Question

I have three tables and my requirement is to fetch their records by using the parent record of each table.

So I have three queries. Here is a code sample:

First Query

SQLConnection con = new SQLConnection("connectionstring");

SQLCommand cmd1 = new SQLCommand (1stQuery,con);
SQLDataReader rs1 = cmd1.DataReader();

while (rs1.Read()) {

// Making 2nd Query, 2nd Query is using 1st Query result

SQLCommand cmd2 = new SQLCommand(2ndQuery,con);
SQLDataReader rs2 = cmd2.DataReader();

while (rs2.Read()){

//Making 3rd Query using 2nd Query result
}
}

It gives the error that there is already an open DataReader. I dont want to close the SQL connection and open it for each query, as this is bad for performance.

I want to use only one SQL Connection for all the queries.

Answer 1

I suggest to use ExecuteDataSet. It will contain the result of all three queries. Moveover, These queries should be executed in stored procedure.

Otherwise you are inviting Sql Injections

Sql Injections