Changes between Version 4 and Version 5 of TracReports


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Timestamp:
Oct 7, 2012 5:32:49 PM (23 months ago)
Author:
trac
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  • TracReports

    v4 v5  
     1** Note: this page documents the version 1.0 of Trac, see [[0.12/TracReports]] if you need the previous version ** 
    12= Trac Reports = 
    23[[TracGuideToc]] 
     
    6970 
    7071''Creating a custom report requires a comfortable knowledge of SQL.'' 
     72 
     73'''Note that you need to set up [TracPermissions#Reports permissions] in order to see the buttons for adding or editing reports.''' 
    7174 
    7275A report is basically a single named SQL query, executed and presented by 
     
    107110}}} 
    108111 
    109 --- 
    110112 
    111113== Advanced Reports: Dynamic Variables == 
     
    146148}}} 
    147149 
    148  
    149 ---- 
    150150 
    151151 
     
    155155specialized SQL statements to control the output of the Trac report engine. 
    156156 
    157 == Special Columns == 
     157=== Special Columns === 
    158158To format reports, TracReports looks for 'magic' column names in the query 
    159159result. These 'magic' names are processed and affect the layout and style of the  
     
    193193</div> 
    194194}}} 
    195  * '''`__style__`''' — A custom CSS style expression to use for the current row.  
     195 * '''`__style__`''' — A custom CSS style expression to use on the `<tr>` element of the current row. 
     196 * '''`__class__`''' — Zero or more space-separated CSS class names to be set on the `<tr>` element of the current row. These classes are added to the class name derived from `__color__` and the odd / even indicator. 
    196197 
    197198'''Example:''' ''List active tickets, grouped by milestone, group header linked to milestone page, colored by priority'' 
     
    248249If you have tickets in the database ''before'' you declare the extra fields in trac.ini, there will be no associated data in the ticket_custom table. To get around this, use SQL's "LEFT OUTER JOIN" clauses. See [trac:TracIniReportCustomFieldSample TracIniReportCustomFieldSample] for some examples. 
    249250 
    250 '''Note that you need to set up permissions in order to see the buttons for adding or editing reports.''' 
     251=== A note about SQL rewriting #rewriting 
     252 
     253Beyond the relatively trivial replacement of dynamic variables, the SQL query is also altered in order to support two features of the reports: 
     254 1. [#sort-order changing the sort order] 
     255 2. pagination support (limitation of the number of result rows displayed on each page) 
     256In order to support the first feature, the sort column is inserted in the `ORDER BY` clause in the first position or in the second position if a `__group__` column is specified (an `ORDER BY` clause is created if needed). In order to support pagination, a `LIMIT ... OFFSET ...` clause is appended. 
     257The query might be too complex for the automatic rewrite to work correctly, resulting in an erroneous query. In this case you still have the possibility to control exactly how the rewrite is done by manually inserting the following tokens: 
     258 - `@SORT_COLUMN@`, the place where the name of the selected sort column will be inserted, 
     259 - `@LIMIT_OFFSET@`, the place where the pagination support clause will be added 
     260Note that if you write them after an SQL comment, `--`, you'll effectively disable rewriting if this is what you want! 
     261 
     262Let's take an example, consider the following SQL query: 
     263{{{ 
     264-- ## 4: Assigned, Active Tickets by Owner ## -- 
     265 
     266--  
     267-- List assigned tickets, group by ticket owner, sorted by priority. 
     268--  
     269 
     270SELECT p.value AS __color__, 
     271   owner AS __group__, 
     272   id AS ticket, summary, component, milestone, t.type AS type, severity, time AS created, 
     273   changetime AS _changetime, description AS _description, 
     274   reporter AS _reporter 
     275  FROM ticket t,enum p 
     276  WHERE status = 'assigned' 
     277AND p.name=t.priority AND p.type='priority' 
     278  ORDER BY __group__, p.value, severity, time 
     279}}} 
     280 
     281The automatic rewrite will be the following (4 rows per page, page 2, sorted by `component`): 
     282{{{ 
     283SELECT p.value AS __color__, 
     284   owner AS __group__, 
     285   id AS ticket, summary, component, milestone, t.type AS type, severity, time AS created, 
     286   changetime AS _changetime, description AS _description, 
     287   reporter AS _reporter 
     288  FROM ticket t,enum p 
     289  WHERE status = 'assigned' 
     290AND p.name=t.priority AND p.type='priority' 
     291  ORDER BY __group__ ASC, `component` ASC,  __group__, p.value, severity, time 
     292 LIMIT 4 OFFSET 4 
     293}}} 
     294 
     295The equivalent SQL query with the rewrite tokens would have been: 
     296{{{ 
     297SELECT p.value AS __color__, 
     298   owner AS __group__, 
     299   id AS ticket, summary, component, milestone, t.type AS type, severity, time AS created, 
     300   changetime AS _changetime, description AS _description, 
     301   reporter AS _reporter 
     302  FROM ticket t,enum p 
     303  WHERE status = 'assigned' 
     304AND p.name=t.priority AND p.type='priority' 
     305  ORDER BY __group__, @SORT_COLUMN@, p.value, severity, time 
     306@LIMIT_OFFSET@ 
     307}}} 
     308 
     309If you want to always sort first by priority and only then by the user selected sort column, simply use the following `ORDER BY` clause: 
     310{{{ 
     311  ORDER BY __group__, p.value, @SORT_COLUMN@, severity, time 
     312}}} 
    251313 
    252314----