insert与DataAdapter.update()哪个效率高?
最近在写一个数据导入的程序,从excel中读取数据,再插入到db中,如果采用insert语句或procedure逐行插入数据,每次都需要sqlconnection.open(),sqlconnection.close(),我想是不是会产生很大的开销。而DataSet自身带有update的方法,听说可以打批量的插入数据,而且性能很高。所以我写了个程序测试一下写入的速度(代码如下),但是另我惊讶的是测试结果如下:
生产数据条数:10000
insert插入10000条记录时间:00:00:04.8593750
dataset.update插入10000条记录时间:00:00:05.5781250
为什么会这样呢,不是说insert的系统开销大于dataset.update()的吗?请各位指点。
另外,还有什么更好,效率更高的数据批量插入DB的方法。谢谢。
private void testinputdate()
{
DateTime startdate = DateTime.Now;
SqlConnection sqlconnection = new SqlConnection(connectionString);
SqlDataAdapter sqldataadapter = new SqlDataAdapter("select * from Table_1 where 1=2", sqlconnection);
DataSet dataset = new DataSet();
sqldataadapter.Fill(dataset, "Table_1");
Console.WriteLine("执行查询时间:{0}",(DateTime.Now - startdate).ToString());
startdate=DateTime.Now;
DataTable datatable = dataset.Tables[0];
for (int i = 0; i < 100000; i++)
{
DataRow datarow = datatable.NewRow();
datarow["CompanyName"] = "companyname"+string.Format("{0:0000}",i);
datarow["CompanyCode"] = "companycode" + string.Format("{0:0000}", i);
datarow["Address"] = "address" + string.Format("{0:0000}", i);
datarow["Owner"] = "owner" + string.Format("{0:0000}", i);
datarow["Memo"] = "memo" + string.Format("{0:0000}", i);
datatable.Rows.Add(datarow);
}
Console.WriteLine("生成数据时间:{0}", (DateTime.Now - startdate).ToString());
Console.WriteLine("生产数据条数:{0}", datatable.Rows.Count);
//使用insert
startdate = DateTime.Now;
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();
}
}
Console.WriteLine("插入{0}条记录时间:{1}", datatable.Rows.Count, DateTime.Now - startdate);
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;
//使用dataadapter.update
startdate = DateTime.Now;
sqldataadapter.Update(dataset, "Table_1");
Console.WriteLine("插入{0}条记录时间:{1}", datatable.Rows.Count, DateTime.Now - startdate);
}