将3个MySQL查询组合成1个查询
我正试图在我的网站上建立一个搜索功能。如果我想搜索照片的标题、文本或标签是否包含“黑色”一词,我有以下3个查询:将3个MySQL查询组合成1个查询,mysql,sql,select,Mysql,Sql,Select,我正试图在我的网站上建立一个搜索功能。如果我想搜索照片的标题、文本或标签是否包含“黑色”一词,我有以下3个查询: SELECT id FROM photos WHERE title LIKE '%black%' AND status = 'A' SELECT id FROM photos WHERE text LIKE '%black%' AND status = 'A' SELECT DISTINCT(photos.id) FROM photos, photo_tags, t
SELECT id
FROM photos
WHERE title LIKE '%black%'
AND status = 'A'
SELECT id
FROM photos
WHERE text LIKE '%black%'
AND status = 'A'
SELECT DISTINCT(photos.id)
FROM photos, photo_tags, tags
WHERE tags.tag LIKE '%black%'
AND photo_tags.keyid = tags.id
AND photos.id = photo_tags.catid
AND photos.status = 'A'
是否可以将所有这些合并到一个查询中?我知道我可以加入前两个,但是把它和第三个结合起来对我来说太复杂了。我曾尝试加入或,但我认为我做得不对
此外,我希望它没有重复的结果,所以如果一张照片的标题是“黑色”和标签是“黑色”,它只会出现一次
顺便说一句,表看起来像这样,keyid与tag.id相关,catid与photos.id相关
photos
+----+-----------+-----------------+
| id | title | text |
+----+-----------------------------+
| 1 | blue pic | black and blue |
| 2 | red pic | red and green |
| 3 | green pic | green and white |
| 4 | white pic | white and black |
| 5 | black pic | black and gold |
+----+-----------+-----------------+
tags
+----+-------+
| id | tag |
+----+-------+
| 1 | blue |
| 2 | table |
| 3 | chair |
| 4 | red |
| 5 | black |
+----+-------+
photo_tags
+-------+-------+
| keyid | catid |
+-------+-------+
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 2 |
| 5 | 5 |
+-------+-------+
似乎您应该加入这些表,然后根据在两个表中查找的文本进行筛选:
SELECT DISTINCT p.id FROM photos p
JOIN photo_tags pt ON pt.cat_id = p.id
JOIN tags t ON pt.key_id = t.id
WHERE (p.title LIKE '%black%' OR t.tag LIKE '%black%') AND p.status = 'A'
第一个查询是搜索标题列,第二个查询是搜索文本列。我知道将这两个查询合并成一个查询并不太困难,但这是第三个查询的添加,这让我很困惑——我知道有一个简单的查询!我在WHERE中添加了“或类似于“%black%”的p.text,它就像一个符咒一样有效-非常感谢
First statement could be your answer. Not sure if you are looking for below output:-
ysql> SELECT DISTINCT(photos.id) FROM photos, photo_tags, tags WHERE tags.tag L
IKE '%black%'AND photos.title LIKE '%black%' AND photo_tags.keyid = tags.id AND
photos.id = photo_tags.catid;
+------+
| id |
+------+
| 5 |
+------+
1 row in set (0.05 sec)
mysql> SELECT id
-> FROM photos
-> WHERE title LIKE '%black%' ;
+------+
| id |
+------+
| 5 |
+------+
1 row in set (0.08 sec)
mysql> SELECT id
-> FROM photos
-> WHERE text LIKE '%black%';
+------+
| id |
+------+
| 1 |
| 4 |
| 5 |
+------+
3 rows in set (0.00 sec)
mysql> SELECT DISTINCT(photos.id)
-> FROM photos, photo_tags, tags
-> WHERE tags.tag LIKE '%black%'
-> AND photo_tags.keyid = tags.id
-> AND photos.id = photo_tags.catid ;
+------+
| id |
+------+
| 5 |
+------+
1 row in set (0.05 sec)
mysql> SELECT DISTINCT(photos.id) FROM photos, photo_tags, tags WHERE tags.tag L
IKE '%black%'AND photos.title LIKE '%black%' AND photo_tags.keyid = tags.id AND
photos.id = photo_tags.catid;
+------+
| id |
+------+
| 5 |
+------+
1 row in set (0.05 sec)