[轉貼][心得]太多的DataView過濾效能不佳

[tomex (tomex_ou)]

I have a DataTable which contains 1545 rows. I have a method that returns a
DataTable of distinct rows based on one column. This table ends up with 386
rows.

I need to loop through the smaller table and filter a DataView based on each
row from this table.
This loops takes ~5 secs. Is there anyway to improve this?

DataTable dt = SelectDistinctValues(...); // returns a table with 386 rows
foreach (DataRow dr in dt.Rows)
{

  dv.RowFilter = string.Format("value = '{0}'", dr[0].ToString() );

  foreach (DataRowView drv in dv)
  {
  ...
  }
}


Answer:
Yes there is a much better way to do this.

Let me understand your problem first - You have two tables. One contains
distinct values but it was formed out of the first.

Instead of recreating a dataview everytime the user selects a row from the
distinct table, use the relation and use GetChildRows instead. That's MUCH
MUCH faster.

Reference:
http://0rz.net/cf1jx

GetChildRows/Relation sample:
http://www.c-sharpcorner.com/asp/Articles/MasterDetailDCHK.asp

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