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Diffstat (limited to 'user_guide/database/queries.html')
| -rw-r--r-- | user_guide/database/queries.html | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/user_guide/database/queries.html b/user_guide/database/queries.html index 685da43dc..e7333efc2 100644 --- a/user_guide/database/queries.html +++ b/user_guide/database/queries.html @@ -28,7 +28,7 @@ <div id="masthead"> <table cellpadding="0" cellspacing="0" border="0" style="width:100%"> <tr> -<td><h1>CodeIgniter User Guide Version 2.0.2</h1></td> +<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> @@ -68,23 +68,28 @@ Queries <code>$this->db->query('YOUR QUERY HERE');</code> <p>The <dfn>query()</dfn> function returns a database result <strong>object</strong> when "read" type queries are run, -which you can use to <a href="results.html">show your results</a>. When "write" type queries are run it simply returns TRUE or FALSE -depending on success or failure. When retrieving data you will typically assign the query to your own variable, like this:</p> +which you can use to <a href="results.html">show your results</a>. When "write" type queries are run it simply returns TRUE or FALSE +depending on success or failure. When retrieving data you will typically assign the query to your own variable, like this:</p> <code><var>$query</var> = $this->db->query('YOUR QUERY HERE');</code> <h2>$this->db->simple_query();</h2> -<p>This is a simplified version of the <dfn>$this->db->query()</dfn> function. It ONLY returns TRUE/FALSE on success or failure. +<p>This is a simplified version of the <dfn>$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>Adding Database prefixes manually</h1> -<p>If you have configured a database prefix and would like to add it in manually for, you can use the following.</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 /> +$this->db->dbprefix('tablename');<br /> +// outputs newprefix_tablename</code></p> + <h1>Protecting identifiers</h1> <p>In many databases it is advisable to protect table and field names - for example with backticks in MySQL. <strong>Active Record queries are automatically protected</strong>, however if you need to manually protect an identifier you can use:</p> @@ -100,16 +105,16 @@ CodeIgniter has three methods that help you do this:</p> <ol> <li><strong>$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: +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. +<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>$this->db->escape_like_str()</strong> This method should be used when strings are to be used in LIKE +<li><strong>$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 /> @@ -130,7 +135,7 @@ $this->db->query($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> +<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> |