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

为我的解决方案使用了Flapper的部分代码,它返回整个SQL字符串,包括在MS SQL SMS中运行的参数值。

public string ParameterValueForSQL(SqlParameter sp)
    {
        string retval = "";

        switch (sp.SqlDbType)
        {
            case SqlDbType.Char:
            case SqlDbType.NChar:
            case SqlDbType.NText:
            case SqlDbType.NVarChar:
            case SqlDbType.Text:
            case SqlDbType.Time:
            case SqlDbType.VarChar:
            case SqlDbType.Xml:
            case SqlDbType.Date:
            case SqlDbType.DateTime:
            case SqlDbType.DateTime2:
            case SqlDbType.DateTimeOffset:
                if (sp.Value == DBNull.Value)
                {
                    retval = "NULL";
                }
                else
                {
                    retval = "'" + sp.Value.ToString().Replace("'", "''") + "'";
                }
                break;

            case SqlDbType.Bit:
                if (sp.Value == DBNull.Value)
                {
                    retval = "NULL";
                }
                else
                {
                    retval = ((bool)sp.Value == false) ? "0" : "1";
                }
                break;

            default:
                if (sp.Value == DBNull.Value)
                {
                    retval = "NULL";
                }
                else
                {
                    retval = sp.Value.ToString().Replace("'", "''");
                }
                break;
        }

        return retval;
    }


    public string CommandAsSql(SqlCommand sc)
    {
        string sql = sc.CommandText;

        sql = sql.Replace("\r\n", "").Replace("\r", "").Replace("\n", "");
        sql = System.Text.RegularExpressions.Regex.Replace(sql, @"\s+", " ");

        foreach (SqlParameter sp in sc.Parameters)
        {
            string spName = sp.ParameterName;
            string spValue = ParameterValueForSQL(sp);
            sql = sql.Replace(spName, spValue);
        }

        sql = sql.Replace("= NULL", "IS NULL");
        sql = sql.Replace("!= NULL", "IS NOT NULL");
        return sql;
    }

其他回答

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
//For Oracle db in the sql text the parameters could be like :ID,:NAME etc.
//This is same as above Seyed Hossein Mirheydari, but slightly improved, 
//this works with parameter names well.
//Further is straight simple one, you need to format for datatypes 
//after query is generated.
    private string GetFullOraQuery(OracleCommand cmd)
    {
        string query = cmd.CommandText;
        foreach (OracleParameter p in cmd.Parameters)
        {
            query = query.Replace(":" + p.ParameterName, ((p.Value == null) ? "" : p.Value.ToString()));
        }
        return query;
    }

虽然不完美,这里有一些我为TSQL做的东西-可以很容易地调整为其他口味…如果没有其他的话,它将为你自己的改进提供一个起点:)

这在数据类型和输出参数等方面做得很好,类似于在SSMS中使用“执行存储过程”。我们主要使用sp,所以“text”命令不考虑参数等

    public static String ParameterValueForSQL(this SqlParameter sp)
    {
        String retval = "";

        switch (sp.SqlDbType)
        {
            case SqlDbType.Char:
            case SqlDbType.NChar:
            case SqlDbType.NText:
            case SqlDbType.NVarChar:
            case SqlDbType.Text:
            case SqlDbType.Time:
            case SqlDbType.VarChar:
            case SqlDbType.Xml:
            case SqlDbType.Date:
            case SqlDbType.DateTime:
            case SqlDbType.DateTime2:
            case SqlDbType.DateTimeOffset:
                retval = "'" + sp.Value.ToString().Replace("'", "''") + "'";
                break;

            case SqlDbType.Bit:
                retval = (sp.Value.ToBooleanOrDefault(false)) ? "1" : "0";
                break;

            default:
                retval = sp.Value.ToString().Replace("'", "''");
                break;
        }

        return retval;
    }

    public static String CommandAsSql(this SqlCommand sc)
    {
        StringBuilder sql = new StringBuilder();
        Boolean FirstParam = true;

        sql.AppendLine("use " + sc.Connection.Database + ";");
        switch (sc.CommandType)
        {
            case CommandType.StoredProcedure:
                sql.AppendLine("declare @return_value int;");

                foreach (SqlParameter sp in sc.Parameters)
                {
                    if ((sp.Direction == ParameterDirection.InputOutput) || (sp.Direction == ParameterDirection.Output))
                    {
                        sql.Append("declare " + sp.ParameterName + "\t" + sp.SqlDbType.ToString() + "\t= ");

                        sql.AppendLine(((sp.Direction == ParameterDirection.Output) ? "null" : sp.ParameterValueForSQL()) + ";");

                    }
                }

                sql.AppendLine("exec [" + sc.CommandText + "]");

                foreach (SqlParameter sp in sc.Parameters)
                {
                    if (sp.Direction != ParameterDirection.ReturnValue)
                    {
                        sql.Append((FirstParam) ? "\t" : "\t, ");

                        if (FirstParam) FirstParam = false;

                        if (sp.Direction == ParameterDirection.Input)
                            sql.AppendLine(sp.ParameterName + " = " + sp.ParameterValueForSQL());
                        else

                            sql.AppendLine(sp.ParameterName + " = " + sp.ParameterName + " output");
                    }
                }
                sql.AppendLine(";");

                sql.AppendLine("select 'Return Value' = convert(varchar, @return_value);");

                foreach (SqlParameter sp in sc.Parameters)
                {
                    if ((sp.Direction == ParameterDirection.InputOutput) || (sp.Direction == ParameterDirection.Output))
                    {
                        sql.AppendLine("select '" + sp.ParameterName + "' = convert(varchar, " + sp.ParameterName + ");");
                    }
                }
                break;
            case CommandType.Text:
                sql.AppendLine(sc.CommandText);
                break;
        }

        return sql.ToString();
    }

这将产生沿着这些线的输出…

use dbMyDatabase;
declare @return_value int;
declare @OutTotalRows   BigInt  = null;
exec [spMyStoredProc]
    @InEmployeeID = 1000686
    , @InPageSize = 20
    , @InPage = 1
    , @OutTotalRows = @OutTotalRows output
;
select 'Return Value' = convert(varchar, @return_value);
select '@OutTotalRows' = convert(varchar, @OutTotalRows);

一个衬套:

string.Join(",", from SqlParameter p in cmd.Parameters select p.ToString()) 

sql命令查询将通过exec sp_executesql执行,所以这里有另一种方法来获取语句作为字符串(SqlCommand扩展方法):

public static string ToSqlStatement(this SqlCommand cmd)
{
    return $@"EXECUTE sp_executesql N'{cmd.CommandText.Replace("'", "''")}'{cmd.Parameters.ToSqlParameters()}";
}

private static string ToSqlParameters(this SqlParameterCollection col)
{
    if (col.Count == 0)
        return string.Empty;
    var parameters = new List<string>();
    var parameterValues = new List<string>();
    foreach (SqlParameter param in col)
    {
        parameters.Add($"{param.ParameterName}{param.ToSqlParameterType()}");
        parameterValues.Add($"{param.ParameterName} = {param.ToSqlParameterValue()}");
    }
    return $",N\'{string.Join(",", parameters)}\',{string.Join(",", parameterValues)}";
}

private static object ToSqlParameterType(this SqlParameter param)
{
    var paramDbType = param.SqlDbType.ToString().ToLower();
    if (param.Precision != 0 && param.Scale != 0)
        return $"{paramDbType}({param.Precision},{param.Scale})";
    if (param.Precision != 0)
        return $"{paramDbType}({param.Precision})";
    switch (param.SqlDbType)
    {
        case SqlDbType.VarChar:
        case SqlDbType.NVarChar:
            string s = param.SqlValue?.ToString() ?? string.Empty;
            return paramDbType + (s.Length > 0 ? $"({s.Length})" : string.Empty);
        default:
            return paramDbType;
    }
}

private static string ToSqlParameterValue(this SqlParameter param)
{
    switch (param.SqlDbType)
    {
        case SqlDbType.Char:
        case SqlDbType.Date:
        case SqlDbType.DateTime:
        case SqlDbType.DateTime2:
        case SqlDbType.DateTimeOffset:
        case SqlDbType.NChar:
        case SqlDbType.NText:
        case SqlDbType.NVarChar:
        case SqlDbType.Text:
        case SqlDbType.Time:
        case SqlDbType.VarChar:
        case SqlDbType.Xml:
            return $"\'{param.SqlValue.ToString().Replace("'", "''")}\'";
        case SqlDbType.Bit:
            return param.SqlValue.ToBooleanOrDefault() ? "1" : "0";
        default:
            return param.SqlValue.ToString().Replace("'", "''");
    }
}

public static bool ToBooleanOrDefault(this object o, bool defaultValue = false)
{
    if (o == null)
        return defaultValue;
    string value = o.ToString().ToLower();
    switch (value)
    {
        case "yes":
        case "true":
        case "ok":
        case "y":
            return true;
        case "no":
        case "false":
        case "n":
            return false;
        default:
            bool b;
            if (bool.TryParse(o.ToString(), out b))
                return b;
            break;
    }
    return defaultValue;
}