我以这种方式执行命令:
var Command = new SqlCommand(cmdText, Connection, tr);
Command.ExecuteNonQuery();
命令中有一个错误,但是.NET没有抛出任何错误消息。 我怎样才能知道命令没有正常执行,并且如何获取异常?
我以这种方式执行命令:
var Command = new SqlCommand(cmdText, Connection, tr);
Command.ExecuteNonQuery();
命令中有一个错误,但是.NET没有抛出任何错误消息。 我怎样才能知道命令没有正常执行,并且如何获取异常?
仅当错误的严重程度为16或更高时,您才会在C#中获得异常。如果您使用PRINT,您将不会在.NET中收到异常。
如果您可以编辑触发错误代码,则会在C#中引发SqlException:
RAISERROR('Some error message', 16, 1)
你可以通过访问 SqlException.Errors 集合来获取每个单独的错误。
顺便提一下 - 如果你在 RAISERROR
后没有直接使用 RETURN
,SQL Server 会继续运行命令。如果你不返回,可能会收到多个错误。
.NET确实会在严重性为16或以上时引发错误消息(因为它会抛出异常),此消息将包含在.Message
中。如果您使用较低严重性的RAISERROR
(或使用PRINT
),则需要订阅连接上的InfoMessage
事件。
ExecuteNonQuery()
消耗TDS(因此看到错误),但是ExecuteScalar()
不会消耗它?我本来希望ExecuteNonQuery()
根本不会消耗任何东西,尽管我实际上更喜欢它这样做。 - Nelson RothermelExecuteReader
存在问题。然而,我的研究(https://dev59.com/z0jSa4cB1Zd3GeqPCA3t,https://dev59.com/G3E95IYBdhLWcg3wPbZ7#2400019,http://www.sqlservercentral.com/Forums/Topic1070081-392-1.aspx#bm1070131)表明,如果错误在第一个结果集之后,`ExecuteScalar`也不会捕获错误。我想确定最好的方法是尝试一下。 - Nelson Rothermelselect ...; raiserror(...)
需要你执行 DataReader.NextResult()
才能捕获到错误。 - Nelson Rothermel受M Hassan、Stefan Steiger和Mark Gravell在该线程中工作的启发,这里是一个最小的概念验证示例,说明了这里正在发生什么:
private static void DoSql()
{
// Errors of severity level of 10 or less
// will NOT bubble up to .Net as an Exception to be caught in the usual way
const string sql = @"RAISERROR('A test error message of low severity', 10, 1)";
using (SqlConnection conn = new SqlConnection(myConnString))
{
conn.Open();
// Hook up my listener to the connection message generator
conn.InfoMessage += new SqlInfoMessageEventHandler(MySqlMessageHandler);
using (SqlCommand cmd = new SqlCommand(sql, conn))
{
cmd.ExecuteNonQuery();
// code happily carries on to this point
// despite the sql Level 10 error that happened above
}
}
}
private static void MySqlMessageHandler(object sender, SqlInfoMessageEventArgs e)
{
// This gets all the messages generated during the execution of the SQL,
// including low-severity error messages.
foreach (SqlError err in e.Errors)
{
// TODO: Something smarter than this for handling the messages
MessageBox.Show(err.Message);
}
}
只有高严重性错误才会在ExecuteNonQuery中抛出。我观察到OdbcCommand.ExecuteNonQuery()方法还有另一种情况。SqlCommand.ExecuteNonQuery()也可能是如此。如果CommandText属性中包含的SQL语句是单个语句(例如:INSERT INTO table (col1,col2) VALUES (2,'ABC');),并且以上语句中存在外键或主键违规,ExecuteNonQuery将抛出异常。然而,如果您的CommandText是一个批处理,其中有多个由分号分隔的SQL语句(例如:多个INSERTS或UPDATES),如果其中一个失败,ExecuteNonQuery不会抛出异常。您需要显式检查方法返回的受影响记录数。仅在try{}Catch{}中放置代码是没有帮助的。
在使用Oracle ODP.Net的WCF服务中,我发现这对我很有效 -
try
{
cmd.Connection = conn;
conn.Open();
cmd.ExecuteNonQuery();
}
catch (OracleException oex)
{
string errmsg = oex.Message;
Logger.Instance.WriteLog(@"Some error --> " + errmsg);
throw new Exception(errmsg);
}
catch (Exception ex)
{
throw ex;
}
finally
{
cleanup...
}
当命令完成时,使用try catch结合这段代码,返回错误:
SqlCommand.EndExecuteNonQuery(result)
这是我的完整课程代码:
Imports System.Data.SqlClient
Imports System.DirectoryServices.ActiveDirectory
Class clsExecuteAsync
Public Event EnProceso(Identificador As Integer, Mensaje As String)
Public Event Finalizado(IDentificador As Integer, Mensaje As String)
Public Event CancelarProcesoEnEjecucion(Identificador As Integer, ByRef Cancel As Boolean)
Dim Cancelar As Boolean
Sub CancelarProceso()
Cancelar = True
End Sub
Function test() As Boolean
' This is a simple example that demonstrates the usage of the
' BeginExecuteNonQuery functionality.
' The WAITFOR statement simply adds enough time to prove the
' asynchronous nature of the command.
Dim commandText As String = "UPDATE Production.Product SET ReorderPoint = ReorderPoint + 1 " & "WHERE ReorderPoint Is Not Null;" & "WAITFOR DELAY '0:0:3';" & "UPDATE Production.Product SET ReorderPoint = ReorderPoint - 1 " & "WHERE ReorderPoint Is Not Null"
Return (RunCommandAsynchronously(0, commandText, GetConnectionString()))
Console.WriteLine("Press ENTER to continue.")
Console.ReadLine()
End Function
Function ExecuteAsync(Identificador As Integer, Sql As String, Optional CadenaConexion As String = "") As String
If CadenaConexion = "" Then
CadenaConexion = clsIni.LeeIni("Provider")
End If
Return RunCommandAsynchronously(Identificador, Sql, CadenaConexion)
End Function
Function RunCommandAsynchronously(Identificador As Integer, commandText As String, connectionString As String) As String
' Given command text and connection string, asynchronously execute
' the specified command against the connection. For this example,
' the code displays an indicator as it is working, verifying the
' asynchronous behavior.
Dim Resultado As String = ""
Try
Dim connection As SqlConnection
Dim SqlCommand As SqlCommand
connection = New SqlConnection(connectionString)
Dim count As Integer = 0
'testint to catch the error, but not run for me
AddHandler connection.InfoMessage, AddressOf ErrorEnConexion
SqlCommand = New SqlCommand(commandText, connection)
connection.Open()
Dim result As IAsyncResult = SqlCommand.BeginExecuteNonQuery()
While Not result.IsCompleted
Console.WriteLine("Waiting ({0})", count = count + 1)
' Wait for 1/10 second, so the counter
' does not consume all available resources
' on the main thread.
System.Threading.Thread.Sleep(100)
RaiseEvent EnProceso(Identificador, commandText)
Application.DoEvents()
If Cancelar Then
Cancelar = False
'cancelar
Dim Cancel As Boolean = False
RaiseEvent CancelarProcesoEnEjecucion(Identificador, Cancel)
If Cancel = False Then
Resultado = "Cancelado"
GoTo SALIR
End If
End If
End While
'Console.WriteLine("Command complete. Affected {0} rows.", Command.EndExecuteNonQuery(Result))
' MsgBox("El comando se ejecutó. " & SqlCommand.EndExecuteNonQuery(result), MsgBoxStyle.Information)
'detect error: this code lunch and error: Cath with try cacth code
SqlCommand.EndExecuteNonQuery(result)
RaiseEvent Finalizado(Identificador, SqlCommand.EndExecuteNonQuery(result))
Resultado = "OK"
Catch ex As SqlException
Console.WriteLine("Error ({0}): {1}", ex.Number, ex.Message)
Resultado = ex.Message
Catch ex As InvalidOperationException
Console.WriteLine("Error: {0}", ex.Message)
Resultado = ex.Message
Catch ex As Exception
' You might want to pass these errors
' back out to the caller.
Console.WriteLine("Error: {0}", ex.Message)
Resultado = ex.Message
End Try
SALIR:
Return Resultado
End Function
Private Sub ErrorEnConexion(sender As Object, e As SqlInfoMessageEventArgs)
MsgBox(e.Message)
End Sub
Private Function GetConnectionString() As String
' To avoid storing the connection string in your code,
' you can retrieve it from a configuration file.
' If you have not included "Asynchronous Processing=true" in the
' connection string, the command is not able
' to execute asynchronously.
Return "Data Source=(local);Integrated Security=SSPI;" & "Initial Catalog=AdventureWorks; Asynchronous Processing=true"
End Function
End Class
请尝试以下方法。
附注:仅仅因为您使用了事务,并不意味着您可以忽略异常处理和回滚。
public static void MessageEventHandler( object sender, SqlInfoMessageEventArgs e ) {
foreach( SqlError error in e.Errors ) {
Console.WriteLine("problem with sql: "+error);
throw new Exception("problem with sql: "+error);
}
}
public static int executeSQLUpdate(string database, string command) {
SqlConnection connection = null;
SqlCommand sqlcommand = null;
int rows = -1;
try {
connection = getConnection(database);
connection.InfoMessage += new SqlInfoMessageEventHandler( MessageEventHandler );
sqlcommand = connection.CreateCommand();
sqlcommand.CommandText = command;
connection.Open();
rows = sqlcommand.ExecuteNonQuery();
} catch(Exception e) {
Console.Write("executeSQLUpdate: problem with command:"+command+"e="+e);
Console.Out.Flush();
throw new Exception("executeSQLUpdate: problem with command:"+command,e);
} finally {
if(connection != null) { connection.Close(); }
}
return rows;
}
这是正确的事务处理方式:
//public static void ExecuteInTransaction(Subtext.Scripting.SqlScriptRunner srScriptRunner)
public override void ExecuteInTransaction(string strSQL)
{
System.Data.Odbc.OdbcTransaction trnTransaction = null;
try
{
System.Threading.Monitor.Enter(m_SqlConnection);
if (isDataBaseConnectionOpen() == false)
OpenSQLConnection();
trnTransaction = m_SqlConnection.BeginTransaction();
try
{
/*
foreach (Subtext.Scripting.Script scThisScript in srScriptRunner.ScriptCollection)
{
System.Data.Odbc.OdbcCommand cmd = new System.Data.Odbc.OdbcCommand(scThisScript.ScriptText, m_sqlConnection, trnTransaction);
cmd.ExecuteNonQuery();
}
*/
// pfff, mono C# compiler problem...
// System.Data.Odbc.OdbcCommand cmd = new System.Data.Odbc.OdbcCommand(strSQL, m_SqlConnection, trnTransaction);
System.Data.Odbc.OdbcCommand cmd = this.m_SqlConnection.CreateCommand();
cmd.CommandText = strSQL;
cmd.ExecuteNonQuery();
trnTransaction.Commit();
} // End Try
catch (System.Data.Odbc.OdbcException exSQLerror)
{
Log(strSQL);
Log(exSQLerror.Message);
Log(exSQLerror.StackTrace);
trnTransaction.Rollback();
} // End Catch
} // End Try
catch (Exception ex)
{
Log(strSQL);
Log(ex.Message);
Log(ex.StackTrace);
} // End Catch
finally
{
strSQL = null;
if(m_SqlConnection.State != System.Data.ConnectionState.Closed)
m_SqlConnection.Close();
System.Threading.Monitor.Exit(m_SqlConnection);
} // End Finally
} // End Sub ExecuteInTransaction
using
和lock
会更加合适;此外,你没有重新抛出异常,而且在每个级别记录日志是过度的(这就是.StackTrace
的作用)。这样做会导致静默失败,我认为这非常糟糕。还有,为什么要锁定连接?如果两个线程甚至可以看到相同的连接,那么你的做法是错误的,我认为。如果有什么问题,那对我来说看起来像是如何不处理错误的完美示例。 - Marc GravellEnter()
的调用可能失败 - 这意味着您没有获取锁 - 然后尝试Exit()
(即使您没有获取锁)。但更重要的是,为什么要写额外的代码呢? - Marc Gravellconn.Open();
就在那里了。实际上,我们使用一个 EnsureOpen()
扩展方法来内部处理,它使用 IDisposable
并在 dispose 时打开(如果没有打开)并关闭它(如果它打开了)。这是一个很方便的包装实用程序方法。虽然我们重复使用连接的程度与我试图说明的主要观点无关,但我并没有专注于这一点。 - Marc Gravell你可以使用 try/catch 捕获 SqlException 异常
try
{
//.......
Command.ExecuteNonQuery();
}
catch (SqlException ex)
{
log (SqlExceptionMessage(ex).ToString());
}
以下方法可以捕获SqlException的详细信息,这些信息可以记录或显示给用户
public StringBuilder SqlExceptionMessage(SqlException ex)
{
StringBuilder sqlErrorMessages = new StringBuilder("Sql Exception:\n");
foreach (SqlError error in ex.Errors)
{
sqlErrorMessages.AppendFormat("Mesage: {0}\n", error.Message)
.AppendFormat("Severity level: {0}\n", error.Class)
.AppendFormat("State: {0}\n", error.State)
.AppendFormat("Number: {0}\n", error.Number)
.AppendFormat("Procedure: {0}\n", error.Procedure)
.AppendFormat("Source: {0}\n", error.Source)
.AppendFormat("LineNumber: {0}\n", error.LineNumber)
.AppendFormat("Server: {0}\n", error.Server)
.AppendLine(new string('-',error.Message.Length+7));
}
return sqlErrorMessages;
}
Sql Exception:
Mesage: Error converting data type nvarchar to datetime.
Severity level: 16
State: 5
Number: 8114
Procedure: Sales by Year
Source: .Net SqlClient Data Provider
LineNumber: 0
Server: myserver
-------------------------------------------------------
NonQuery
方法 - 如果您使用实际名称,它会更清晰...编辑... - Marc Gravell