//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;
    }

从参数命令到非参数命令，可以修改

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

To

Private sub Update( byval myID as Int32, byval myVal as String)
    Using cmd As SqlCommand = Connection.CreateCommand
        cmd.CommandText = "UPDATE someTable SET Value = '" & myVaL & "'" & _
                          " WHERE Id = " & myID  
        cmd.ExecuteNonQuery
    End Using
End sub

为了记录日志，恐怕没有更好的方法了，只能自己构造字符串:

string query = cmd.CommandText;

foreach (SqlParameter p in cmd.Parameters)
{
    query = query.Replace(p.ParameterName, p.Value.ToString());
}

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。

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;
}

如果你的数据库是Oracle, sql文本包含动态变量，如:1，:2，…然后你可以使用:

string query = cmd.CommandText;
int i = 1;
foreach (OracleParameter p in cmd.Parameters)
  {
    query = query.Replace(":"+i.ToString(),((p.Value==null)?"":p.Value.ToString()));
    i++;
  }