Question

与this question相关：我正在尝试编写一个“INSERT”循环：我有以下查询：

CommandText = "INSERT into sample2Prot(timestp,idq,idz,prot,Lhowmany,Rhowmany) VALUES(@timestp,@idq,@idz,@prot,@Lhowmany,@Rhowmany)";

当我执行我的代码（可以在下面找到）时，我收到以下错误：

'@ timestp'无法由SqlParameterCollection处理。（“timestp”= tableNames [0]，字符串类型）

for (int j = 0; j < tableNames.Count; j++)

// tableNames contains the name of the columns, tableTypes the types of the columns
// tableTypes contains
{
     if (tableTypes[j] == "INTEGER")
     {
           myCommand3.Parameters.Add("@" + tableNames[j], System.Data.SqlDbType.Int);
           Console.WriteLine("@" + tableNames[j]);
     }
     else
     {
           myCommand3.Parameters.Add("@" + tableNames[j], System.Data.SqlDbType.VarChar);
           Console.WriteLine("@" + tableNames[j]);
     }

}

Console.WriteLine(myCommand3.CommandText);
for (int f = 0; f < total.Count(); f++)
{
     for (int k = 0; k < tableNames.Count; k++)
     {
           myCommand3.Parameters.Clear();
           myCommand3.Parameters["@" + tableNames[k]].Value = total[f][k];
     }

     myCommand3.ExecuteNonQuery();
}

有人有想法吗？不要在于要求更高的精确度。

Answer 1

for (int f = 0; f < total.Count(); f++)
{
     for (int k = 0; k < tableNames.Count; k++)
     {
           myCommand3.Parameters.Clear(); // < ==== PROBLEM is here!
           // After clearing the Parameters, there is no Parameter "["@" + tableNames[k]]"
           // hence "SqlParameter mit ParameterName '@timestp' ist nicht in SqlParameterCollection enthalten."
           // (eng: SqlParameterCollection does not contain SqlParameter with name '@timestp' )
           myCommand3.Parameters["@" + tableNames[k]].Value = total[f][k];
     }

     myCommand3.ExecuteNonQuery();
}

在上面的代码中，移动Clear()语句，如下所示：

for (int f = 0; f < total.Count(); f++)
{
     for (int k = 0; k < tableNames.Count; k++)
     {
           myCommand3.Parameters["@" + tableNames[k]].Value = total[f][k];
     }
     myCommand3.ExecuteNonQuery();
}
myCommand3.Parameters.Clear();

数据插入循环不起作用

1 个答案: