SQL 연결이 열려 있는지 또는 닫혀 있는지 확인

SQL 연결이 열려 있는지 또는 닫혀 있는지 확인

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내가 사용하고 있던 열려 있는지 닫혀 있는지 어떻게 확인합니까?

 if (SQLOperator.SQLCONNECTION.State.Equals("Open"))

그러나 State가 'Open'인 경우에도이 검사에서 실패합니다.

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SqlConnection.State를 사용해야합니다.

예 :

using System.Data;

if (myConnection != null && myConnection.State == ConnectionState.Closed)
{
   // do something
   // ...
}

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내가 사용하는 것은 다음과 같습니다.

if (mySQLConnection.State != ConnectionState.Open)
{
    mySQLConnection.Close();
    mySQLConnection.Open();
}

내가 단순히 사용하지 않는 이유 :

if (mySQLConnection.State == ConnectionState.Closed)
{
    mySQLConnection.Open();
}

ConnectionState도 다음과 같을 수 있기 때문입니다.

Broken, Connnecting, Executing, Fetching

이외에

Open, Closed

또한 Microsoft는 연결을 닫았다가 다시 열면 "상태 값이 새로 고쳐집니다"라고 말합니다. 여기를 참조하십시오 http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection.state(v=vs.110).aspx

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.NET 문서에 따르면 상태 속성 : ConnectionState 값의 비트 조합

그래서 확인해야 할 것 같아요

!myConnection.State.HasFlag(ConnectionState.Open)

대신에

myConnection.State != ConnectionState.Open

State는 여러 플래그를 가질 수 있기 때문입니다.

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MySQL 연결이 열려 있는지 확인

ConnectionState state = connection.State;
if (state == ConnectionState.Open)
{
    return true;
}
else
{
    connection.Open();
    return true;
}

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당신은 또한 이것을 사용할 수 있습니다

if (SQLCON.State == ConnectionState.Closed)
{
     SQLCON.Open();
}

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This code is a little more defensive, before opening a connection, check state. If connection state is Broken then we should try to close it. Broken means that the connection was previously opened and not functioning correctly. The second condition determines that connection state must be closed before attempting to open it again so the code can be called repeatedly.

// Defensive database opening logic.

if (_databaseConnection.State == ConnectionState.Broken) {
    _databaseConnection.Close();
}

if (_databaseConnection.State == ConnectionState.Closed) {
    _databaseConnection.Open();
}

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To check the database connection state you can just simple do the following

if(con.State == ConnectionState.Open){}

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To check OleDbConnection State use this:

if (oconn.State == ConnectionState.Open)
{
    oconn.Close();
}

State return the ConnectionState

public override ConnectionState State { get; }

Here are the other ConnectionState enum

public enum ConnectionState
    {
        //
        // Summary:
        //     The connection is closed.
        Closed = 0,
        //
        // Summary:
        //     The connection is open.
        Open = 1,
        //
        // Summary:
        //     The connection object is connecting to the data source. (This value is reserved
        //     for future versions of the product.)
        Connecting = 2,
        //
        // Summary:
        //     The connection object is executing a command. (This value is reserved for future
        //     versions of the product.)
        Executing = 4,
        //
        // Summary:
        //     The connection object is retrieving data. (This value is reserved for future
        //     versions of the product.)
        Fetching = 8,
        //
        // Summary:
        //     The connection to the data source is broken. This can occur only after the connection
        //     has been opened. A connection in this state may be closed and then re-opened.
        //     (This value is reserved for future versions of the product.)
        Broken = 16
    }

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I use the following manner sqlconnection.state

if(conexion.state != connectionState.open())
   conexion.open();

참고URL : https://stackoverflow.com/questions/6943933/check-if-sql-connection-is-open-or-closed