如何将原始 SQL 查询转换为 Silverstripe SQL 查询抽象层

How to convert raw SQL query into Silverstripe SQLQuery abstraction layer

我有一个页面,我正在尝试从数据库中提取与该页面相关的文章。我有 SQL 查询可以提取我需要的内容,但我一直收到错误 "Unknown column 'Fashion' in 'where clause'"。我相信我需要将它从

$FilteredStories =  DB::query(' SELECT C.ID, C.URLSegment, C.Title, B.Title AS "Category"
                                FROM `articlepage_categories` AS A
                                JOIN articlecategory AS B ON A.ArticleCategoryID = B.ID
                                JOIN sitetree AS C ON A.ArticlePageID = C.ID
                                WHERE B.Title = "Fashion" LIMIT 5')
                    ->value();

进入SQL查询抽象层,但我不知道如何。有人可以告诉我如何创建具有多个连接的 SQL 查询抽象层吗?

备注

SilverStripe 的数据库默认使用ANSI sql_mode,其中字符串文字需要用单引号括起来。您需要将 "Fashion" 周围的双引号替换为单引号,如下所示:

$FilteredStories =  DB::query('SELECT C.ID, C.URLSegment, C.Title, B.Title AS "Category"
                            FROM `articlepage_categories` AS A
                            JOIN articlecategory AS B ON A.ArticleCategoryID = B.ID
                            JOIN sitetree AS C ON A.ArticlePageID = C.ID
                            WHERE B.Title = \'Fashion\' LIMIT 5')

此处转义,因为外引号是单引号。

您的查询将用 SQLSelect 表示,如下所示:

$filteredStories = SQLSelect::create();
$filteredStories->selectField('"sitetree"."ID", "sitetree"."URLSegment", "sitetree"."Title", "articlecategory"."Title" AS "Category"');
$filteredStories->setFrom('articlepage_categories');
$filteredStories->addLeftJoin('articlecategory', '"articlecategory"."ID" = "articlepage_categories"."ArticleCategoryID"');
$filteredStories->addLeftJoin('sitetree','"sitetree"."ID" = "articlepage_categories"."ArticlePageID"');
$filteredStories->addWhere('"articlecategory"."Title" = \'Fashion\'');
$filteredStories->setLimit(5);