我有以下代码:

Using cmd As SqlCommand = Connection.CreateCommand
    cmd.CommandText = "UPDATE someTable SET Value = @Value"
    cmd.CommandText &= " WHERE Id = @Id"
    cmd.Parameters.AddWithValue("@Id", 1234)
    cmd.Parameters.AddWithValue("@Value", "myValue")
    cmd.ExecuteNonQuery
End Using

我想知道是否有任何方法来获得最终的SQL语句作为字符串,它应该看起来像这样:

UPDATE someTable SET Value = "myValue" WHERE Id = 1234

如果有人想知道我为什么要这么做

用于记录(失败的)语句 可以将其复制粘贴到企业管理器中进行测试


当前回答

这个方法现在对我很有效。也许它对某人有用。请原谅所有的冗余。

    Public Shared Function SqlString(ByVal cmd As SqlCommand) As String
    Dim sbRetVal As New System.Text.StringBuilder()
    For Each item As SqlParameter In cmd.Parameters
        Select Case item.DbType
            Case DbType.String
                sbRetVal.AppendFormat("DECLARE {0} AS VARCHAR(255)", item.ParameterName)
                sbRetVal.AppendLine()
                sbRetVal.AppendFormat("SET {0} = '{1}'", item.ParameterName, item.Value)
                sbRetVal.AppendLine()

            Case DbType.DateTime
                sbRetVal.AppendFormat("DECLARE {0} AS DATETIME", item.ParameterName)
                sbRetVal.AppendLine()
                sbRetVal.AppendFormat("SET {0} = '{1}'", item.ParameterName, item.Value)
                sbRetVal.AppendLine()

            Case DbType.Guid
                sbRetVal.AppendFormat("DECLARE {0} AS UNIQUEIDENTIFIER", item.ParameterName)
                sbRetVal.AppendLine()
                sbRetVal.AppendFormat("SET {0} = '{1}'", item.ParameterName, item.Value)
                sbRetVal.AppendLine()

            Case DbType.Int32
                sbRetVal.AppendFormat("DECLARE {0} AS int", item.ParameterName)
                sbRetVal.AppendLine()
                sbRetVal.AppendFormat("SET {0} = {1}", item.ParameterName, item.Value)
                sbRetVal.AppendLine()

            Case Else
                Stop

        End Select
    Next

    sbRetVal.AppendLine("")
    sbRetVal.AppendLine(cmd.CommandText)

    Return sbRetVal.ToString()
End Function

其他回答

晚回答,我知道,但我也想这样做,所以我可以记录SQL。以下内容很简短,可以满足我的需要。

下面生成的SQL可以在SSMS中复制/粘贴(它正确地将参数替换为值)。您可以添加更多类型,但这满足我在这种情况下使用的所有类型。

    private static void LogSQL(SqlCommand cmd)
        {
            string query = cmd.CommandText;

            foreach (SqlParameter prm in cmd.Parameters)
            {
                switch (prm.SqlDbType)
                {
                    case SqlDbType.Bit:
                        int boolToInt = (bool)prm.Value ? 1 : 0;
                        query = query.Replace(prm.ParameterName, string.Format("{0}", (bool)prm.Value ? 1 : 0));
                        break;
                    case SqlDbType.Int:
                        query = query.Replace(prm.ParameterName, string.Format("{0}", prm.Value));
                        break;
                    case SqlDbType.VarChar:
                        query = query.Replace(prm.ParameterName, string.Format("'{0}'", prm.Value));
                        break;
                    default:
                        query = query.Replace(prm.ParameterName, string.Format("'{0}'", prm.Value));
                        break;
                }
            }

            // the following is my how I write to my log - your use will vary
            logger.Debug("{0}", query);

            return;
        }

现在我可以在执行之前记录SQL:

LogSQL(queryCmd)
queryCmd.ExecuteNonQuery()

如果你正在使用SQL Server,你可以使用SQL Server Profiler(如果你有的话)来查看实际执行的命令字符串。这对于复制/粘贴测试很有用,但对于日志记录恐怕就没用了。

不能,因为它不会生成任何SQL。

参数化的查询(CommandText中的那个)作为准备好的语句被发送到SQL Server。执行命令时,参数和查询文本是分开处理的。在任何时间点都不会生成完整的SQL字符串。

您可以使用SQL Profiler来查看幕后操作。

正如@pkExec和@Alok提到的,使用Replace在100%的情况下都不能工作。 这是我在我们的DAL中使用的解决方案,它使用RegExp只“匹配整个单词”并正确格式化数据类型。因此,生成的SQL可以直接在MySQL Workbench(或SQLSMS等…)中测试:)

(根据使用的DBMS替换MySQLHelper.EscapeString()函数)

Dim query As String = cmd.CommandText
query = query.Replace("SET", "SET" & vbNewLine)
query = query.Replace("WHERE", vbNewLine & "WHERE")
query = query.Replace("GROUP BY", vbNewLine & "GROUP BY")
query = query.Replace("ORDER BY", vbNewLine & "ORDER BY")
query = query.Replace("INNER JOIN", vbNewLine & "INNER JOIN")
query = query.Replace("LEFT JOIN", vbNewLine & "LEFT JOIN")
query = query.Replace("RIGHT JOIN", vbNewLine & "RIGHT JOIN")
If query.Contains("UNION ALL") Then
    query = query.Replace("UNION ALL", vbNewLine & "UNION ALL" & vbNewLine)
ElseIf query.Contains("UNION DISTINCT") Then
    query = query.Replace("UNION DISTINCT", vbNewLine & "UNION DISTINCT" & vbNewLine)
Else
    query = query.Replace("UNION", vbNewLine & "UNION" & vbNewLine)
End If

For Each par In cmd.Parameters
    If par.Value Is Nothing OrElse IsDBNull(par.Value) Then
        query = RegularExpressions.Regex.Replace(query, par.ParameterName & "\b", "NULL")
    ElseIf TypeOf par.Value Is Date Then
        query = RegularExpressions.Regex.Replace(query, par.ParameterName & "\b", "'" & Format(par.Value, "yyyy-MM-dd HH:mm:ss") & "'")
    ElseIf TypeOf par.Value Is TimeSpan Then
        query = RegularExpressions.Regex.Replace(query, par.ParameterName & "\b", "'" & par.Value.ToString & "'")
    ElseIf TypeOf par.Value Is Double Or TypeOf par.Value Is Decimal Or TypeOf par.Value Is Single Then
        query = RegularExpressions.Regex.Replace(query, par.ParameterName & "\b", Replace(par.Value.ToString, ",", "."))
    ElseIf TypeOf par.Value Is Integer Or TypeOf par.Value Is UInteger Or TypeOf par.Value Is Long Or TypeOf par.Value Is ULong Then
        query = RegularExpressions.Regex.Replace(query, par.ParameterName & "\b", par.Value.ToString)
    Else
        query = RegularExpressions.Regex.Replace(query, par.ParameterName & "\b", "'" & MySqlHelper.EscapeString(CStr(par.Value)) & "'")
    End If
Next

例子:

SELECT * FROM order WHERE order_status = @order_status AND order_date = @order_date

将生成:

SELECT * FROM order WHERE order_status = 'C' AND order_date = '2015-01-01 00:00:00'

这是我用来将存储过程的参数列表输出到调试控制台的:

string query = (from SqlParameter p in sqlCmd.Parameters where p != null where p.Value != null select string.Format("Param: {0} = {1},  ", p.ParameterName, p.Value.ToString())).Aggregate(sqlCmd.CommandText, (current, parameter) => current + parameter);
Debug.WriteLine(query);

这将生成一个类似于下面的控制台输出:

Customer.prGetCustomerDetails: @Offset = 1,  Param: @Fetch = 10,  Param: @CategoryLevel1ID = 3,  Param: @VehicleLineID = 9,  Param: @SalesCode1 = bce,  

我把这段代码直接放在我希望调试的任何过程的下面,它类似于sql分析器会话,但使用c#。