check to see if db entry exists

[bryanptcs]

I need to check to see if the value for table_id already exists in the db.  If it does, a message needs to post and allow the user to choose a dif table id.

Here is what i have...i get the die message of could not execute query for $sql. Any help?
[code]
<?php
include("incl_db.php");

$connection = mysql_connect($host, $user, $password) or die ("Couldn't connect to the server.");
$db = mysql_select_db($database, $connection) or die ("Couldn't select database.");
$table_id = Trim(stripslashes($_POST['table_id']));
$company = Trim(stripslashes($_POST['company']));
$amt_tix = Trim(stripslashes($_POST['amt_tickets']));
$comments = Trim(stripslashes($_POST['comments']));
$sql = "SELECT table_id FROM Table";
$result = mysql_query($sql) or die("could not execute");
$num = mysql_numrows($result);
if ($num > 0)
{
echo "That table is already reserved";
header("Location: reservetable.php");
}
else
{

$sql2 = "INSERT INTO `Table` ( `table_id` ,`company` , `table_amt` , `comments` ) VALUES ('$table_id' , '$company', '$amt_tix', '$comments')";
$result2 = mysql_query($sql2) or die("Couldn't execute query.");

if ($result2 == "yes")
{
header("Location: index.php");
exit;
}
}
?>

[/code]

[trq]

Table is a reserved word in SQL. You will need to surround it in backticks or change the filed name.

[code=php:0]
$sql = "SELECT table_id FROM `Table`";
[/code]

[ShogunWarrior]

And table_id needs to be $table_id

[bryanptcs]

Ok, I have made the changes...but it does not seem like the program is running.  It just puts the message that the table already exists, even when it doesn't exist yet...

here is my updated code

[code]
<?php ob_start();
?>
<?php
include("incl_db.php");

$connection = mysql_connect($host, $user, $password) or die ("Couldn't connect to the server.");
$db = mysql_select_db($database, $connection) or die ("Couldn't select database.");
$table_id = Trim(stripslashes($_POST['table_id']));
$company = Trim(stripslashes($_POST['company']));
$amt_tix = Trim(stripslashes($_POST['amt_tickets']));
$comments = Trim(stripslashes($_POST['comments']));
$sql = "SELECT table_id FROM `Table`";
$result = mysql_query($sql) or die("could not execute");
$num = mysql_numrows($result);
if ($num > 0)
{
$new_message = "That table is already reserved";
//header("Location: reservetable.php");
include("reservetable.php");
exit;
}
else
{

$sql2 = "INSERT INTO `Table` ( `table_id` ,`company` , `table_amt` , `comments` ) VALUES ('$table_id' , '$company', '$amt_tix', '$comments')";
$result2 = mysql_query($sql2) or die("Couldn't execute query.");

if ($result2 == "yes")
{
header("Location: index.php");
exit;
}
}
?>
[/code]

[trq]

I think you missed ShowgunWarrior's post.

[code=php:0]
$sql = "SELECT $table_id FROM `Table`";
[/code]

[bryanptcs]

putting the $ in front of table_id errors the sql command and causes it not to execute...

[trq]

Your entire section of code should be within an if().

[code]
<?php
  if ($_POST['submit']) {
    // your code
  }
?>
[/code]

[bryanptcs]

i did that (updated code below) and it just produced a blank page.

[code]
<?php ob_start();
?>
<?php
if ($_POST['submit'])
{
include("incl_db.php");

$connection = mysql_connect($host, $user, $password) or die ("Couldn't connect to the server.");
$db = mysql_select_db($database, $connection) or die ("Couldn't select database.");
$table_id = Trim(stripslashes($_POST['table_id']));
$company = Trim(stripslashes($_POST['company']));
$amt_tix = Trim(stripslashes($_POST['amt_tickets']));
$comments = Trim(stripslashes($_POST['comments']));
$sql = "SELECT $table_id FROM `Table`";
$result = mysql_query($sql) or die("could not execute");
$num = mysql_numrows($result);
if ($num > 0)
{
$new_message = "That table is already reserved";
//header("Location: reservetable.php");
include("reservetable.php");
exit;
}
else
{

$sql2 = "INSERT INTO `Table` ( `table_id` ,`company` , `table_amt` , `comments` ) VALUES ('$table_id' , '$company', '$amt_tix', '$comments')";
$result2 = mysql_query($sql2) or die("Couldn't execute query.");

if ($result2 == "yes")
{
header("Location: index.php");
exit;
}
}
}
?>
[/code]

[trq]

Are you submitting a from to this script?

(By the way, your indentation is terrible).

[bryanptcs]

yes...

[code]
<form action="reservetable_action.php" method="POST">
<table border="0">


<tr>
  <td align="right"><b>Corporation</b></td>
  <td><input name="company" type="text" id="company" size="30" maxsize="50" /></td></tr>
<tr>
  <td width="120" align="right"><b>Amount of Tickets </b></td>
  <td><select name="amt_tickets" id="amt_tickets">
        <option value="2">2</option>
        <option value="4">4</option>
        <option value="6">6</option>
      </select></td>
</tr>
<tr>
  <td align="right">Table Required </td>
  <td><select name="table_id">
  <?php

  $tableName=getTableName();
$tableCode=getTableCode();
for ($n=1; $n<=54; $n++)
{
$table=$tableName[$n];
$tcode=$tableCode[$n];
echo "<option value='$tcode'";
if ($scode== "A1")
echo " selected";
echo ">$table\n";
}

?></select> <?php echo $new_message; ?>
 
  </td>
</tr>
<tr>
  <td align="right"><strong>Comments</strong></td>
  <td rowspan="4" valign="top"><label>
    <textarea name="comments" cols="30" rows="6" id="comments"></textarea>
  </label></td>
  </tr>
<tr>
  <td align="right">&nbsp;</td>
  </tr>
<tr>
  <td align="right">&nbsp;</td>
  </tr>
<tr>
  <td align="right">&nbsp;</td>
  </tr>
<tr><td align="center" colspan="2"><br /><input name="Submit" type="submit" id="Submit" value="Submit" />
</td></tr>
</table>
</form>
[/code]

Sorry about the indention...I am usually pretty good about it.

[trq]

Your using a capitol S in Submit.

[code=php:0]
if ($_POST['Submit'])
[/code]