Reading sql table with a single general dynamic function - php

Question

I am trying to create a function that reads more easy any sql table no matter what number of columns.
class control_panel {
public function read_table($table_name, array $col_names) {
global $db;
$i = 0;
$result = $db->query("SELECT * FROM $table_name");
while($data = $result->fetch_object()) {
$i++;
foreach($col_names as $col_name) {
$cols[] = $data->$col_name;
}
}
var_dump($cols);
$nr_cols = count($cols);
/*for($j = 0; $j <= $nr_cols $j++) {
$cols[$j] =
}*/
}
}
$cp = new control_panel;
$col_names = array('ID', 'NewsTitle', 'NewsDescrption');
$cp->read_table('newss', $col_names);
Table structure:
ID NewsTitle NewsDescrption
1 title description
10 sda sd
Current output of the var_dump is:
array (size=6)
0 => string '1' (length=1)
1 => string 'title' (length=5)
2 => string 'descroierererer' (length=15)
3 => string '10' (length=2)
4 => string 'sda' (length=3)
5 => string 'sd' (length=2)
Expected output is to echo the table rows when I do $cp->read_table('newss', $col_names); in this way:
<tr>
<td>1</td>
<td>title</td>
<td>description</td>
</tr>
<tr>
<td>10</td>
<td>sda</td>
<td>sd</td>
</tr>
UPDATE change firts block of code to this as per David Jones answer.
public function read_table($table_name, array $col_names) {
global $db;
$results = array();
$result = $db->query("SELECT ".implode(',', $col_names)." FROM $table_name");
while($data = $result->fetch_object()) {
$results[] = $data;
}
foreach($results as $result) {
// how do I ouput dinamically here
//echo $result->$col_name...... this would lied to another array
}
}

Answer 1

Try this. You should only select the columns that you pass in rather than the whole table to limit un needed processing.
class control_panel {
public function read_table($table_name, array $col_names) {
global $db;
$results = array();
$result = $db->query("SELECT ".implode(',', $col_names)." FROM $table_name");
while($data = $result->fetch_object()) {
$results[] = $data;
}
return $results;
}
}
$cp = new control_panel;
$col_names = array('ID', 'NewsTitle', 'NewsDescrption');
$results = $cp->read_table('newss', $col_names);
$table = '';
foreach ($results as $item) {
$table .= '<tr>
<td>'.$item->ID.'</td>
<td>'.$item->NewsTitle.'</td>
<td>'.$item->NesDescription.'</td>
</tr>';
}
var_dump($table);
This should return an array of objects. Then you can access each column in a loop to show your table.
UPDATE:
You shouldn't loop through and generate your table inside the method as it is suppose to be generic and reusable. Instead return the results and loop in the controller or main PHP file.