错误“已经有与此命令相关联的打开的DataReader，必须先关闭” [英] error 'there is already an open datareader associated with this command which must be closed first'

问题描述

运行时错误已经有与此命令必须先关闭相关联的打开的DataReader

runtime error 'there is already an open datareader associated with this command which must be closed first'

objCommand = new SqlCommand("SELECT field1, field2 FROM sourcetable", objConn);

objDataReader = objCommand.ExecuteReader();

while (objDataReader.Read())
{
objInsertCommand = new SqlCommand("INSERT INTO tablename (field1, field2) VALUES (3, '" + objDataReader[0] + "')", objConn);
objInsertCommand.ExecuteNonQuery();//Here is the error
}
objDataReader.Close();

我不能在这里定义的任何存储过程。 任何帮助将我们的AP preciated。

I cannot define any stored procedure here. Any help would we appreciated.

推荐答案

如何把数据变成通过填充DataSet，然后通过迭代通过NonQuery来执行插入？

How about pulling the data into a DataSet via Fill and then iterate through that to perform your insert via NonQuery?

IDbDataAdapter da;
IDbCommand selectCommand = connection.CreateCommand();
selectCommand.CommandType = CommandType.Text;
selectCommand.CommandText = "SELECT field1, field2 FROM sourcetable";
connection.Open();
DataSet selectResults= new DataSet();
da.Fill(selectResults); // get dataset
selectCommand.Dispose();
IDbCommand insertCommand;

foreach(DataRow row in selectResults.Tables[0].Rows)
{
    insertCommand = connection.CreateCommand();
    insertCommand.CommandType = CommandType.Text;
    insertCommand.CommandText = "INSERT INTO tablename (field1, field2) VALUES (3, '" + row["columnName"].ToString() + "'";   
}
insertCommand.Dispose();
connection.Close();

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