER BY NEWID()";
var sql2 = #"INSERT INTO tb2 (QuestionID, QuestionStem, UserID, ExamID)
VALUES (#0, #1, #2, #3)";
var db = Database.Open("yourDb");
var data = db.Query(sql1);
foreach (var row in data){
db.Execute(sql2, row.QuestionID, row.QuestionStem, userId, examId);
}
}
Edited
If performances are a real concern, maybe the best solution is to migrate data from Sql Server Compact to Sql Server Express.
In this environment you could create a Stored Procedure like
CREATE PROCEDURE AddQuestions #UserID int, #ExamID int
AS
INSERT INTO dbo.tb2 (QuestionID, QuestionStem, UserID, ExamID)
SELECT TOP 10 QuestionID, QuestionStem, #UserID AS UserID, #ExamID AS ExamID
FROM dbo.t2 ORDER BY NEWID()
GO
and recall it in WebMatrix:
#{
var userId = 14;
var examId = 16;
var db = Database.Open("yourDb");
var data = db.Execute("EXEC AddQuestions #UserID = #0, #ExamID = #1",
userId, examId);
}

Answer 2

If I understand you correctly, you could use numbered ordinals for the two parameters. Something like this, but setting the variables to use your data as appropriate of course:
var userId = 0;
var examId = 0;
db.Query("INSERT INTO tb2 (QuestionID, QuestionStem, UserID, ExamID) SELECT QuestionID, QuestionStem, #0, #1 FROM tb1", userId, examId);
You also mentioned you want the rows from tb1 to be selected randomly. You can achieve this by adding ORDER BY NEWID() to the end of the SELECT statement in your query:
db.Query("INSERT INTO tb2 (QuestionID, QuestionStem, UserID, ExamID) SELECT QuestionID, QuestionStem, #0, #1 FROM tb1 ORDER BY NEWID", userId, examId);
If you want to limit it to a number of rows only you can do (for example, with ten rows):
db.Query("INSERT INTO tb2 (QuestionID, QuestionStem, UserID, ExamID) SELECT TOP 10 QuestionID, QuestionStem, #0, #1 FROM tb1 ORDER BY NEWID", userId, examId);