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Overview
Comment:Fix typo in the RANGE documentation of windows functions.
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SHA3-256: 463da73728db95b3fd67f43450a9f572d7b9d894de2b628dc075a81a7ae91bd9
User & Date: drh 2018-07-05 21:13:53.668
Context
2018-07-06
18:30
Update the syntax diagrams to include the new window function syntax. (check-in: f7a6a2f7c2 user: drh tags: trunk)
2018-07-05
21:13
Fix typo in the RANGE documentation of windows functions. (check-in: 463da73728 user: drh tags: trunk)
2018-07-02
08:00
Add a sentence to the FTS3/4 documentation to make it clear that only columns that are part of the FTS3/4 table declaration exist, even if an external content table with more columns is in use. (check-in: ea0f0b4c4a user: dan tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to pages/windowfunctions.in.
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previous row ("1 PRECEDING") and the following row ("1 FOLLOWING"), inclusive,
where rows are sorted according to the ORDER BY clause in the
<i>&lt;window-definition&gt;</i> (in this case "ORDER BY a"). For example, the frame for the row with (a=3) consists of rows (2, 'B', 'two'), (3, 'C', 'three') and (4, 'D', 'one'). The result of group_concat(b, '.') for that row is therefore 'B.C.D'.

<p> The default <i>&lt;frame-specification&gt;</i> is:

<codeblock>
    RANGE BETWEEN UNBOUNDED PRECEDING TO CURRENT ROW
</codeblock>

<p> This means that, after sorting the rows returned by the SELECT according to
the ORDER BY clause in the &lt;window-definition&gt;, the window frame consists
of all rows between the first row and the last row with the same values as the current row for all ORDER BY expressions. This implies that rows that have the same values for all ORDER BY expressions will also have the same value for the result of the window function (as the window frame is the same). For example:

<codeblock>








|








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previous row ("1 PRECEDING") and the following row ("1 FOLLOWING"), inclusive,
where rows are sorted according to the ORDER BY clause in the
<i>&lt;window-definition&gt;</i> (in this case "ORDER BY a"). For example, the frame for the row with (a=3) consists of rows (2, 'B', 'two'), (3, 'C', 'three') and (4, 'D', 'one'). The result of group_concat(b, '.') for that row is therefore 'B.C.D'.

<p> The default <i>&lt;frame-specification&gt;</i> is:

<codeblock>
    RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
</codeblock>

<p> This means that, after sorting the rows returned by the SELECT according to
the ORDER BY clause in the &lt;window-definition&gt;, the window frame consists
of all rows between the first row and the last row with the same values as the current row for all ORDER BY expressions. This implies that rows that have the same values for all ORDER BY expressions will also have the same value for the result of the window function (as the window frame is the same). For example:

<codeblock>
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  <li> <b>xInverse(5)</b> - remove value "5" from the window.
  <li> <b>xStep(1)</b> - add value "1" to the window.
  <li> <b>xValue()</b> - invoked to obtain the value for row (x='d').
  <li> <b>xInverse(3)</b> - remove value "3" from the window. The window now
       contains values 8 and 1 only.
  <li> <b>xValue()</b> - invoked to obtain the value for row (x='d'). 9.
</ol>










<
<

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  <li> <b>xInverse(5)</b> - remove value "5" from the window.
  <li> <b>xStep(1)</b> - add value "1" to the window.
  <li> <b>xValue()</b> - invoked to obtain the value for row (x='d').
  <li> <b>xInverse(3)</b> - remove value "3" from the window. The window now
       contains values 8 and 1 only.
  <li> <b>xValue()</b> - invoked to obtain the value for row (x='d'). 9.
</ol>