Question

I am trying to update a row in a mysql database. To do this, I would use a simple query like this:

    "UPDATE  `contactinfo` SET  `Company` =  'Google', WHERE `id` =  '1';"

The problem is that the database is dynamic and users can add columns at any time. So I do not know the names of the columns. To find the names and create a form to post to the page that will actually do the mysql work uses this code:

    <?php
            $result = mysql_query("select * from contactinfo WHERE `id` = '".$rid."';");

            if (!$result) {
                die('Query failed: ' . mysql_error());
            }
            $i = 0;
            while ($i < mysql_num_fields($result)) {
                $meta = mysql_fetch_field($result, $i);
                if (!$meta) {
                    echo "ERROR";
                }
                $name = $meta->name;

                $r = mysql_fetch_array(mysql_query("select * from contactinfo WHERE `id` = '".$rid."';"));
                $content = $r[$name];

                if($name != 'id') {
                    echo "<tr><td align='center'><div align='left'>Edit ".$name."</div></td></tr>";
                    echo "<tr><td align='center'><input type='text' value='" . $content . "' /></td></tr>";
                }
                $i++;
            }
            mysql_free_result($result);
        ?>

This creates a nice little table with input boxes that allow the user to edit the content of the row that has been selected. The row id number($rid) is used to identify which row needs to be changed.

My question is, how can I get the new content for the row from the posted form and create a query to update it? I can’t seem to figure out how to dynamically get the names of the form as well as the new content to the write the query.

If any clarification is needed just let me know and all help is appreciated.

Thanks.

Answer 1

The easiest way is to name the fields in the form exactly how the name of the fields in the database are.
Lets say you have this form

<form action="">
   <input name="field[firstname]">
   <input name="field[lastname]">
   <input name="field[address]">
</form>

You should probably be able to create the form based on the fields names too, you are probably already doing this.
In the file that processes the response you can do something like this:

foreach($_POST['field'] as $field_name => $field_value) {
   $sql_str[] = "{$field_name} = '{$field_value}'";
}

This just goes through the ‘field’ array that comes from post and puts the proper update text into another array.
Then just do a

mysql_query("UPDATE contactinfo SET ".implode(',', $sql_str)." WHERE `id` = '".$rid."';")

To put it into the database.