Query 2 tables with one field linked to 2 different values - mysql

Question

I'm trying to make a SQL query and I have some problems with it.
CREATE table entries (
id_entry INT PRIMARY KEY,
);
CREATE table entry_date (
entry_date_id INT PRIMARY KEY,
entry_id INT,
entry_price INT,
entry_date TEXT,
);
for each entry, there is several dates.
I'd like to select the entries.entry_id where that entry have, for example, the dates '23/03/2013' and '24/03/2013' linked to it.
The two dates are stored into an array:
$data = array('ci' => '23/03/2013', 'co' => '24/03/2013');
I store the dates in text for practical purpose in my treatment.
I use Zend_Db so my query is constructed like that:
$select = $table->select ()->from ( 'entries' )->setIntegrityCheck ( false );
if ($data ['ci'] != NULL) {
$select->join ( array (
'entry_dates' => 'entry_dates'
), 'entries.id_entry = entry_dates.entry_id' );
$select->where ( 'entry_dates.entry_date = ?', $data ['ci'] );
}
if ($data ['co']) {
if ($data['ci'] == NULL) {
$select->join ( array (
'entry_dates' => 'entry_dates'
), 'entries.id_entry = entry_dates.entry_id' );}
$select->where ( 'entry_dates.entry_date = ?', $data ['co'] );
}
which gives :
SELECT `entries`.*, `entry_date`.*
FROM `entries`
INNER JOIN `entry_dates`
ON entries.id_entry = entry_dates.entry_id
WHERE (entry_dates.entry_date = '23/03/2013')
AND (entry_dates.entry_date = '24/03/2013')
And, well ... It doesn't work.
When I fetch my $select, I get nothing.
I guess I miss something in my request when I do the WHERE ... AND , what should I do to get the correct output ? The real request being really long, I'd like to avoid another long subselect if possible.

Answer 1

It can be done in two way, either with a self-join on the entry_date table:
SELECT `entries`.entry_id
FROM `entries`
INNER JOIN `entry_dates` AS ed1
ON entries.id_entry = ed1.entry_id
INNER JOIN `entry_dates` AS ed2
ON entries.id_entry = ed2.entry_id
WHERE ed1.entry_date = '23/03/2013'
AND ed2.entry_date = '24/03/2013'
Or with an aggregate
SELECT `entries`.entry_id
FROM `entries`
INNER JOIN `entry_dates` AS ed
WHERE ed.entry_date = '23/03/2013'
OR ed2.entry_date = '24/03/2013'
GROUP BY `entries`.entry_id
HAVING COUNT(DISTINCT ed.entry_date)=2