一:使用sqlcommand.executenonquery()方法插入
 foreach (DataRow datarow in datatable.Rows)
 {
 string sql = "INSERT INTO [Table_1]
 ([CompanyName],[CompanyCode],[Address],[Owner],[Memo])" +
 "VALUES('" + datarow["CompanyName"].ToString() + "'" +
 ",'" + datarow["CompanyCode"].ToString() + "'" +
 ",'" + datarow["Address"].ToString() + "'" +
 ",'" + datarow["Owner"].ToString() + "'" +
 ",'" + datarow["Memo"].ToString() + "')";
 using (SqlConnection sqlconn = new SqlConnection(connectionString))
 {
 sqlconn.Open();
 SqlCommand sqlcommand = new SqlCommand(sql, sqlconn);
 sqlcommand.ExecuteNonQuery();
 sqlconn.Close();
 }
 }
二:使用sqldataadapter.update(dataset,tablename);
 SqlCommand insertcommand = new SqlCommand("INSERT INTO [Table_1]([CompanyName],[CompanyCode],[Address],[Owner],[Memo])" +
 "VALUES(@CompanyName, @CompanyCode,@Address,@Owner,@Memo)",new SqlConnection(connectionString));
 insertcommand.Parameters.Add("@CompanyName", SqlDbType.NChar, 50, "CompanyName");
 insertcommand.Parameters.Add("@CompanyCode", SqlDbType.NChar, 25, "CompanyCode");
 insertcommand.Parameters.Add("@Address", SqlDbType.NChar, 255, "Address");
 insertcommand.Parameters.Add("@Owner", SqlDbType.NChar, 25, "Owner");
 insertcommand.Parameters.Add("@Memo", SqlDbType.NChar, 255, "Memo");
 sqldataadapter.InsertCommand = insertcommand;
 sqldataadapter.Update(dataset, "Table_1"); 
 三:使用sqlbulkcopy.writetoserver(datatable)
 SqlBulkCopy sqlbulkcopy = new SqlBulkCopy(connectionString, SqlBulkCopyOptions.UseInternalTransaction);
 sqlbulkcopy.DestinationTableName = "Table_1";//数据库中的表名
 sqlbulkcopy.WriteToServer(dataset.Tables[0]);