Related Ado.net For MySql

Question

Hi i have just shifted from ADODB to Ado.net for MySql. I am new to this system.

After going thru the forums i have defined the connection, adapter, reader , command.

I defined in all this in a class, i am calling that class in every form so that i dont have to created the same for every form. I have written things like following

public MySqlConnection conn;
public MySqlCommand cmd;
public MySqlDataReader dr;
public MySqlDataAdapter da;

the DB is conneced through DSN. Here everything is working fine. But while working i got error message like

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

So i searched on forum, but i being new to this things , i request you to please kindly suggest how i can close connect, open connected and how i should declear variables in a class.

I will be very thankful for this in advance. i am developing a customized software , so asap help is very much appriciated.

Thank you

Ankit Sharma · Answer

Hi Kedar Make sure you have used reader.Close(); reader.Dispose(); connection.Close(); at the end of you method https://www.codeproject.com/Questions/616154/There-is-already-an-open-DataReader-associated-wit you can get a sample code here also https://www.aspsnippets.com/Articles/Using-MySQL-database-in-ASPNet-Tutorial-with-example.aspx

kedar pawgi · Answer

Hi Gautam and Ankit...Actually i figured it out. I was not closing the reader  i was just closing the connection. When i properly checked and opened and closed the connected as suggest by Ankit like reader.Close(); reader.Dispose(); connection.Close(); then i re opened the connection. It worked perfectly. Actually both of u given correct ans but i m sorry i will have to accept one answer so i am accepted Ankits ans sorry Gautam for this. Thanks u guys made my day. TC thanks

Ankit Sharma · Answer

Hi kedar i think your issue is similar to one mentioned here https://stackoverflow.com/questions/18475195/error-there-is-already-an-open-datareader-associated-with-this-command-which-mu

kedar pawgi · Answer

Thanks for your reply Gautam and Ankit. Actually my issue is i have totally 3 form out of which i doing operation of INSERT in two form and One of Select. But on 3rd form  i am doing 2 opetations of SELECT i would like to know  does it is giving that error as i am doing two SELECT operations. On first two form its working perfectly. So please let me know how i use c.dr for two different SELECT statements.

Gautam Parmar · Answer

Once you finish use of DataReader close command with below code. SqlDataReader sdr = cmd.ExecuteReader(); //Your Code of Use Data Reader //Close Data Reader sdr.Close();