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Comment:Fix typos in the windowfunctions.html document.
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SHA3-256: 221cce4209f950a4b91372aed71f477daf883e7acfb981295d22502dbc40fc21
User & Date: drh 2018-09-12 10:49:36.651
Context
2018-09-13
12:50
Updates to the geopoly documentation. (check-in: f1742a52f5 user: drh tags: trunk)
2018-09-12
10:49
Fix typos in the windowfunctions.html document. (check-in: 221cce4209 user: drh tags: trunk)
2018-09-11
22:44
Fix typos in the geopoly document. (check-in: 81cf14c724 user: drh tags: trunk)
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Changes to pages/windowfunctions.in.
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presence of an OVER clause.  If a function invocation has an OVER clause
then it is a window function, and if lacks a OVER clause it is an ordinary
function.  Window functions might also have a FILTER
clause in between the function and the OVER clause.

<p>Unlike ordinary functions, window functions
cannot use the DISTINCT keyword.
Also, Window functions may only appears in the result set and in the
ORDER BY clause of a SELECT statement.

<p>The following simple table is used to demonstrate how window
functions work:

<codeblock>
  CREATE TABLE t0(x INTEGER PRIMARY KEY, y TEXT);








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presence of an OVER clause.  If a function invocation has an OVER clause
then it is a window function, and if lacks a OVER clause it is an ordinary
function.  Window functions might also have a FILTER
clause in between the function and the OVER clause.

<p>Unlike ordinary functions, window functions
cannot use the DISTINCT keyword.
Also, Window functions may only appear in the result set and in the
ORDER BY clause of a SELECT statement.

<p>The following simple table is used to demonstrate how window
functions work:

<codeblock>
  CREATE TABLE t0(x INTEGER PRIMARY KEY, y TEXT);
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       non-negative integer. In this case the value returned is the result
       of evaluating <i>expr</i> against the row <i>offset</i> rows before the
       current row within the partition. If <i>offset</i> is 0, then
       <i>expr</i> is evaluated against the current row. If there is no row
       <i>offset</i> rows before the current row, NULL is returned.

      <p> If <i>default</i> is also provided, then it is returned instead of
      NULL if row identified by <i>offset</i> does not exist.
       
  <dt><p><b>lead(expr)<br>lead(expr, offset)<br>lead(expr, offset, default)</b>
  <dd><p> The first form of the lead() function returns the result of evaluating
       expression <i>expr</i> against the next row in the partition. Or, if
       there is no next row (because the current row is the last), NULL.

      <p> If the <i>offset</i> argument is provided, then it must be a
       non-negative integer. In this case the value returned is the result
       of evaluating <i>expr</i> against the row <i>offset</i> rows after the
       current row within the partition. If <i>offset</i> is 0, then
       <i>expr</i> is evaluated against the current row. If there is no row
       <i>offset</i> rows after the current row, NULL is returned.

      <p> If <i>default</i> is also provided, then it is returned instead of
      NULL if row identified by <i>offset</i> does not exist.
  <dt><p><b>first_value(expr)</b>
  <dd><p> This built-in window function calculates the window frame for each
       row in the same way as an aggregate window function. It returns the
       value of <i>expr</i> evaluated against the first row in the window frame
       for each row.
  <dt><p><b>last_value(expr)</b>
  <dd><p> This built-in window function calculates the window frame for each








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       non-negative integer. In this case the value returned is the result
       of evaluating <i>expr</i> against the row <i>offset</i> rows before the
       current row within the partition. If <i>offset</i> is 0, then
       <i>expr</i> is evaluated against the current row. If there is no row
       <i>offset</i> rows before the current row, NULL is returned.

      <p> If <i>default</i> is also provided, then it is returned instead of
      NULL if the row identified by <i>offset</i> does not exist.
       
  <dt><p><b>lead(expr)<br>lead(expr, offset)<br>lead(expr, offset, default)</b>
  <dd><p> The first form of the lead() function returns the result of evaluating
       expression <i>expr</i> against the next row in the partition. Or, if
       there is no next row (because the current row is the last), NULL.

      <p> If the <i>offset</i> argument is provided, then it must be a
       non-negative integer. In this case the value returned is the result
       of evaluating <i>expr</i> against the row <i>offset</i> rows after the
       current row within the partition. If <i>offset</i> is 0, then
       <i>expr</i> is evaluated against the current row. If there is no row
       <i>offset</i> rows after the current row, NULL is returned.

      <p> If <i>default</i> is also provided, then it is returned instead of
      NULL if the row identified by <i>offset</i> does not exist.
  <dt><p><b>first_value(expr)</b>
  <dd><p> This built-in window function calculates the window frame for each
       row in the same way as an aggregate window function. It returns the
       value of <i>expr</i> evaluated against the first row in the window frame
       for each row.
  <dt><p><b>last_value(expr)</b>
  <dd><p> This built-in window function calculates the window frame for each
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