如何将mysql记录显示为预先选中的复选框？

Question

I have a table column called post_tags within a table called posts where assigned tags are stored separated by the @ symbol. I also have a table called tags where all tag names are stored. I would like to design my database in a more normalized way but for the purpose I am trying to achieve this is the easiest option.

Anyway, I want to display on the screen all the entries from the tags table as checkboxes, so I do:

    $query = mysql_query("SELECT * FROM tags ORDER BY name");

    while ($row = mysql_fetch_assoc($query)) {

        $tag = $row['name'];

        echo "<input type='checkbox' name='tags[]' value='$tag' />
";

    }

Next I want to have the tags that are assigned to a particular post be preselected. For example, if I have a post with the following in it's post_tags column:

party@beaches@dolphins@

I want the "party", "beaches" and "dolphin" checkboxes to be checked by default (while the checkboxes for the other options are unchecked). How can this be done?

Answer 1

The first thing to do is see if there is any existing data. So run that query and put the result of that table cell into lets say $checkedstring if not then put your default string in.

<?php
$checkedstring = "party@beaches@dolphins@";
//Pull from DB if exsists and set $checkedstring to that value
///
$checkeditems =  explode ( "@" , $checkedstring);
$checked = array();
foreach($checkeditems as $item)
{
  $checked[$item]=true;
}    

$query = mysql_query("SELECT * FROM tags ORDER BY name");

while ($row = mysql_fetch_assoc($query)) 
{
    $tag = $row['name'];
    $checkedstatus = '';
    if($checked[$tag])
    {
      $checkedstatus = "checked='checked'";
    }
    echo "<input type='checkbox' name='tags[]' value='$tag' $checkedstatus />
";
}


?>