[ROOT] TTree::Scan Distinct-option

From: Bernd Reinhold (Bernd.Reinhold@cern.ch)
Date: Mon Jun 28 2004 - 13:50:21 MEST


I'm filling a TTree from a SQL-recordset. This made me wonder, if there are
some options in TTree, that exist in SQL:
1. TTree::Scan("column1"); returns me all values of column1. Is there an
option "DISTINCT", which returns each value in column1 exactly once?
2. Is there something like a "LIKE"-function for the selector in
TTree::Draw? If column1 is of type C-string. Then I might want to have all
the entries, whose column1 starts with "AB". In SQL one could use something
like: "column1 like \"AB%\"" Is something like that possible in a
3. Is there a GROUP BY-clause (along with some basic aggregate-functions:
avg, std, min, max, count), when you think of the selector as the

Thank you,


This archive was generated by hypermail 2b29 : Sun Jan 02 2005 - 05:50:08 MET