Checking SqlConnection.State before opening or closing

Question

5.00/5 (1 vote)

See more:

Is it necessary to check a SqlConnection's state before opening or closing it? That is, is it necessary to do this:

C#

SqlConnection myConn = new SqlConnection(myConnString);
try
{
    SqlCommand myCmd = new SqlCommand(myCmdText, myConn);
    if (myConn.State != ConnectionState.Open)
        myConn.Open();
    myCmd.ExecuteNonQuery();
}
finally
{
    if (myConn.State != ConnectionState.Closed)
        myConn.Close();
}

or can I just call Open, Execute, Close? My boss thinks it's a best practice to check it before it is opened, I think it adds unnecessary code because it would be better to have only one Execute statement per try block.

Posted 13-Apr-12 5:22am

Matt Maynard

Add a Solution

5 solutions

Solution 5

I agree with others that it is not necessary to check before opening connection. But, I suggest that it is mandatory to check connection state before closing connection.

Posted 27-May-13 5:42am

kj.balamurugan

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

ZurdoDev · Accepted Answer · 2012-04-13T05:30:00

Solution 1

Unless I am missing something obvious, no, you do not need to check the state because you just created it with new(). Now, if you were using a common class and were uncertain of the state, then yes it would be a good idea.

Posted 13-Apr-12 5:30am

ZurdoDev

Comments

VJ Reddy 13-Apr-12 12:12pm

Good answer. 5!

Reza Ahmadi · Accepted Answer · 2012-04-13T05:34:00

Solution 2

Hi,
You must open a connection before using it and you should close a connection after running a query. However, in the above code you do not need to check the status of the connection :

C#

if (myConn.State != ConnectionState.Open)

as you know it is closed, so just write:

C#

myConn.Open();

Cheers

Posted 13-Apr-12 5:34am

Reza Ahmadi

Comments

VJ Reddy 13-Apr-12 12:12pm

Good answer. 5!

Reza Ahmadi 13-Apr-12 12:19pm

Thanks

Matt Maynard · Accepted Answer · 2012-04-13T05:37:00

Solution 3

I always create a new connection just before the try statement, but there might be places in our code where a connection is reused multiple times. That being said, checking the state before opening or closing it will (sometimes) prevent InvalidOperationException from throwing, so it could be useful for that reason.

Posted 13-Apr-12 5:37am

Matt Maynard

Comments

VJ Reddy 13-Apr-12 12:28pm

Good answer. 5!

VJ Reddy · Accepted Answer · 2012-04-13T05:43:00

As Reza Ahmadi said in Solution 2, it is necessary to open connection, before it is used. But SqlConnection.Open Method will throw InvalidOperationException if the connection is already open as explained here.
SqlConnection.Open Method[^]
So if you are not sure about the current state of the connection, then I think it is better idea to check state to avoid throwing an exception.
As ryanb31 said in Solution 1 for the situation given in the question, it is not necessary to check whether connection is open, as the connection is created just above.
But, I think using block is much elegant for the situation given in the question as given here
SqlConnection with using block (scroll down to see the using block)[^]

Checking SqlConnection.State before opening or closing

5 solutions

Solution 1

Solution 2

Solution 3

Solution 4

Solution 5

Add your solution here

Preview 0

Existing Members

...or Join us