DataTable How to conditionally delete rows

Question

I m engaged in a C  learning process and it is going well so far  I however just now hit my first  say what   moment   The DataTable offers random row access to its Rows collection  not only through typical collections behavior  but also through DataTable Select  However I cannot seem to be able to tie this ability to DataRow Delete  So far this is what it seems I need to do in order to conditionally delete one or more rows from a table   int max   someDataTable Rows Count - 1  for int i   max  i  gt   0  --i        if  int someDataTable Rows i  ItemArray 0     someValue                someDataTable Rows i  BeginEdit            someDataTable Rows i  Delete              else         break    someDataTable AcceptChanges      But I m not happy with this code  Neither I m convinced  I must be missing something  Am I really forced to hit the Rows collection sequentially if I need to delete one or more rows conditionally    don t mind the inverted for  I m deleting from the end of the datatable  So it s ok

User · Answer

Here s a one-liner using LINQ and avoiding any run-time evaluation of select strings   someDataTable Rows Cast lt DataRow gt    Where      r   gt  r ItemArray 0     someValue  ToList   ForEach r   gt  r Delete

User · Answer

Extension method based on Linq  public static void DeleteRows this DataTable dt  Func lt DataRow  bool gt  predicate        foreach  var row in dt Rows Cast lt DataRow gt    Where predicate  ToList            row Delete        Then use   DataTable dt   GetSomeData    dt DeleteRows r   gt  r Field lt double gt   Amount    gt  123 12  amp  amp  r Field lt string gt   ABC       XYZ

User · Answer

I don t have a windows box handy to try this but I think you can use a DataView and do something like so   DataView view   new DataView ds Tables  MyTable     view RowFilter    MyValue   42      MyValue here is a column name     Delete these rows  foreach  DataRowView row in view      row Delete        I haven t tested this  though   You might give it a try

User · Answer

You could query the dataset and then loop the selected rows to set them as delete   var rows   dt Select  col1  gt  5    foreach  var row in rows      row Delete          and you could also create some extension methods to make it easier      myTable Delete  col1  gt  5     public static DataTable Delete this DataTable table  string filter        table Select filter  Delete        return table    public static void Delete this IEnumerable lt DataRow gt  rows        foreach  var row in rows          row Delete

[c#] DataTable, How to conditionally delete rows

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