WHERE IN sql query using Zend_Db

问题

Zend Framework beginner here. I'm trying to fetch all the Xbox titles of a video game database. One table contains games. Another table contains game types (ie. Xbox, Xbox Live Arcade, ...). I normally use the following query to get the Xbox titles.

How can I execute the same query using Zend_Db?

Thanks,

SELECT titleGame
FROM Game 
WHERE idGameType IN (
    SELECT idGameType 
    FROM GameType 
    WHERE nameGameType = 'Xbox')

回答1:

That could be rewritten in Zend Framework a few ways. Here is the way I typically write selects like that using Zend_Db_Table_Select.

<?php

// For brevity, $dbTable = a Zend_Db_Table object

// first construct the subquery/join for the IN clause
// SELECT idGameType FROM GameType HERE nameGameType = 'Xbox'
$subselect = $dbTable->select()
                     ->from('GameType', array('idGameType'))
                     ->where('nameGameType = ?', 'Xbox'); // quotes Xbox appropriately, prevents SQL injection and errors

// construct the primary select
// SELECT titleGame FROM Game WHERE idGameType IN (subquery)
$select = $dbTable->select()
                  ->setIntegrityCheck(false) // allows us to select from another table
                  ->from($dbTable, array('titleGame'))
                  ->where('idGameType IN (?)', $subselect);

$results = $select->query()->fetchAll(); // will throw an exception if the query fails
if(0 === count($results)) {
    echo "No Results";
}else{
    foreach($results as $result){
        echo $result['titleGame'] . '<br />';
    }
}

You can also write the SQL as a string, but when possible, the object-oriented approach is ideal because it makes the queries more portable, and most importantly makes it very easy to secure your queries.

Example:

$db = Zend_Db_Table::getDefaultAdapter();  // get the default Db connection
$db->select("select * from table where id = 3"); // doable, but not recommended

You can also create a prepared statement through Zend_Db_Statement to PHP's PDO extension.

$sql = 'SELECT * FROM bugs WHERE reported_by = ? AND bug_status = ?';
$stmt = new Zend_Db_Statement_Mysqli($db, $sql);
$stmt->execute(array('goofy', 'FIXED'));

The first approach, the object oriented fluent interface is what you will see the most, and the method I would recommend starting out with and using.

Read through the Zend_Db Manual Pages, and in particular, Zend_Db_Table_Select, Zend_Db_Table, and Zend_Db_Adapter for more information. Even a quick read through over the ZF Quickstart paying specific attention to the Db portion is helpful. It will show how to set up table classes to be a gateway between your application and the database.

回答2:

SELECT titleGame FROM Game
LEFT JOIN GameType ON GameType.idGameType = Game.idGameType
WHERE GameType.nameGameType = 'Xbox'

Why not use a join instead? From my experience a subselect inside of IN is very slow in MySQL.

$select = $db->select();
$select->from('Game', array('titleGame'));
$select->joinLeft('GameType', 'GameType.idGameType = Game.idGameType', array());
$select->where("GameType.nameGameType = 'Xbox'");

来源：https://stackoverflow.com/questions/9492586/where-in-sql-query-using-zend-db

标签

zend-framework

zend-db