Question

实际上我正在研究一个项目，我正在研究Zend Framework 2如何处理复杂的查询（特别是关于如何连接n：m表以及如何使用GROUP_CONCAT和其他函数）。您是否知道执行此查询的最佳做法：

SELECT o. * , x.group_one, x.group_two
FROM table_one AS o
LEFT JOIN (
SELECT r.fk1, GROUP_CONCAT( t.field_one ) AS group_one, GROUP_CONCAT( t.field_two ) AS group_two
FROM table_three AS r
INNER JOIN table_two AS t ON r.fk2 = t.id
GROUP BY r.fk1
) AS x ON o.id = x.fk1
LIMIT 0 , 20;

使用此数据库架构：

--
-- Database: `table-test-1`
--

-- --------------------------------------------------------

--
-- Structure of table `table_one`
--

CREATE TABLE `table_one` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`field_1` varchar(255) NOT NULL,
`field_2` varchar(255) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=6 ;

--
-- Dump for table `table_one`
--

INSERT INTO `table_one` (`id`, `field_1`, `field_2`) VALUES
(1, 'baz', 'bat'),
(2, 'foo', 'bar'),
(3, 'foo2', 'bat2'),
(4, 'fuz', 'bar2'),
(5, 'poo', 'pee');

-- --------------------------------------------------------

--
-- Structure of table `table_three`
--

CREATE TABLE `table_three` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`fk1` bigint(20) NOT NULL,
`fk2` bigint(20) NOT NULL,
PRIMARY KEY (`id`),
KEY `fk1` (`fk1`,`fk2`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=10 ;

--
-- Dump for table `table_three`
--

INSERT INTO `table_three` (`id`, `fk1`, `fk2`) VALUES
(5, 1, 1),
(1, 1, 2),
(6, 1, 4),
(2, 2, 2),
(4, 3, 2),
(7, 3, 3),
(3, 4, 1),
(8, 5, 3),
(9, 5, 4);

-- --------------------------------------------------------

--
-- Structure of table `table_two`
--

CREATE TABLE `table_two` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`field_one` varchar(255) NOT NULL,
`field_two` varchar(255) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=5 ;

--
-- Dump for table `table_two`
--

INSERT INTO `table_two` (`id`, `field_one`, `field_two`) VALUES
(1, 'label_name_1', 'label_extended_name_1'),
(2, 'label_name_2', 'label_extended_name2'),
(3, 'label_name_3', 'label_extended_name_3'),
(4, 'label_name_4', 'label_extended_name4');

目前我解决了使用带有手工查询的Zend \ Db \ Sql \ Sql语句，但我想知道实际上是否有一种方法可以使用本机Select（）（可能没有）使用Doctrine或类似的东西）。

提前谢谢你：）

Answer 1

您必须导入use Zend\Db\Sql\Predicate\Expression;才能使用group_concat。

例如：

$sql = new Sql($this->adapter); 
$select = $sql->select();
$select->columns(array('*'));
$select->from('tblCGii');
$select->join("tblCGFieldValues", "tblCGii.id = tblCGFieldValues.Cgii_id",   array("field_values"=>new Expression("Group_Concat(tblCGFieldValues.field_values)")),"LEFT"); 
$select->group('tblCGii.id');

在Zend Framework 2上使用表达式执行多个连接

1 个答案: