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