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63 <h2>$this-
>db-
>list_fields()
</h2>
64 <p>Returns an array containing the field names. This query can be called two ways:
</p>
67 <p>1. You can supply the table name and call it from the
<dfn>$this-
>db-
></dfn> object:
</p>
70 $fields = $this-
>db-
>list_fields('table_name');
<br /><br />
72 foreach ($fields as $field)
<br />
74 echo $field;
<br />
78 <p>2. You can gather the field names associated with any query you run by calling the function
79 from your query result object:
</p>
82 $query = $this-
>db-
>query('SELECT * FROM some_table');
85 foreach ($query-
>list_fields() as $field)
<br />
87 echo $field;
<br />
92 <h2>$this-
>db-
>field_exists()
</h2>
94 <p>Sometimes it's helpful to know whether a particular field exists before performing an action.
95 Returns a boolean TRUE/FALSE. Usage example:
</p>
98 if ($this-
>db-
>field_exists('field_name', 'table_name'))
<br />
100 // some code...
<br />
104 <p>Note: Replace
<em>field_name
</em> with the name of the column you are looking for, and replace
105 <em>table_name
</em> with the name of the table you are looking for.
</p>
108 <h2>$this-
>db-
>field_data()
</h2>
109 <p>Returns an array of objects containing field information.
</p>
110 <p>Sometimes it's helpful to gather the field names or other metadata, like the column type, max length, etc.
</p>
113 <p class=
"important">Note: Not all databases provide meta-data.
</p>
115 <p>Usage example:
</p>
118 $fields = $this-
>db-
>field_data('table_name');
<br /><br />
120 foreach ($fields as $field)
<br />
122 echo $field-
>name;
<br />
123 echo $field-
>type;
<br />
124 echo $field-
>max_length;
<br />
125 echo $field-
>primary_key;
<br />
129 <p>If you have run a query already you can use the result object instead of supplying the table name:
</p>
132 $query = $this-
>db-
>query("YOUR QUERY");
<br />
133 $fields = $query-
>field_data();
137 <p>The following data is available from this function if supported by your database:
</p>
140 <li>name - column name
</li>
141 <li>max_length - maximum length of the column
</li>
142 <li>primary_key -
1 if the column is a primary key
</li>
143 <li>type - the type of the column
</li>
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</a>
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