Changes between Version 3 and Version 4 of DygraphsVisualizationPlugin

Timestamp:

Jun 22, 2015, 7:14:11 PM (9 years ago)

Author:

Jon Ashley

Comment:

Add a simpler example query, for plotting the number of open and closed tickets over time

DygraphsVisualizationPlugin

@@ -54 +54 @@
 == Example graphs
 
-=== Report the number of open tickets with particular values of a custom field over time
+=== Report the history of tickets open and closed
 
 It's often useful to be able to generate reports that span a period of time, for monitoring the progress of a project.
 
-Constructing such reports is not always straightforward. Here's an example of a report that looks for tickets of type 'fault' that have a custom field 'safety_related'. At any time, this field can have one of three values that classify the safety status of the ticket: 'Not assessed', 'Safety related' or 'Not safety related'. The report plots the count of the number of open tickets with each safety status at the start of every week for the past three years.
+Constructing such reports is not always straightforward. Here's an example of a report that plots the number of tickets that were opened and closed throughout the duration of the project. It also plots the growth of the "backlog": the number of currently-open tickets at that time.
 
 Note that this query uses Common Table Expressions. These have only been present in SQLite since [[http://www.sqlite.org/releaselog/3_8_3.html|version 3.8.3]]. It will usually be necessary to update the version of `SQLITE3.DLL` in your Python installation's top-level `DLLs` folder to one compiled from SQLite 3.8.3 or later.
+
+{{{
+#!sql
+WITH
+  cutoff_time(n, usec) AS
+    -- January 1 1970 was a Thursday.
+    -- We want to break at midnight between Sunday and Monday,
+    -- which is why there is a 3-day offset in the timestamps calculation.
+    (SELECT 0, 1e6 * (strftime('%s', 'now') -
+               ((strftime('%s', 'now') + (86400 * 3)) % (86400 * 7)))
+     UNION ALL
+     SELECT n + 1, usec - (1e6 * 86400 * 7) FROM cutoff_time LIMIT 520),
+
+  -- The following line stops Trac from limiting the output displayed
+  -- on a single page (leave it in as a comment to do this):
+  -- @LIMIT_OFFSET@
+  -- I don't think it works with Trac prior to version 1.0 though.
+
+  open_time(id, usec) AS
+    (SELECT id, time FROM ticket),
+
+  close_time(id, usec) AS
+    (SELECT ticket, MAX(time)
+     FROM ticket_change
+     WHERE field = 'status' AND newvalue = 'closed'
+     GROUP BY ticket),
+
+  num_closed(n, cnt) AS
+    (SELECT n, COUNT(id)
+     FROM cutoff_time
+     JOIN close_time ON cutoff_time.usec > close_time.usec
+     GROUP BY n),
+
+  num_opened(n, cnt) AS
+    (SELECT n, COUNT(id)
+     FROM cutoff_time
+     JOIN open_time ON cutoff_time.usec > open_time.usec
+     GROUP BY n)
+
+SELECT
+  date(cutoff_time.usec / 1e6, 'unixepoch') AS 'Date',
+  num_opened.cnt - IFNULL(num_closed.cnt, 0) AS 'Backlog',
+  num_opened.cnt AS 'Opened',
+  IFNULL(num_closed.cnt, 0) AS 'Closed'
+  FROM cutoff_time
+  JOIN num_opened USING (n)
+  LEFT OUTER JOIN num_closed USING (n)
+  ORDER BY date
+}}}
+
+=== Report the number of open tickets with particular values of a custom field over time
+
+Here's a more complex report that looks for tickets of type 'fault' that have a custom field 'safety_related'. At any time, this field can have one of three values that classify the safety status of the ticket: 'Not assessed', 'Safety related' or 'Not safety related'. The report plots the count of the number of open tickets with each safety status at the start of every week for the past three years.
 
 {{{
@@ -68 +121 @@
   -- Includes a prediction of the status at the start of next week.
   period(n) AS
-    -- January 1 1970 was a Thursday.
-    -- To break periods at midnight between Sunday and Monday,
-    -- a 3-day offset is placed in the timestamps calculation.
     (SELECT (strftime('%s', 'now') + (86400 * 7) -
                ((strftime('%s', 'now') + (86400 * 3)) % (86400 * 7)))
@@ -76 +126 @@
      SELECT n - (86400 * 7) FROM period LIMIT 156),
 
-  -- The following line stops Trac from limiting the output displayed
-  -- on a single page (leave it in as a comment to do this):
   -- @LIMIT_OFFSET@
-  -- I don't think it works with Trac prior to version 1.0 though.
 
   -- Restrict query to a particular subset of tickets here: