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<a href="lang.html">
           <h2 align="center">SQL As Understood By SQLite</h2></a><h1>UPDATE</h1><h4><a href="syntaxdiagrams.html#update-stmt">update-stmt:</a></h4><blockquote> <img alt="syntax diagram update-stmt" src="images/syntax/update-stmt.gif"></img> </blockquote>
<h4><a href="syntaxdiagrams.html#qualified-table-name">qualified-table-name:</a></h4><blockquote> <img alt="syntax diagram qualified-table-name" src="images/syntax/qualified-table-name.gif"></img> </blockquote>


<p>The UPDATE statement is used to change the value of columns in 
selected rows of a table.  Each assignment in an UPDATE specifies
a column name to the left of the equals sign and an arbitrary expression
to the right.  The expressions may use the values of other columns.
All expressions are evaluated before any assignments are made.
A WHERE clause can be used to restrict which rows are updated.</p>

<p>The optional conflict-clause allows the specification of an alternative
constraint conflict resolution algorithm to use during this one command.
See the section titled
<a href="lang_conflict.html">ON CONFLICT</a> for additional information.</p>

<h3>Restrictions on UPDATE Statements Within CREATE TRIGGER</h3>

<p>There are additional syntax restrictions on UPDATE statements that
occur within the body of a <a href="lang_createtrigger.html">CREATE TRIGGER</a> statement.  The <i>table-name</i>
must be unqualified. 
In other words, the <i>database-name</i><b>.</b> prefix
on the table name is not allowed within triggers. 
The table to be modified must be in the same
database as the table to which the trigger is attached.</p>

<p>The INDEXED BY and NOT INDEXED clauses are not allowed on UPDATE
statements within triggers.</p>

<p>The LIMIT clause (described below) is unsupported within triggers.</p>

<h3>Optional LIMIT and ORDER BY Clauses</h3>

<p>If SQLite is built with the <a href="compile.html#enable_update_delete_limit">SQLITE_ENABLE_UPDATE_DELETE_LIMIT</a>
compile-time option then the syntax of the UPDATE statement is extended
with optional ORDER BY and LIMIT clauses as follows:</p>

<h4><a href="syntaxdiagrams.html#update-stmt-limited">update-stmt-limited:</a></h4><blockquote> <img alt="syntax diagram update-stmt-limited" src="images/syntax/update-stmt-limited.gif"></img> </blockquote>


<p>The optional LIMIT clause can be used to limit the number of
rows modifed, and thereby limit the size of the transaction.
The ORDER BY clause is used only to determine which rows fall
within the LIMIT.  The order in which rows are modified is arbitrary
and is not determined by the ORDER BY clause.</p>