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163 lines
5.2 KiB
163 lines
5.2 KiB
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<td><h1>CodeIgniter User Guide Version 2.1.3</h1></td> |
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<td id="breadcrumb_right"><a href="../toc.html">Table of Contents Page</a></td> |
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<a href="http://codeigniter.com/">CodeIgniter Home</a> › |
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<a href="../index.html">User Guide Home</a> › |
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<a href="index.html">Database Library</a> › |
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Field Names |
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<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> |
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<h1>Field Data</h1> |
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<h2>$this->db->list_fields()</h2> |
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<p>Returns an array containing the field names. This query can be called two ways:</p> |
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<p>1. You can supply the table name and call it from the <dfn>$this->db-></dfn> object:</p> |
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<code> |
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$fields = $this->db->list_fields('table_name');<br /><br /> |
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foreach ($fields as $field)<br /> |
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{<br /> |
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echo $field;<br /> |
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} |
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</code> |
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<p>2. You can gather the field names associated with any query you run by calling the function |
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from your query result object:</p> |
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<code> |
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$query = $this->db->query('SELECT * FROM some_table'); |
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<br /><br /> |
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foreach ($query->list_fields() as $field)<br /> |
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{<br /> |
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echo $field;<br /> |
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} |
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</code> |
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<h2>$this->db->field_exists()</h2> |
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<p>Sometimes it's helpful to know whether a particular field exists before performing an action. |
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Returns a boolean TRUE/FALSE. Usage example:</p> |
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<code> |
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if ($this->db->field_exists('field_name', 'table_name'))<br /> |
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{<br /> |
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// some code...<br /> |
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} |
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</code> |
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<p>Note: Replace <em>field_name</em> with the name of the column you are looking for, and replace |
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<em>table_name</em> with the name of the table you are looking for.</p> |
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<h2>$this->db->field_data()</h2> |
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<p>Returns an array of objects containing field information.</p> |
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<p>Sometimes it's helpful to gather the field names or other metadata, like the column type, max length, etc.</p> |
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<p class="important">Note: Not all databases provide meta-data.</p> |
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<p>Usage example:</p> |
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<code> |
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$fields = $this->db->field_data('table_name');<br /><br /> |
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foreach ($fields as $field)<br /> |
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{<br /> |
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echo $field->name;<br /> |
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echo $field->type;<br /> |
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echo $field->max_length;<br /> |
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echo $field->primary_key;<br /> |
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} |
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</code> |
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<p>If you have run a query already you can use the result object instead of supplying the table name:</p> |
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<code> |
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$query = $this->db->query("YOUR QUERY");<br /> |
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$fields = $query->field_data(); |
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</code> |
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<p>The following data is available from this function if supported by your database:</p> |
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<ul> |
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<li>name - column name</li> |
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<li>max_length - maximum length of the column</li> |
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<li>primary_key - 1 if the column is a primary key</li> |
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<li>type - the type of the column</li> |
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</ul> |
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<p> |
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Previous Topic: <a href="table_data.html"> Table Data</a> |
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