SELECTING in two tables... - php

Question

I have two tables that I want to use for viewing my reports which I can get after inputting a date.
Here are my tables: for customers - customer_date, lastname, firstname
for services - room_number, date_in, date_out
Here is my code now : it seems that it can't get any rows from my table
<?php
$conn = mysql_connect("localhost","root","");
mysql_select_db('irm',$conn);
if(isset($_GET['Submit'])){
$customer_date = $_GET['customer_date'];
}
?>
<form method="get">
<table width="252" border="0">
<tr>
<td width="98">Choose Date:</td>
<td width="144"><label>
<input onclick="ds_sh(this);" name="customer_date" id="customer_date" readonly="readonly" style="cursor: text" />
</label></td>
</tr>
<tr>
<td align="right"><input type="submit" value="Submit" /></a></td>
<td></td>
</tr>
</table>
</form>
<form>
<?php
$tryshow = "SELECT * FROM customers,services WHERE customer_date = '$customer_date' ";
$result = #mysql_query($tryshow,$conn)
or die("cannot view error query");
if (mysql_num_rows($result) == 0) {
echo "No rows found, nothing to print...";
}
while($row=mysql_fetch_assoc($result)){
?>
<table width="700" border="0">
<tr>
<td width="100">Customer Date:</td>
<td width="100">Last Name</td>
<td width="100">First Name</td>
<td width="100">Room Number</td>
<td width="100">Date In</td>
<td width="100">Date Out</td>
</tr>
<tr>
<td><?php echo $row["customer_date"]; ?></td>
<td><?php echo $row['lastname']; ?></td>
<td><?php echo $row['firstname']; ?></td>
<td><?php echo $row['room_number']; ?></td>
<td><?php echo $row['date_in']; ?></td>
<td><?php echo $row['date_out']; ?></td>
</tr>
</table>
<?php }?>
</form>
With this I can get a report of any customer who checks in on that date.
I need some advice. Hope you can answer me soon.

Answer 1

You don't appear to have any fields in common between the two tables. How do you store fact that customer A was in room B on date C? To do an SQL join, the tables being joined have to have at least one field in common.
As well, instead of just saying die("cannot view error query"), which is utterly useless for debugging purposes, try doing die(mysql_error(), which will give you the exact reason the query failed.
As well, if the query DOES work, then you're outputting an entire HTML table for each row found. You should have the table headers and footers data OUTSIDE of the fetch loop.

Answer 2

You need to relate the two tables with a JOIN. Based on the information given, customers.customer_date to services.date_in seems to be the most likely candidate. This assumes that the date columns hold only a date and not a date/time.
Also notice that I'm not using select * in my query and neither should you. ;-)
SELECT c.customer_date, c.lastname, c.firstname,
s.room_number, s.date_in, s.date_out
FROM customers c
INNER JOIN services s
ON c.customer_date = s.date_in
WHERE c.customer_date = '$customer_date'

Answer 3

When your making query to database make sure your date format is yyyy-mm-dd
Mysql understand date in this format only so that you have to compare the date format in this format only.
your $customer_date should be in the yyyy-mm-dd format

Answer 4

As an aside, I'd change customer_date to something more meaningful such as "date_in." (It's a good thing when the names are predictable!) You don't need to specify that it's the customer since it's in the customer table already.