PostgreSQL-返回查询结果和不同的可能值

假设我有一张这样的桌子：

CREATE TABLE item (
    id text NOT NULL,
    price integer NOT NULL,
    colors text[] DEFAULT ARRAY[]::text[],
    sizes text[] DEFAULT ARRAY[]::text[]
);

INSERT INTO item VALUES ('1', 100, array['red', 'blue', 'green'], array['s', 'l']);
INSERT INTO item VALUES ('2', 5000, array['yellow', 'green'], array['s']);
INSERT INTO item VALUES ('3', 300, array['red'], array['s', 'l', 'xl']);
INSERT INTO item VALUES ('4', 150, array['white'], array['xxl']);

数据如下：

CREATE TABLE item (
    id text NOT NULL,
    price integer NOT NULL,
    colors text[] DEFAULT ARRAY[]::text[],
    sizes text[] DEFAULT ARRAY[]::text[]
);

INSERT INTO item VALUES ('1', 100, array['red', 'blue', 'green'], array['s', 'l']);
INSERT INTO item VALUES ('2', 5000, array['yellow', 'green'], array['s']);
INSERT INTO item VALUES ('3', 300, array['red'], array['s', 'l', 'xl']);
INSERT INTO item VALUES ('4', 150, array['white'], array['xxl']);

现在假设我有这个查询：

SELECT * from item WHERE price > 50 AND price < 400 AND colors&&ARRAY['red'] AND sizes&&ARRAY['s', 'l', 'xxl'] ORDER BY price OFFSET 0 LIMIT 10;

我的问题是：如何更改查询以不仅返回此结果集，还返回此查询的所有可能大小（不包括任何大小条件），即不包括大小和数组['s'，'l'，'xxl']，此查询的所有可能颜色（不包括颜色条件），即不包括颜色和数组['red']价格范围只忽略查询中的价格条件，即不包括价格>50和价格<400？ 比如：

 | id | price | colors             | sizes      | p_sizes    | p_colors                          | min_price | max_price |
1| 1  | 100   | {red, blue, green} | {s, l}     | {s, l, xl} | {'red', 'blue', 'green', 'white'} | 100       | 300       |
1| 3  | 300   | {red}              | {s, l, xl} | {s, l, xl} | {'red', 'blue', 'green', 'white'} | 100       | 300       |

其中p_colors是查询的不同颜色列表：

SELECT * from item WHERE price > 50 AND price < 400 AND sizes&&ARRAY['s', 'l', 'xxl'] ORDER BY price OFFSET 0 LIMIT 10;

 | id | price | colors             | sizes
1| 1  | 100   | {red, blue, green} | {s, l}
1| 4  | 150   | {white}            | {xxl}
1| 3  | 300   | {red}              | {s, l, xl}

SELECT * from item WHERE price > 50 AND price < 400 AND colors&&ARRAY['red'] ORDER BY price OFFSET 0 LIMIT 10;

 | id | price | colors             | sizes
1| 1  | 100   | {red, blue, green} | {s, l}
1| 3  | 300   | {red}              | {s, l, xl}

SELECT * from item WHERE colors&&ARRAY['red'] AND sizes&&ARRAY['s', 'l', 'xxl'] ORDER BY price OFFSET 0 LIMIT 10;
 | id | price | colors             | sizes
1| 1  | 100   | {red, blue, green} | {s, l}
1| 3  | 300   | {red}              | {s, l, xl}

最小价格和最大价格是查询的价格范围：

SELECT * from item WHERE price > 50 AND price < 400 AND sizes&&ARRAY['s', 'l', 'xxl'] ORDER BY price OFFSET 0 LIMIT 10;

 | id | price | colors             | sizes
1| 1  | 100   | {red, blue, green} | {s, l}
1| 4  | 150   | {white}            | {xxl}
1| 3  | 300   | {red}              | {s, l, xl}

SELECT * from item WHERE price > 50 AND price < 400 AND colors&&ARRAY['red'] ORDER BY price OFFSET 0 LIMIT 10;

 | id | price | colors             | sizes
1| 1  | 100   | {red, blue, green} | {s, l}
1| 3  | 300   | {red}              | {s, l, xl}

SELECT * from item WHERE colors&&ARRAY['red'] AND sizes&&ARRAY['s', 'l', 'xxl'] ORDER BY price OFFSET 0 LIMIT 10;
 | id | price | colors             | sizes
1| 1  | 100   | {red, blue, green} | {s, l}
1| 3  | 300   | {red}              | {s, l, xl}

---编辑---

---

添加了尺寸条件，并将id为2的商品的价格更改为5000以澄清问题。

此查询选择预期值：

select 
    array(select distinct unnest(colors) from item) all_colors,
    array(select distinct unnest(sizes) from item) all_sizes,
    min(price) min_price,
    max(price) max_price
from item;

          all_colors           |  all_sizes   | min_price | max_price 
-------------------------------+--------------+-----------+-----------
 {yellow,blue,white,green,red} | {xl,s,l,xxl} |       100 |       300
(1 row)

您可以在横向联接中将查询结果与原始查询联接：

select * 
from item,
lateral (
    select 
        array(select distinct unnest(colors) from item) all_colors,
        array(select distinct unnest(sizes) from item) all_sizes,
        min(price) min_price,
        max(price) max_price
    from item
) sub
where price > 50 and price < 400 AND colors&&ARRAY['red'] order by price;

 id | price |      colors      |  sizes   |          all_colors           |  all_sizes   | min_price | max_price 
----+-------+------------------+----------+-------------------------------+--------------+-----------+-----------
 1  |   100 | {red,blue,green} | {s,l}    | {yellow,blue,white,green,red} | {xl,s,l,xxl} |       100 |       300
 3  |   300 | {red}            | {s,l,xl} | {yellow,blue,white,green,red} | {xl,s,l,xxl} |       100 |       300
(2 rows)    

您可以将聚合查询拆分为三个部分，以具有不同的where子句，例如：

select * 
from item,
lateral (
    select array(
        select distinct unnest(colors) 
        from item 
        where price > 50 and price < 400) all_colors) q1,
lateral (
    select array(
        select distinct unnest(sizes) 
        from item
        where price > 50 and price < 400 and colors && ARRAY['red']) all_sizes) q2,
lateral (
    select
        min(price) min_price,
        max(price) max_price
    from item
    where colors&&ARRAY['red']
) q3
where price > 50 and price < 400 and colors&&ARRAY['red'] order by price;

 id | price |      colors      |  sizes   |          all_colors           | all_sizes | min_price | max_price 
----+-------+------------------+----------+-------------------------------+-----------+-----------+-----------
 1  |   100 | {red,blue,green} | {s,l}    | {yellow,white,green,red,blue} | {l,s,xl}  |       100 |       300
 3  |   300 | {red}            | {s,l,xl} | {yellow,white,green,red,blue} | {l,s,xl}  |       100 |       300
(2 rows)    

---

这适用于需要表中所有可能值的情况，但我需要限制原始查询结果的可能性，修改为只忽略我需要的可能性所在的列。假设id为2的项目的价格为1000。因为它不是红色的，所以不会被选中，最大价格应该是300，而不是1000。这是否意味着我需要对每个字段进行新的查询？我不明白。如果您只想查询IDs1和ids3，那么所有的颜色都应该是{green，red，blue}，但是问题中有{'red'，blue'，green'，yellow'，white'，因为我不想只查询IDs1和ids3。要获得所有的颜色，我需要进行相同的查询，但没有颜色和数组['red']条件。这使得我们的价格只有>50和<400。在这种情况下，每件商品的价格恰好都在这个范围内。也许这是个坏例子。我将用更多的数据编辑这个问题。