我有SQL Server CE 3.5数据库.我运行以下代码:
private void Load(string sql)
{
if (connection.State != ConnectionState.Open)
connection.Open();
SqlCeDataAdapter sqlCeDataAdapter = new SqlCeDataAdapter(sql, connection);
Stopwatch watch = new Stopwatch();
DataSet dataSet = new DataSet();
try
{
Cursor.Current = Cursors.WaitCursor;
watch.Start();
sqlCeDataAdapter.Fill(dataSet, "items");
sqlCeDataAdapter.Dispose();
var myBind = new BindingSource(dataSet, "items");
grid.DataSource = myBind;
}
finally
{
watch.Stop();
Cursor.Current = Cursors.Default;
MessageBox.Show(watch.ElapsedMilliseconds.ToString());
}
}
Load ("select a1, a2 from table");
SQL Server CE是否很长,还是应该加载更快?
我该怎么做才能让这个选择更快?
当我使用其他表的连接时,时间急剧增长……
编辑:
我已经更改了以下新版本的代码,但仍然是7.5秒. …
private void Load2 (string sql)
{
if (connection.State != System.Data.ConnectionState.Open)
{
connection.Open();
}
using (SqlCeCommand command = new SqlCeCommand(sql, connection))
{
Stopwatch watch = new Stopwatch();
Cursor.Current = Cursors.WaitCursor;
watch.Start();
using (SqlCeDataReader reader = command.ExecuteReader())
{
DataSet dataSet = new DataSet();
dataSet.Tables.Add("items");
dataSet.Tables["items"].Columns.Add("s1");
dataSet.Tables["items"].Columns.Add("s2");
while (reader.Read())
{
string s1 = reader.GetString(0);
string s2 = reader.GetString(1);
dataSet.Tables["items"].Rows.Add(s1, s2);
}
watch.Stop();
Cursor.Current = Cursors.Default;
MessageBox.Show(watch.ElapsedMilliseconds.ToString());
BindingSource binding = new BindingSource(dataSet, "items");
grid.DataSource = binding;
}
}
}
最佳答案 SqlCeDataAdapter.Fill(…)只是出了名的慢.如果您真的需要性能,则需要使用
SqlCeDataReader
.
private void Load(string sql) {
if (connection.State != System.Data.ConnectionState.Open) {
connection.Open();
}
using (SqlCeCommand command = new SqlCeCommand(sql, connection)) {
using (SqlCeDataReader reader = command.ExecuteReader()) {
DataSet dataSet = new DataSet();
dataSet.Tables.Add("items");
while (reader.Read()) {
DataRow row = dataSet.Tables["items"].NewRow();
// fill your row
dataSet.Tables["items"].Rows.Add(row);
}
BindingSource binding = new BindingSource(dataSet, "items");
grid.DataSource = binding;
}
}
}
当然,添加正确的错误处理,并根据自己的喜好进行清理.与DbDataAdapter实现相比,还有Entity Framework在性能上相当不错.
因为您使用的是SqlCe,所以您还有其他限制因素,例如磁盘IO,并且您没有服务器处理任何类型的优化的SQL事务.