diff options
| author | Joël Cox <joel@joelcox.nl> | 2011-10-09 18:39:39 +0200 |
|---|---|---|
| committer | Joël Cox <joel@joelcox.nl> | 2011-10-09 18:39:39 +0200 |
| commit | f4fb1db458fab52d0493ead52c9ea7e01206eaa7 (patch) | |
| tree | c549600f342f4d3f0df75a2f2f7c265be0f1cc72 /user_guide/database/queries.html | |
| parent | c4dd200c1155a118afa32cd91d9bd67bc243f83a (diff) | |
Moved tutorial to new user guide directory.
Diffstat (limited to 'user_guide/database/queries.html')
| -rw-r--r-- | user_guide/database/queries.html | 158 |
1 files changed, 0 insertions, 158 deletions
diff --git a/user_guide/database/queries.html b/user_guide/database/queries.html deleted file mode 100644 index e7333efc2..000000000 --- a/user_guide/database/queries.html +++ /dev/null @@ -1,158 +0,0 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> -<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> -<head> - -<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> -<title>Queries : CodeIgniter User Guide</title> - -<style type='text/css' media='all'>@import url('../userguide.css');</style> -<link rel='stylesheet' type='text/css' media='all' href='../userguide.css' /> - -<script type="text/javascript" src="../nav/nav.js"></script> -<script type="text/javascript" src="../nav/prototype.lite.js"></script> -<script type="text/javascript" src="../nav/moo.fx.js"></script> -<script type="text/javascript" src="../nav/user_guide_menu.js"></script> - -<meta http-equiv='expires' content='-1' /> -<meta http-equiv= 'pragma' content='no-cache' /> -<meta name='robots' content='all' /> -<meta name='author' content='ExpressionEngine Dev Team' /> -<meta name='description' content='CodeIgniter User Guide' /> - -</head> -<body> - -<!-- START NAVIGATION --> -<div id="nav"><div id="nav_inner"><script type="text/javascript">create_menu('../');</script></div></div> -<div id="nav2"><a name="top"></a><a href="javascript:void(0);" onclick="myHeight.toggle();"><img src="../images/nav_toggle_darker.jpg" width="154" height="43" border="0" title="Toggle Table of Contents" alt="Toggle Table of Contents" /></a></div> -<div id="masthead"> -<table cellpadding="0" cellspacing="0" border="0" style="width:100%"> -<tr> -<td><h1>CodeIgniter User Guide Version 2.0.3</h1></td> -<td id="breadcrumb_right"><a href="../toc.html">Table of Contents Page</a></td> -</tr> -</table> -</div> -<!-- END NAVIGATION --> - - -<!-- START BREADCRUMB --> -<table cellpadding="0" cellspacing="0" border="0" style="width:100%"> -<tr> -<td id="breadcrumb"> -<a href="http://codeigniter.com/">CodeIgniter Home</a> › -<a href="../index.html">User Guide Home</a> › -<a href="index.html">Database Library</a> › -Queries -</td> -<td id="searchbox"><form method="get" action="http://www.google.com/search"><input type="hidden" name="as_sitesearch" id="as_sitesearch" value="codeigniter.com/user_guide/" />Search User Guide <input type="text" class="input" style="width:200px;" name="q" id="q" size="31" maxlength="255" value="" /> <input type="submit" class="submit" name="sa" value="Go" /></form></td> -</tr> -</table> -<!-- END BREADCRUMB --> - - - -<br clear="all" /> - - -<!-- START CONTENT --> -<div id="content"> - - -<h1>Queries</h1> - -<h2>$this->db->query();</h2> - -<p>To submit a query, use the following function:</p> - -<code>$this->db->query('YOUR QUERY HERE');</code> - -<p>The <dfn>query()</dfn> function returns a database result <strong>object</strong> when "read" type queries are run, -which you can use to <a href="results.html">show your results</a>. When "write" type queries are run it simply returns TRUE or FALSE -depending on success or failure. When retrieving data you will typically assign the query to your own variable, like this:</p> - -<code><var>$query</var> = $this->db->query('YOUR QUERY HERE');</code> - -<h2>$this->db->simple_query();</h2> - -<p>This is a simplified version of the <dfn>$this->db->query()</dfn> function. It ONLY returns TRUE/FALSE on success or failure. -It DOES NOT return a database result set, nor does it set the query timer, or compile bind data, or store your query for debugging. -It simply lets you submit a query. Most users will rarely use this function.</p> - - -<h1>Working with Database prefixes manually</h1> -<p>If you have configured a database prefix and would like to prepend it to a table name for use in a native SQL query for example, then you can use the following:</p> -<p><code>$this->db->dbprefix('tablename');<br /> -// outputs prefix_tablename</code></p> - -<p>If for any reason you would like to change the prefix programatically without needing to create a new connection, you can use this method:</p> -<p><code>$this->db->set_dbprefix('newprefix');<br /><br /> -$this->db->dbprefix('tablename');<br /> -// outputs newprefix_tablename</code></p> - - -<h1>Protecting identifiers</h1> -<p>In many databases it is advisable to protect table and field names - for example with backticks in MySQL. <strong>Active Record queries are automatically protected</strong>, however if you need to manually protect an identifier you can use:</p> -<p><code>$this->db->protect_identifiers('table_name');</code></p> - -<p>This function will also add a table prefix to your table, assuming you have a prefix specified in your database config file. To enable the prefixing set <kbd>TRUE</kbd> (boolen) via the second parameter:</p> -<p><code>$this->db->protect_identifiers('table_name', <kbd>TRUE</kbd>);</code></p> - - -<h1>Escaping Queries</h1> -<p>It's a very good security practice to escape your data before submitting it into your database. -CodeIgniter has three methods that help you do this:</p> - -<ol> -<li><strong>$this->db->escape()</strong> This function determines the data type so that it -can escape only string data. It also automatically adds single quotes around the data so you don't have to: - -<code>$sql = "INSERT INTO table (title) VALUES(".$this->db->escape($title).")";</code></li> - -<li><strong>$this->db->escape_str()</strong> This function escapes the data passed to it, regardless of type. -Most of the time you'll use the above function rather than this one. Use the function like this: - -<code>$sql = "INSERT INTO table (title) VALUES('".$this->db->escape_str($title)."')";</code></li> - -<li><strong>$this->db->escape_like_str()</strong> This method should be used when strings are to be used in LIKE -conditions so that LIKE wildcards ('%', '_') in the string are also properly escaped. - -<code>$search = '20% raise';<br /> -$sql = "SELECT id FROM table WHERE column LIKE '%".$this->db->escape_like_str($search)."%'";</code></li> - -</ol> - - -<h1>Query Bindings</h1> - - -<p>Bindings enable you to simplify your query syntax by letting the system put the queries together for you. Consider the following example:</p> - -<code> -$sql = "SELECT * FROM some_table WHERE id = <var>?</var> AND status = <var>?</var> AND author = <var>?</var>"; -<br /><br /> -$this->db->query($sql, array(3, 'live', 'Rick')); -</code> - -<p>The question marks in the query are automatically replaced with the values in the array in the second parameter of the query function.</p> -<p class="important">The secondary benefit of using binds is that the values are automatically escaped, producing safer queries. You don't have to remember to manually escape data; the engine does it automatically for you.</p> - - - -</div> -<!-- END CONTENT --> - - -<div id="footer"> -<p> -Previous Topic: <a href="connecting.html">Connecting to your Database</a> - · -<a href="#top">Top of Page</a> · -<a href="../index.html">User Guide Home</a> · -Next Topic: <a href="results.html">Query Results</a> -</p> -<p><a href="http://codeigniter.com">CodeIgniter</a> · Copyright © 2006 - 2011 · <a href="http://ellislab.com/">EllisLab, Inc.</a></p> -</div> - -</body> -</html>
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