CODEWITHSUNDEEP
c#sql
ThElitEyeS
ThElitEyeS

Reputation: 647

C# Using 2 sqldatareader at same time?

Hello is there a way to use two sqldatareader at same time ?

i was coding a program

and i got error because i use 2 readers at same

Sample of code

SqlCommand LoadSilk = new SqlCommand("SELECT silk_own FROM SK_Silk WHERE JID = (SELECT JID FROM TB_User WHERE StrUserID = '"+ comboBox1.Text +"')", Connection);
SqlDataReader SilkReader = LoadSilk.ExecuteReader();
SqlCommand LoadCharacter = new SqlCommand("SELECT * FROM SRO_VT_SHARD.DBO._Char WHERE CharID IN (SELECT CharID FROM SRO_VT_SHARD.DBO._User WHERE UserJID = "+ JID +")", Connection);
SqlDataReader CharacterReader = LoadCharacter.ExecuteReader();

try
{
    SilkReader.Read();
    textBox5.Text = SilkReader[0].ToString();
    Silk = SilkReader[0].ToString();
    dataGridView1.Enabled = true;
    button2.Enabled = true;
    while (CharacterReader.Read()) {
        dataGridView1.Rows.Add(CharacterReader["CharID"].ToString(), CharacterReader["CharName16"].ToString(), CharacterReader["CurLevel"].ToString());
    }
    log(comboBox1.Text + " account data loaded");
}
catch (Exception ex) {
    log(ex.Message);
    MessageBox.Show("Error");
} finally {
    SilkReader.Close();
    CharacterReader.Close();
}

and its gave me that error

There is already an open DataReader associated with this Command which must be closed first.

Upvotes: 5

Views: 16296

Answers (5)

Wajid khan
Wajid khan

Reputation: 872

1.Just add MultipleActiveResultSets=True into your connection string:

private string _ConnectionString = @"Data Source=(LocalDB)\v11.0;AttachDbFilename=yourdbpath\Database.mdf;Integrated Security=True;MultipleActiveResultSets=True;Connect Timeout=30";

Upvotes: 1

Eduard Boboc
Eduard Boboc

Reputation: 1

Declare those DataReader in the block public partial class Form1 : Form Example: 

namespace GoodFood_1_
{
    public partial class Autentificare_client : Form
   {
        SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Users\edi_b\Documents\visual studio 2013\Projects\GoodFood(1)\GoodFood(1)\GOOD_FOOD.mdf;
        Integrated Security=True;MultipleActiveResultSets=True");
        SqlConnection con2 = new SqlConnection(@"Data Source=(LocalDB)\v11.0;AttachDbFilename=c:\users\edi_b\documents\visual studio 2013\Projects\GoodFood(1)\GoodFood(1)\GOOD_FOOD.mdf;
        Integrated Security=True;MultipleActiveResultSets=True");

        SqlDataReader dr;
        SqlDataReader cc;

        public Autentificare_client()
        {
            InitializeComponent();
        }

Upvotes: 0

Mithrandir
Mithrandir

Reputation: 25397

The error message is misleading. You must have MultipleActiveResultSets=True set in your connection string to be able to send two seperate commands with two different readers.

Upvotes: 14

Sergei Rogovtcev
Sergei Rogovtcev

Reputation: 5832

You'll have to enable Multiple Active Recordsets (MARS) on your connection.

http://msdn.microsoft.com/en-us/library/h32h3abf%28v=vs.80%29.aspx

Upvotes: 3

Nikola Anusev
Nikola Anusev

Reputation: 7088

It is possible when you use something called Multiple Active Result Sets, or MARS. Check out this helpful article that details all possible pitfalls.

Upvotes: 5

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