Solved

I've got the following exception when I try to run the code below:

Posted on 2011-09-23
7
244 Views
Last Modified: 2012-05-12
Hi Experts,

I've got the following exception when I try to run the code below:
ExecuteReader: CommandText property has not been initialized
The first time it runs without errors, the exception occours when I recall it.

 conn = new SqlConnection(Constants.ConnectionDbSupporto);
                string queryString = "SELECT COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, NUMERIC_PRECISION, NUMERIC_SCALE FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME='" + nomeTab + "'";
                SqlCommand sqlcmd = new SqlCommand(queryString, conn);


                if (conn.State == ConnectionState.Closed)
                    conn.Open();
                sqlcmd.CommandText = queryString;

                sqlDr = sqlcmd.ExecuteReader();
                while (sqlDr.Read())
                {
                    ...                }

                sqlDr.Close();

               
0
Comment
Question by:dionisio_79
  • 4
  • 2
7 Comments
 
LVL 44

Expert Comment

by:AndyAinscow
ID: 36587186
You mean like the following?

SomeFn()
{
conn = new SqlConnection(Constants.ConnectionDbSupporto);
                string queryString = "SELECT COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, NUMERIC_PRECISION, NUMERIC_SCALE FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME='" + nomeTab + "'";
                SqlCommand sqlcmd = new SqlCommand(queryString, conn);


                if (conn.State == ConnectionState.Closed)
                    conn.Open();
                sqlcmd.CommandText = queryString;

                sqlDr = sqlcmd.ExecuteReader();
                while (sqlDr.Read())
                {
                    ...                }

                sqlDr.Close();
}

SomeOtherFn()
{
  SomeFn();  //OK
  SomeFn();  //Now fails with error
}

Open in new window

0
 
LVL 4

Expert Comment

by:theHollow
ID: 36587487
Hello
Try this instead:

SqlCommand sqlcmd = conn.CreateCommand();

:-)
0
 

Author Comment

by:dionisio_79
ID: 36587590
I've tryed with the createcommand method but the result is still the same

The method is called in the ExportForm_load method which is the event handler for the form load event.
this.Load += new EventHandler(ExportForm_Load);

the second time, when I press a button, I recall the load method:

  this.ExportForm_Load(this, new EventArgs());
0
Live: Real-Time Solutions, Start Here

Receive instant 1:1 support from technology experts, using our real-time conversation and whiteboard interface. Your first 5 minutes are always free.

 
LVL 44

Expert Comment

by:AndyAinscow
ID: 36587673
BAD.

Have a function that performs this code.
Call the function from the Load event and from the button event.
0
 
LVL 44

Accepted Solution

by:
AndyAinscow earned 500 total points
ID: 36587688
eg.  (not real code)

SomeFn()
{
.... //your database code goes here
}

FormLoad()
{
SomeFn();
}

ButtonClick()
{
SomeFn();
}
0
 

Author Comment

by:dionisio_79
ID: 36588154
I've changed the code as you suggested but I've got the same result
0
 
LVL 44

Assisted Solution

by:AndyAinscow
AndyAinscow earned 500 total points
ID: 36588673
Please post your now actual code - there is nothing obviously wrong with the code you have posted.  In other words it should work, unless you have edited the problem line out that is.
0

Featured Post

Live: Real-Time Solutions, Start Here

Receive instant 1:1 support from technology experts, using our real-time conversation and whiteboard interface. Your first 5 minutes are always free.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Summary: Persistence is the capability of an application to store the state of objects and recover it when necessary. This article compares the two common types of serialization in aspects of data access, readability, and runtime cost. A ready-to…
This article introduced a TextBox that supports transparent background.   Introduction TextBox is the most widely used control component in GUI design. Most GUI controls do not support transparent background and more or less do not have the…
Microsoft Active Directory, the widely used IT infrastructure, is known for its high risk of credential theft. The best way to test your Active Directory’s vulnerabilities to pass-the-ticket, pass-the-hash, privilege escalation, and malware attacks …
Although Jacob Bernoulli (1654-1705) has been credited as the creator of "Binomial Distribution Table", Gottfried Leibniz (1646-1716) did his dissertation on the subject in 1666; Leibniz you may recall is the co-inventor of "Calculus" and beat Isaac…

785 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question