我有两个桌子。第一个具有主要产品数据，另一个具有这些产品的辅助描述，通过第二个表上的products_id外键链接。
我已经创建了SQL，一切看起来都不错。但是，当我用相同的结果SQL代码转换为CakePHP 3的ORM时，它出现了一个大问题：每个页面都显示了第二个数据表的辅助描述。
在首页分页索引中，拥有主要产品的索引按预期工作。首先，显示主要产品，然后，描述显示辅助表数据中的辅助描述。但是，当我单击以查看下一页时，当我期望从此表数据中获得任何收益时，这些次要产品就在那里。
仅当该页面上有主要产品时，我才需要显示这些辅助描述，而该产品不存在时，则不会显示该表中的任何记录。就像在SQL脚本结果中一样。
在此SQL脚本上，您可以看到我需要的内容：
(SELECT
Products.id,
(null) AS product_titles_id,
(Products.title) AS title_,
Products.product_groups_id,
Products.product_types_id,
Products.code,
Products.title,
Products.ean,
Products.ncm,
Products.obs,
Products.minimum,
Products.maximum,
ProductTypes.id,
ProductTypes.code,
ProductTypes.title,
ProductTypes.calc_cost,
ProductGroups.id,
ProductGroups.code,
ProductGroups.title
FROM `products` Products
LEFT JOIN `product_groups` ProductGroups ON Products.product_groups_id = ProductGroups.id
LEFT JOIN `product_types` ProductTypes ON Products.product_types_id = ProductTypes.id)
UNION
(SELECT
Products.id,
ProductTitles.id AS product_titles_id,
(ProductTitles.title) AS title_,
Products.product_groups_id,
Products.product_types_id,
-- ProductTitles.products_id,
ProductTitles.code,
ProductTitles.title,
Products.ean,
Products.ncm,
ProductTitles.obs,
Products.minimum,
Products.maximum,
ProductTypes.id,
ProductTypes.code,
ProductTypes.title,
ProductTypes.calc_cost,
ProductGroups.id,
ProductGroups.code,
ProductGroups.title
FROM `product_titles` ProductTitles
LEFT JOIN `products` Products ON products.id = ProductTitles.products_id
LEFT JOIN `product_groups` ProductGroups ON Products.product_groups_id = ProductGroups.id
LEFT JOIN `product_types` ProductTypes ON Products.product_types_id = ProductTypes.id)
ORDER BY title_
这是该SQL脚本的结果：
id product_titles_id title_
0080 NULL SUPORTE DE PRESSAO
7545 NULL BA RET.
3177 NULL CORT RDX
3177 17 EMEN RDX (secondary description)
3177 18 PART RDX (secondary description)
6623 NULL LATAO CALCO CALIB.
8079 NULL TRANSM DE PRESSAO
4242 NULL GY 6/6 P.U CORAL
这是我在CakePHP ORM脚本上所做的：
//Main table of products
$qry_products = $this->Products->findByParametersId('85')
->select(['Products.id', 'product_titles_id' => 'null',
'title_' => 'Products.title',
'Products.product_groups_id',
'Products.product_types_id',
'Products.code', 'Products.title',
'Products.ean', 'Products.ncm',
'Products.obs', 'Products.minimum',
'Products.maximum', 'ProductTypes.id',
'ProductTypes.code', 'ProductTypes.title',
'ProductTypes.calc_cost', 'ProductGroups.id',
'ProductGroups.code', 'ProductGroups.title',
'ProductTitles' => '0'
])
->where($where)
->join([
'ProductGroups' => ['table' => 'product_groups',
'type' => 'LEFT',
'conditions' => 'Products.product_groups_id = ProductGroups.id'
],
'ProductTypes' => ['table' => 'product_types',
'type' => 'LEFT',
'conditions' => 'Products.product_types_id = ProductTypes.id'
]
])
->limit(20);
//Secondary table of products' descriptions:
$qry_productTitles = $this->ProductTitles->findByParametersId('85')
->select(['Products.id',
'product_titles_id' => 'ProductTitles.id',
'title_' => 'ProductTitles.title',
'product_groups_id' => 'Products.product_groups_id',
'product_types_id' => 'Products.product_types_id',
'ProductTitles.code', 'ProductTitles.title',
'ean' => 'Products.ean',
'ncm' => 'Products.ncm',
'obs' => 'Products.obs',
'minimum' => 'Products.minimum',
'maximum' => 'Products.maximum',
'ProductTypes.id', 'ProductTypes.code',
'ProductTypes.title',
'ProductTypes.calc_cost',
'ProductGroups.id', 'ProductGroups.code',
'ProductGroups.title',
'ProductTitles' => '1'
])
->join([
'Products' => ['table' => 'products',
'type' => 'LEFT',
'conditions' => 'ProductTitles.products_id = Products.id'
],
'ProductGroups' => ['table' => 'product_groups',
'type' => 'LEFT',
'conditions' => 'Products.product_groups_id = ProductGroups.id'
],
'ProductTypes' => ['table' => 'product_types',
'type' => 'LEFT',
'conditions' => 'Products.product_types_id = ProductTypes.id'
]
]);
//Union these two tables and put some where conditions and ordanation:
$products = $qry_products->union($qry_productTitles)
->where($where)
->epilog('ORDER BY title_');
//->order(['title_ ASC']);
这是从CakePHP ORM生成的SQL结果：
'sql' => '
(SELECT Products.id AS `Products__id`,
null AS `product_titles_id`, Products.title AS `title_`,
Products.product_groups_id AS `Products__product_groups_id`,
Products.product_types_id AS `Products__product_types_id`,
Products.code AS `Products__code`,
Products.title AS `Products__title`,
Products.ean AS `Products__ean`,
Products.ncm AS `Products__ncm`,
Products.obs AS `Products__obs`,
Products.minimum AS `Products__minimum`,
Products.maximum AS `Products__maximum`,
ProductTypes.id AS `ProductTypes__id`,
ProductTypes.code AS `ProductTypes__code`,
ProductTypes.title AS `ProductTypes__title`,
ProductTypes.calc_cost AS `ProductTypes__calc_cost`,
ProductGroups.id AS `ProductGroups__id`,
ProductGroups.code AS `ProductGroups__code`,
ProductGroups.title AS `ProductGroups__title`,
0 AS `ProductTitles`
FROM products Products
LEFT JOIN product_groups ProductGroups ON Products.product_groups_id = ProductGroups.id
LEFT JOIN product_types ProductTypes ON Products.product_types_id = ProductTypes.id
ORDER BY title_ LIMIT 20)
UNION
(SELECT Products.id AS `Products__id`,
ProductTitles.id AS `product_titles_id`,
ProductTitles.title AS `title_`,
Products.product_groups_id AS `product_groups_id`,
Products.product_types_id AS `product_types_id`,
ProductTitles.code AS `ProductTitles__code`,
ProductTitles.title AS `ProductTitles__title`,
Products.ean AS `ean`, Products.ncm AS `ncm`,
Products.obs AS `obs`, Products.minimum AS `minimum`,
Products.maximum AS `maximum`,
ProductTypes.id AS `ProductTypes__id`,
ProductTypes.code AS `ProductTypes__code`,
ProductTypes.title AS `ProductTypes__title`,
ProductTypes.calc_cost AS `ProductTypes__calc_cost`,
ProductGroups.id AS `ProductGroups__id`,
ProductGroups.code AS `ProductGroups__code`,
ProductGroups.title AS `ProductGroups__title`,
1 AS `ProductTitles`
FROM product_titles ProductTitles
LEFT JOIN products Products ON ProductTitles.products_id = Products.id
LEFT JOIN product_groups ProductGroups ON Products.product_groups_id = ProductGroups.id
LEFT JOIN product_types ProductTypes ON Products.product_types_id = ProductTypes.id)
ORDER BY title_',
答案 0 :(得分：0)
使用以下代码解决了问题：
$products_union = "((SELECT
Products.id AS `id`,
Products.product_groups_id,
Products.product_types_id,
Products.code AS `code`,
Products.title AS `title`,
Products.ean AS `ean`,
Products.ncm AS `ncm`,
Products.obs AS `obs`,
Products.minimum AS `minimum`,
Products.maximum AS `maximum`,
ProductTypes.id AS `ProductTypes__id`,
ProductTypes.code AS `ProductTypes__code`,
ProductTypes.title AS `ProductTypes__title`,
ProductTypes.calc_cost AS `ProductTypes__calc_cost`,
ProductGroups.id AS `ProductGroups__id`,
ProductGroups.code AS `ProductGroups__code`,
ProductGroups.title AS `ProductGroups__title`
FROM `products` Products
LEFT JOIN `product_groups` ProductGroups
ON Products.product_groups_id = ProductGroups.id
LEFT JOIN `product_types` ProductTypes
ON Products.product_types_id = ProductTypes.id)
UNION ALL
(SELECT
Products.id AS `id`,
Products.product_groups_id,
Products.product_types_id,
ProductTitles.code AS `code`,
ProductTitles.title AS `title`,
Products.ean AS `ean`,
Products.ncm AS `ncm`,
ProductTitles.obs AS `obs`,
Products.minimum AS `minimum`,
Products.maximum AS `maximum`,
ProductTypes.id AS `ProductTypes__id`,
ProductTypes.code AS `ProductTypes__code`,
ProductTypes.title AS `ProductTypes__title`,
ProductTypes.calc_cost AS `ProductTypes__calc_cost`,
ProductGroups.id AS `ProductGroups__id`,
ProductGroups.code AS `ProductGroups__code`,
ProductGroups.title AS `ProductGroups__title`
FROM `product_titles` ProductTitles
LEFT JOIN `products` Products
ON Products.id = ProductTitles.products_id
LEFT JOIN `product_groups` ProductGroups
ON Products.product_groups_id = ProductGroups.id
LEFT JOIN `product_types` ProductTypes
ON Products.product_types_id = ProductTypes.id
))";
$products = $this->Products->find('all')
->from([$this->Products->alias() => $products_union])
->contain(['ProductTypes', 'ProductGroups'])
->where($where)
->order(['Products.title']);
现在，“ LIMIT”和“ OFFSET”在正确的位置。我仍然使用3.4 CakePHP版本。