Question

我有一个主题库系统。我需要在主题预览页面中实现“相关主题”项目。

每个主题都有颜色和标签，所以在5个表之间我有：

主题
- id_theme
- 标题
颜色
- id_color
- title（red）
标签
- id_tag
- title（planetts）
theme_color
- id_theme
- id_color
theme_tag
- id_theme
- id_tag

问题是，我只需要收到5个结果，并且必须显示颜色和标签之间有更多匹配的结果。有了这个要求，我不知道从哪里开始。有什么想法吗？

Answer 1

如果您想要与给定主题共享最多项目的五个主题，您可以尝试以下内容：

DECLARE @target_id_theme INT;
SET @target_id_theme = 1; -- this is the id_theme you want to find similar themes for

SELECT t.id_theme, COUNT(*) as matching_things
FROM theme AS t
LEFT OUTER JOIN theme_color AS tc ON tc.id_theme = t.id_theme
LEFT OUTER JOIN theme_tag AS tt ON tt.id_theme = t.id_theme
WHERE tc.id_color IN (SELECT id_color FROM theme_color WHERE id_theme = @target_id_theme)
OR tt.id_tag IN (SELECT id_tag FROM theme_tag WHERE id_theme = @target_id_theme)
GROUP BY t.id_theme
ORDER BY COUNT(*) DESC
LIMIT 5

未经测试，买家要小心，但我希望你明白这一点。这会为每个颜色或标记创建一个行，该行匹配分配给@target_id_theme的颜色或标记，按计数递减排序，并为您提供前5个。

Answer 2

试试这个：

SELECT * FROM theme t
   FULL OUTER JOIN theme_color tc ON tc.id_theme = t.id_theme
   INNER JOIN color c ON c.id_color = tc.id_color
   FULL OUTER JOIN theme_tag tt ON tt.id_theme = t.id_theme
   INNER JOIN tag ta ON ta.id_tag = tt.id_tag
WHERE tag LIKE '%' + @KEYWORD + '%' OR color LIKE '%' + @KEYWORD + '%' OR title LIKE '%' + @KEYWORD + '%'

生成SQL查询以获取相关结果

2 个答案: