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Pascal Kriete1f622292011-04-07 12:06:51 -0400[diff] [blame]31<td><h1>CodeIgniter User Guide Version 2.0.2</h1></td>
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]32<td id="breadcrumb_right"><a href="../toc.html">Table of Contents Page</a></td>
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62<h1>Queries</h1>
63
64<h2>$this->db->query();</h2>
65
66<p>To submit a query, use the following function:</p>
67
68<code>$this->db->query('YOUR QUERY HERE');</code>
69
70<p>The <dfn>query()</dfn> function returns a database result <strong>object</strong> when "read" type queries are run,
Razican114ab092011-04-25 17:26:45 +0200[diff] [blame^]71which you can use to <a href="results.html">show your results</a>. When "write" type queries are run it simply returns TRUE or FALSE
72depending on success or failure. When retrieving data you will typically assign the query to your own variable, like this:</p>
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]73
74<code><var>$query</var> = $this->db->query('YOUR QUERY HERE');</code>
75
76<h2>$this->db->simple_query();</h2>
77
Razican114ab092011-04-25 17:26:45 +0200[diff] [blame^]78<p>This is a simplified version of the <dfn>$this->db->query()</dfn> function. It ONLY returns TRUE/FALSE on success or failure.
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]79It DOES NOT return a database result set, nor does it set the query timer, or compile bind data, or store your query for debugging.
80It simply lets you submit a query. Most users will rarely use this function.</p>
81
82
83<h1>Adding Database prefixes manually</h1>
84<p>If you have configured a database prefix and would like to add it in manually for, you can use the following.</p>
85<p><code>$this-&gt;db-&gt;dbprefix('tablename');<br />
86// outputs prefix_tablename</code></p>
87
88
89<h1>Protecting identifiers</h1>
90<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>
91<p><code>$this-&gt;db-&gt;protect_identifiers('table_name');</code></p>
92
93<p>This function will also add a table prefix to your table, assuming you have a prefix specified in your database config file. To enable the prefixing set <kbd>TRUE</kbd> (boolen) via the second parameter:</p>
94<p><code>$this-&gt;db-&gt;protect_identifiers('table_name', <kbd>TRUE</kbd>);</code></p>
95
96
97<h1>Escaping Queries</h1>
98<p>It's a very good security practice to escape your data before submitting it into your database.
Derek Jonese4ed5832009-02-20 21:44:59 +0000[diff] [blame]99CodeIgniter has three methods that help you do this:</p>
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]100
101<ol>
102<li><strong>$this->db->escape()</strong> This function determines the data type so that it
Razican114ab092011-04-25 17:26:45 +0200[diff] [blame^]103can escape only string data. It also automatically adds single quotes around the data so you don't have to:
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]104
105<code>$sql = "INSERT INTO table (title) VALUES(".$this->db->escape($title).")";</code></li>
106
Razican114ab092011-04-25 17:26:45 +0200[diff] [blame^]107<li><strong>$this->db->escape_str()</strong> This function escapes the data passed to it, regardless of type.
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]108Most of the time you'll use the above function rather than this one. Use the function like this:
109
110<code>$sql = "INSERT INTO table (title) VALUES('".$this->db->escape_str($title)."')";</code></li>
Derek Jonese4ed5832009-02-20 21:44:59 +0000[diff] [blame]111
Razican114ab092011-04-25 17:26:45 +0200[diff] [blame^]112<li><strong>$this->db->escape_like_str()</strong> This method should be used when strings are to be used in LIKE
Derek Jonese4ed5832009-02-20 21:44:59 +0000[diff] [blame]113conditions so that LIKE wildcards ('%', '_') in the string are also properly escaped.
114
115<code>$search = '20% raise';<br />
Derek Allardf597dd12010-07-05 07:43:46 -0400[diff] [blame]116$sql = "SELECT id FROM table WHERE column LIKE '%".$this->db->escape_like_str($search)."%'";</code></li>
Derek Jonese4ed5832009-02-20 21:44:59 +0000[diff] [blame]117
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]118</ol>
119
120
121<h1>Query Bindings</h1>
122
123
124<p>Bindings enable you to simplify your query syntax by letting the system put the queries together for you. Consider the following example:</p>
125
126<code>
127$sql = "SELECT * FROM some_table WHERE id = <var>?</var> AND status = <var>?</var> AND author = <var>?</var>";
128<br /><br />
129$this->db->query($sql, array(3, 'live', 'Rick'));
130</code>
131
132<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>
Razican114ab092011-04-25 17:26:45 +0200[diff] [blame^]133<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>
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]134
Barry Mienydd671972010-10-04 16:33:58 +0200[diff] [blame]135
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]136
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Derek Jones898949f2011-01-28 07:42:16 -0600[diff] [blame]149<p><a href="http://codeigniter.com">CodeIgniter</a> &nbsp;&middot;&nbsp; Copyright &#169; 2006 - 2011 &nbsp;&middot;&nbsp; <a href="http://ellislab.com/">EllisLab, Inc.</a></p>
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