MySQL查询帮助 - 需要

Question

表：taxonomy_term_data

tid name 
7  desert 
10 indian 

表：taxonomy_index

nid tid 
13  7 
10  7 
10  10 
12  7 
14  10 

我需要一个mysql查询来获取其中有 “沙漠”，也是 “印度” 的NID。 这里的输出是nid = 10。 有人可以帮助写入查询。我只是一个初学者

Answer 1

SELECT nid 
FROM taxonomy_index 
JOIN taxonomy_term_data USING (tid) 
WHERE name IN ('desert', 'indian') 
GROUP BY nid 
HAVING COUNT(DISTINCT tid) = 2 

看到它联机工作：sqlfiddle

Answer 2

你可以通过GROUP BY这个答案和HAVING：

SELECT nid 
FROM taxonomy_index 
WHERE tid IN (7, 10) 
GROUP BY nid 
HAVING COUNT(*) > 1 

Answer 3

假设(nid, tid)组合是唯一的：

SELECT ta.nid 
FROM taxonomy_index AS ta 
    JOIN taxonomy_index AS tb 
    ON tb.nid = ta.nid 
WHERE ta.tid = 7 
    AND tb.tid = 10 

Answer 4

你可以用各种SQL书写风格如下：

1.

SELECT DISTINCT(i.nid) 
FROM taxonomy_index i 
INNER JOIN taxonomy_term_data d 
ON i.tid = d.tid 
AND (d.name = 'desert' 
OR d.name = 'indian') 

2.

SELECT i.nid 
FROM taxonomy_index i 
INNER JOIN taxonomy_term_data d 
ON i.tid = d.tid 
AND (d.name = 'desert' 
OR d.name = 'indian') 
GROUP BY nid 

3.

SELECT i.nid 
FROM taxonomy_index i, taxonomy_term_data d 
WHERE i.tid = d.tid 
AND d.name IN ('desert', 'indian') 
GROUP BY nid 

4.

SELECT DISTINCT(nid) 
FROM taxonomy_index 
WHERE (tid = 7 
OR tid = 12)