MySQL - A query based on another query - php

Question

I write a lot of queries resembling the query example code below. I was wondering whether there was a more efficient code/script?
$query1 ="SELECT * FROM table1 WHERE date >= '$todaysdate' ";
$result1 = mysql_query($query1)
or die ("Error in query: $query1. " . mysql_error());
if (mysql_num_rows($result1) > 0) {
while($row1 = mysql_fetch_object($result1)) {
echo "$row1-date";
$query2 ="SELECT * FROM table2 WHERE table1ID >= '$row1-table1ID' ";
$result2 = mysql_query($query2)
or die ("Error in query: $query2. " . mysql_error());
if (mysql_num_rows($result2) > 0) {
while($row2 = mysql_fetch_object($result2)) {
echo "$row->datatable2";
}
}
}
}

Answer 1

Try using SQL JOINs, like the following example:
SELECT
*
FROM
table1
INNER JOIN
table2 ON (table2.table1ID = table1.ID)
WHERE
table1.date >= '2009-12-20';

Answer 2

I don't know about the structure of your tables, but I've modified your code so that it uses a join:
$query = 'SELECT table1.date, table2.datatable2 FROM table1, table2 WHERE table1.date >= \''.$todaysdate.'\' AND table2.table1ID >= table1.table1ID';
$result = mysql_query($query)
or exit('Error in query: '.$query.' '.mysql_error());
if (mysql_num_rows($result) > 0)
{
while($row = mysql_fetch_object($result))
{
echo $row->date;
echo $row->datatable2;
}
}
In this case you select multiple tables with FROM separated with commas, but you can also use INNER/OUTER/LEFT/RIGHT JOIN (see the link in the first answer).

Answer 3

You can use PDO.
Your queries should look like this..
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();
$result = $sth->fetchAll(PDO::FETCH_COLUMN);
// OR
$result = $sth->fetchAll(PDO::FETCH_OBJ);
var_dump($result);
PDO MANUAL: http://php.net/manual/en/book.pdo.php