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Overview
Comment:Enhance the C/C++ documentation to clarify the meaning of the return value from sqlite_changes(). Ticket #383. (CVS 1048)
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SHA1: 303b2da1acd4b7b9d89dec0653e5f88fc10d56b8
User & Date: drh 2003-07-08 23:42:25.000
Context
2003-07-09
00:28
Allow the output arguments in sqlite_compile and sqlite_step to be NULL pointers. Tickets #384 and #385. (CVS 1049) (check-in: dd84f88f6c user: drh tags: trunk)
2003-07-08
23:42
Enhance the C/C++ documentation to clarify the meaning of the return value from sqlite_changes(). Ticket #383. (CVS 1048) (check-in: 303b2da1ac user: drh tags: trunk)
2003-07-07
10:47
A proported fix for ticket #374. (CVS 1047) (check-in: a49ee69e98 user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to www/c_interface.tcl. 
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#
# Run this Tcl script to generate the sqlite.html file.
#
set rcsid {$Id: c_interface.tcl,v 1.37 2003/03/01 19:45:35 drh Exp $}

puts {<html>
<head>
  <title>The C language interface to the SQLite library</title>
</head>
<body bgcolor=white>
<h1 align=center>




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#
# Run this Tcl script to generate the sqlite.html file.
#
set rcsid {$Id: c_interface.tcl,v 1.38 2003/07/08 23:42:25 drh Exp $}

puts {<html>
<head>
  <title>The C language interface to the SQLite library</title>
</head>
<body bgcolor=white>
<h1 align=center>
︙︙
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the key is automatically generated.  You can find the value of the key
for the most recent INSERT statement using the
<b>sqlite_last_insert_rowid</b> API function.</p>

<h3>3.2 The number of rows that changed</h3>

<p>The <b>sqlite_changes</b> API function returns the number of rows
that were inserted, deleted, or modified during the most recent

<b>sqlite_exec</b> call of by <b>sqlite_step</b> calls since the










most recent <b>sqlite_compile</b>.  The number reported includes any changes
that were later undone by a ROLLBACK or ABORT.  But rows that are
deleted because of a DROP TABLE are <em>not</em> counted.</p>

<p>SQLite implements the command "<b>DELETE FROM table</b>" (without
a WHERE clause) by dropping the table then recreating it.  
This is much faster than deleting the elements of the table individually.
But it also means that the value returned from <b>sqlite_changes</b>








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the key is automatically generated.  You can find the value of the key
for the most recent INSERT statement using the
<b>sqlite_last_insert_rowid</b> API function.</p>

<h3>3.2 The number of rows that changed</h3>

<p>The <b>sqlite_changes</b> API function returns the number of rows
that have been inserted, deleted, or modified since the database was
last quiescent.  A "quiescent" database is one in which there are
no outstanding calls to <b>sqlite_exec</b> and no VMs created by
<b>sqlite_compile</b> that have not been finalized by <b>sqlite_finalize</b>.
In common usage, <b>sqlite_changes</b> returns the number
of rows inserted, deleted, or modified by the most recent <b>sqlite_exec</b>
call or since the most recent <b>sqlite_compile</b>.  But if you have
nested calls to <b>sqlite_exec</b> (that is, if the callback routine
of one <b>sqlite_exec</b> invokes another <b>sqlite_exec</b>) or if
you invoke <b>sqlite_compile</b> to create a new VM while there is
still another VM in existance, then
the meaning of the number returned by <b>sqlite_changes</b> is more
complex.
The number reported includes any changes
that were later undone by a ROLLBACK or ABORT.  But rows that are
deleted because of a DROP TABLE are <em>not</em> counted.</p>

<p>SQLite implements the command "<b>DELETE FROM table</b>" (without
a WHERE clause) by dropping the table then recreating it.  
This is much faster than deleting the elements of the table individually.
But it also means that the value returned from <b>sqlite_changes</b>
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