Cannot assign ... Since it is a using variable please advise

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In this code im getting Error in the blocked line. Please advise how to go about it.

C#

mconn.Open();
using (SqlCommand msqlcmd = new SqlCommand("select * from table1", dlsmain.dlsconn))
{
    using (SqlDataReader msqldat = msqlcmd.ExecuteReader())
    {
        msqldat.Read();
		//...  
		//... assignments from msqldat
		//...
        msqldat.Close();
        msqlcmd.CommandText = "select * from table2";
        msqldat = msqlcmd.ExecuteReader();		// Error : Cannot assign to msqldat because it is a 'using variable'.
        while (msqldat.Read())
        {
			//...
			//...  Some process using msqldat
			//...
        }
        msqldat.Close();
        msqlcmd.CommandText = "select * from table3";
        msqldat = msqlcmd.ExecuteReader();
        while (msqldat.Read())
        {
			//...
			//... Some process using msqldat
			//...
        }
    }
}
mconn.Close();

What I have tried:

googled for the error but not got right channel.

Posted 2-Aug-16 20:17pm

Priya-Kiko

Updated 2-Aug-16 20:58pm

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3 solutions

Solution 1

The message is clear enough. You have declared (and assigned a reference to) msqldat in your using statement, which means that it is effectively read-only inside the block. If you allocated some other value to it then it would be compromised and could not properly dispose the original reference.

Posted 2-Aug-16 20:48pm

Richard MacCutchan

Comments

Priya-Kiko 3-Aug-16 2:51am

Thank you, So it is that I have to close the using block after msqldat.Close and then again open another using block for the next set of statements ?

Richard MacCutchan 3-Aug-16 3:05am

Possibly, but that would not necessarily make sense. You need to look at exactly what you are trying to do and adjust your code logically.

Priya-Kiko 3-Aug-16 3:33am

Thank you.

Solution 3

C#

You can't change reference once you used in using clause. I don't thing you require using there, its dis-connected.

Posted 2-Aug-16 20:58pm

The Praveen Singh

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Suvendu Shekhar Giri · Accepted Answer · 2016-08-02T20:53:00

Try following-

C#

using (SqlDataReader msqldat = msqlcmd.ExecuteReader())
{
        msqldat.Read();
	//...  
	//... assignments from msqldat
	//...
        //msqldat.Close();
} 
msqlcmd.CommandText = "select * from table2"; 
using (SqlDataReader msqldat = msqlcmd.ExecuteReader())
{
        msqldat = msqlcmd.ExecuteReader();		// Error : Cannot assign to msqldat because it is a 'using variable'.
        while (msqldat.Read())
        {
			//...
			//...  Some process using msqldat
			//...
        }
        //msqldat.Close();
}
msqlcmd.CommandText = "select * from table3";
using (SqlDataReader msqldat = msqlcmd.ExecuteReader())
{        
        msqldat = msqlcmd.ExecuteReader();
        while (msqldat.Read())
        {
			//...
			//... Some process using msqldat
			//...
        }
}

Hope, it helps :)