how to prevent duplicate data if data get from DB?

Question

i have a form that consist of two textfield and one combobox. i want prevent the duplicate entry data from client side. i get combobox data from DB, like:

<select id="line" name="faline" >
<?php
   $sql="SELECT `Line_Name` FROM `prod_sch` WHERE `Line_Name` LIKE 'FA %' GROUP BY `Line_Name` ORDER BY `Line_Name`";
   if ($sql) {
               $res=mysql_query($sql) or _doError(_ERROR30 . ' (<small>' . htmlspecialchars($sql) . '</small>): ' . mysql_error() );
              }
   while ($dat = mysql_fetch_array($res, MYSQL_NUM)) {
           echo "\t\t\t\t\t\t\t\t<option value='".$dat[0]."'>".$dat[0]."</option>\n";
         }
?>
</select>

how to combine or modify this code:

<script language="javascript" type="text/javascript">
    $(function() {
        $("#Button1").click(function(e) {
            var itemExists = false;
            var txt = $("#Text1").val();
            e.preventDefault();
            $("#Select1 option").each(function() {
                if ($(this).text() == $.trim(txt)) {
                    itemExists = true;
                    alert('Item already exists');
                }
            });

          if (!itemExists) {
          $("#Select1").append("<option value=\"1\">" + txt + "</option>");
          $("#Text1").val('');
          }
        });
    });           
</script>

Where did you adopt this style of indention? I haven't seen it before, and it looks a bit ... messy. — strager
– strager, Commented Aug 11, 2010 at 3:20

Jacob Relkin · Accepted Answer · 2010-08-11 03:20:36Z

2

I believe that using SELECT DISTINCT will do the trick.

answered Aug 11, 2010 at 3:20

Jacob Relkin

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strager · Accepted Answer · 2010-08-11 03:20:25Z

1

First, build an array with the Line_Names:

<select id="line" name="faline" >
<?php
   $sql="SELECT `Line_Name` FROM `prod_sch` WHERE `Line_Name` LIKE 'FA %' GROUP BY `Line_Name` ORDER BY `Line_Name`";
   if ($sql) {
               $res=mysql_query($sql) or _doError(_ERROR30 . ' (<small>' . htmlspecialchars($sql) . '</small>): ' . mysql_error() );
              }

   $lineNames = array();
   while ($dat = mysql_fetch_array($res, MYSQL_NUM)) {
           $lineNames[] = $dat[0];
         }

Then call array_unique:

   $lineNames = array_unique($lineNames);

And finally iterate once again:

   foreach ($lineNames as $lineName) {
           echo "\t\t\t\t\t\t\t\t<option value='".$lineName."'>".$lineName."</option>\n";
           }
?>
</select>

answered Aug 11, 2010 at 3:20

strager

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3 Comments

Jacob Relkin Over a year ago

I believe that my answer is more efficient, not to mention that it's less code :)

strager Over a year ago

This looked like a PHP question to me, not a SQL one.

klox Over a year ago

@all:please check again my question..i have changed it.

hookenz · Accepted Answer · 2010-08-11 03:24:06Z

0

Can't you just use SQL to do this for you? i.e. by using the distinct keyword

$sql="SELECT distinct `Line_Name` FROM `prod_sch` WHERE `Line_Name` LIKE 'FA %' GROUP BY `Line_Name` ORDER BY `Line_Name`";

Sorry I had unique there before I meant distinct.

answered Aug 11, 2010 at 3:24

hookenz

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2 Comments

strager Over a year ago

I thought UNIQUE was an indexing constraint. Can it really be used like this?

klox Over a year ago

i have change my question..for getting combobox data there is no problem.

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