insert value from drop down box to the database - php

Question

I am missing something from my code and I don't know how to make it work. I may have programed it wrong and that could be giving me my troubles. I am new at php and things have been going slowly. please understand that the code my not be organized as it should be. After creating about 12 pages of code I found out that I should be using mysqli or pod. Once I get everything working that will be the next project. Enough said here is my issue. I was able to populate my drop down box and there shows no errors on the page. Also all the data does get inserted into the database except for the section made on the drop down box. Here is my code. I will leave out all of the input fields except the drop down.
<?php
{$userid = $getuser[0]['username'];}
// this is processed when the form is submitted
// back on to this page (POST METHOD)
if ($_SERVER['REQUEST_METHOD'] == "POST")
{
# escape data and set variables
$tank = addslashes($_POST["tank"]);
$date = addslashes($_POST["date"]);
$temperature = addslashes($_POST["temperature"]);
$ph = addslashes($_POST["ph"]);
$ammonia = addslashes($_POST["ammonia"]);
$nitrite = addslashes($_POST["nitrite"]);
$nitrate = addslashes($_POST["nitrate"]);
$phosphate = addslashes($_POST["phosphate"]);
$gh = addslashes($_POST["gh"]);
$kh = addslashes($_POST["kh"]);
$iron = addslashes($_POST["iron"]);
$potassium = addslashes($_POST["potassium"]);
$notes = addslashes($_POST["notes"]);
// build query
// # setup SQL statement
$sql = " INSERT INTO water_parameters ";
$sql .= " (id, userid, tank, date, temperature, ph, ammonia, nitrite, nitrate, phosphate, gh, kh, iron, potassium, notes) VALUES ";
$sql .= " ('', '$userid', '$tank', '$date', '$temperature', '$ph', '$ammonia', '$nitrite', '$nitrate', '$phosphate', '$gh', '$kh', '$iron', '$potassium', '$notes') ";
// #execute SQL statement
$result = mysql_query($sql);
// # check for error
if (mysql_error()) { print "Database ERROR: " . mysql_error(); }
print "<h3><font color=red>New Water Parameters Were Added</font></h3>";
}
?>'
Here is the drop down
<tr><td><div align="left"><b>Tank Name: </b> </div></td><td><div align="left">
<?php
echo "<select>";
$result = mysql_query("SELECT tank FROM tank WHERE userid = '$userid'");
while($row = mysql_fetch_array($result))
{
echo "". $row["tank"] . "";
}
echo "";
?>
</div></td></tr>

Answer 1

You missed some code in while loop.
while($row = mysql_fetch_array($result))
{
echo "<option>".$row['tank']."</option>";
}
echo "</select>";

Answer 2

are you able to build drop down menu or box. if not try this query
$sql="SELECT `tank` FROM `tank` WHERE user_name='$user'";
$result=mysqli_query($dbc,$sql)
//here $dbc is a variable which you use to connect with the database.
Otherwise leave that only read from here why you need to change your code. in the while loop
one one more thing you have to give your select attribute a name, because it will return the value through name so give a name to your select attributes as you are using tank while building your drop down menu so i will give a same name tank. Than you dont have to change anything.
and you have to give value to your option as well, thanks
echo "<select name='age'>";
while($row = mysql_fetch_array($result))
{
echo "<option value='" . $row['tank'] . "' >" . $row['tank'] . "</option>";
}
echo "</select>";