具有逻辑操作的高性能 SQL 标签搜索查询

Question

How can I implement a boolean tag search in SQL?
这个问题是我能找到的最接近的问题，但有一些。

我知道的唯一真正的解决方案是通过后端代码生成这样的查询并将其放入SQL，但我想它很慢，我也想知道是否有其他方法可以做到这一点（例如有一个主查询而不是多个）。

还有可能使用 IN 或类似的解决方案：

我无法使用典型的 GROUP BY HAVING COUNT 解决方案，因为它无法在具有标签列表的上下文中运行，正如该用户指出的那样：Implementing a tag search with operands

我应该指出大多数现有解决方案都不起作用，因为我正在寻找能够进行更复杂查询（例如括号分组和嵌套操作数）的东西。

架构是“Toxi”http://howto.philippkeller.com/2005/04/24/Tags-Database-schemas/

SELECT id AS post_id
FROM posts
WHERE EXISTS (SELECT name FROM tags WHERE post IS post_id AND name IS 'random')
AND NOT (
    EXISTS (SELECT name FROM tags WHERE post IS post_id AND name IS 'query') AND
    EXISTS (SELECT name FROM tags WHERE post IS post_id AND name IS '1')
)
AND EXISTS (SELECT name FROM tags WHERE post IS post_id AND name IS '2') 
AND EXISTS (SELECT name FROM tags WHERE post IS post_id AND name IS '3')
AND EXISTS (SELECT name FROM tags WHERE post IS post_id AND name IS 'racecar')

Answer 1

架构准备

CREATE TABLE posts (
    ID INT PRIMARY KEY IDENTITY(1,1),
    subj nvarchar(50)
)
GO

CREATE TABLE tags (
    post INT,
    name nvarchar(50)
)
GO

数据准备

INSERT INTO posts (subj) VALUES ('post1')
INSERT INTO posts (subj) VALUES ('post2')
INSERT INTO posts (subj) VALUES ('post3')

INSERT INTO tags VALUES (1, 'food')
INSERT INTO tags VALUES (1, 'spicy')

INSERT INTO tags VALUES (2, 'spicy')
INSERT INTO tags VALUES (2, 'recipe')

INSERT INTO tags VALUES (3, 'food')
INSERT INTO tags VALUES (3, 'spicy')
INSERT INTO tags VALUES (3, 'sweet')

查询

;WITH Aggregated_Tags AS (
    SELECT
        post,
        STRING_AGG(name, ',') AS name
    FROM tags
    GROUP BY post
)
SELECT post
FROM Aggregated_Tags
WHERE 
    (name LIKE '%food%' AND name LIKE '%spicy%' AND name NOT LIKE '%sweet%')
    OR (name LIKE '%recipe%')
GROUP BY post

如果我对你的理解正确的话，你正在寻找这样的东西。这里的关键是聚合每个 post 的标签，以消除生成多个 select 查询。这个解决方案并不完整，但我相信这是一个好的开始。

Answer 2

A GROUP BY HAVING COUNT 会起作用——而且速度快，用途广泛。一些例子：

CREATE TABLE tags(
    post_id INT,
    name VARCHAR(50),
    UNIQUE KEY (post_id, name)
);

INSERT INTO tags(post_id, name) VALUES
(1, 'foo'),
(1, 'bar'),

(2, 'foo'),

(3, 'bar'),

(4, 'baz'),

(5, 'foo'),
(5, 'bar'),
(5, 'meh');

-- posts tagged foo AND bar
-- returns 1, 5
SELECT post_id
FROM tags
GROUP BY post_id
HAVING COUNT(CASE WHEN name IN ('foo', 'bar') THEN 1 END) = 2;

-- posts tagged foo OR bar
-- returns 1, 2, 3, 5
SELECT post_id
FROM tags
GROUP BY post_id
HAVING COUNT(CASE WHEN name IN ('foo', 'bar') THEN 1 END) > 0;

-- posts tagged (foo AND bar) OR (baz)
-- returns 1, 4, 5
SELECT post_id
FROM tags
GROUP BY post_id
HAVING COUNT(CASE WHEN name IN ('foo', 'bar') THEN 1 END) = 2
OR     COUNT(CASE WHEN name IN ('baz') THEN 1 END) = 1;

-- posts tagged (foo AND bar) AND (no other tags)
-- returns 1
SELECT post_id
FROM tags
GROUP BY post_id
HAVING COUNT(CASE WHEN name IN ('foo', 'bar') THEN 1 END) = 2
AND    COUNT(*) = 2;

-- posts tagged (foo OR bar) AND NOT (meh)
-- returns 1, 2, 3
SELECT post_id
FROM tags
GROUP BY post_id
HAVING COUNT(CASE WHEN name IN ('foo', 'bar') THEN 1 END) > 0
AND    COUNT(CASE WHEN name IN ('meh') THEN 1 END) = 0;

Demo on DB<>Fiddle

将 tag1 AND tag2 OR tag3 等表达式转换为相应的 HAVING COUNT 不在我的回答中，但五个示例应该足够了。

具有逻辑操作的高性能 SQL 标签搜索查询

High performance SQL tag search query with logical operations

sql

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relational-division