3

我有这个数据表：

+-----+-----------+------------------------------------+---------+
| ID  | post_type | name                               | term_id |
+-----+-----------+------------------------------------+---------+
| 278 | supplier  | Heating                            |      15 |
| 282 | supplier  | Central Heating                    |      16 |
| 278 | supplier  | Biomass                            |      17 |
| 278 | supplier  | Ground Source Heat Pumps           |      18 |
| 278 | supplier  | Passive Solar                      |      19 |
| 282 | supplier  | Air Source Heat Pumps              |      21 |
| 278 | supplier  | Air Conditioning                   |      22 |
| 278 | supplier  | Boilers                            |      23 |
| 277 | supplier  | Lighting                           |      25 |
| 277 | supplier  | LED's                              |      26 |
| 282 | supplier  | Halogen                            |      28 |
| 277 | supplier  | CFL                                |      29 |
| 282 | supplier  | Sustainable Construction Materials |      31 |
| 282 | supplier  | Plaster                            |      33 |
| 282 | supplier  | Floors                             |      37 |
| 282 | supplier  | Water                              |      38 |
| 282 | supplier  | Showers & Baths                |      43 |
| 278 | supplier  | Cooling                            |      44 |
| 278 | supplier  | Refrigeration                      |      46 |
| 282 | supplier  | Passive Design                     |      47 |
| 278 | supplier  | Chillers                           |      48 |
| 282 | supplier  | Renewable Energy                   |      49 |
| 282 | supplier  | Air Source Heat Pumps              |      53 |
| 282 | supplier  | Biomass Heating                    |      55 |
| 282 | supplier  | Biofuels                           |      57 |
| 282 | supplier  | Insulation                         |      61 |
| 282 | supplier  | Wall                               |      63 |
| 282 | supplier  | Floor                              |      64 |
| 282 | supplier  | Draught Proofing                   |      65 |
| 282 | supplier  | Energy Efficiency                  |      70 |
| 282 | supplier  | Gas Boiler Management Systems      |      71 |
| 282 | supplier  | Low Energy Lighting                |      72 |
| 282 | supplier  | Voltage Control                    |      73 |
| 282 | supplier  | Smart Meters                       |      74 |
| 282 | supplier  | Electric Heating                   |      75 |
+-----+-----------+------------------------------------+---------+

并且需要提取ID适用于指定name（通配符字符串）和term_id（整数）的 s 列表。因此，例如，我将搜索ID具有 aname LIKE '%Lighting%'和 a term_id = 26...应该返回的 s ID 277。

以下查询有效但不漂亮：

SELECT a.ID, d.name, d.term_id
FROM cn_posts AS a
INNER JOIN cn_postmeta AS b ON a.ID = b.post_id
INNER JOIN cn_term_relationships AS c ON a.ID = c.object_id
INNER JOIN cn_terms AS d ON c.term_taxonomy_id = d.term_id
WHERE a.post_status = 'publish'
AND d.name LIKE '%Lighting%'
AND a.ID IN (
    SELECT a.ID
    FROM cn_posts AS a
    INNER JOIN cn_postmeta AS b ON a.ID = b.post_id
    INNER JOIN cn_term_relationships AS c ON a.ID = c.object_id
    INNER JOIN cn_terms AS d ON c.term_taxonomy_id = d.term_id
    WHERE d.term_id = '26'
)
GROUP BY a.ID

我尝试了以下查询，但它们都没有返回任何结果：

SELECT DISTINCT a.ID, d.name, d.term_id
FROM cn_posts AS a
LEFT JOIN cn_postmeta AS b ON a.ID = b.post_id
LEFT JOIN cn_term_relationships AS c ON a.ID = c.object_id
LEFT JOIN cn_terms AS d ON c.term_taxonomy_id = d.term_id
WHERE a.post_status = 'publish'
AND d.name LIKE '%Lighting%'
AND d.term_id = '26'

SELECT a.ID, d.name, d.term_id, a.post_status
FROM cn_posts AS a
JOIN cn_postmeta AS b ON a.ID = b.post_id
JOIN cn_term_relationships AS c ON a.ID = c.object_id 
JOIN cn_terms AS d ON c.term_taxonomy_id = d.term_id
WHERE a.post_status = 'publish'
AND d.name LIKE '%Lighting%'
AND d.term_id = '26'
GROUP BY a.ID

这些都返回帖子：

SELECT a.ID, d.name, d.term_id, a.post_status
FROM cn_posts AS a
JOIN cn_postmeta AS b ON a.ID = b.post_id
JOIN cn_term_relationships AS c ON a.ID = c.object_id 
JOIN cn_terms AS d ON c.term_taxonomy_id = d.term_id
WHERE a.post_status = 'publish'
AND d.name LIKE '%Lighting%'

SELECT a.ID, d.name, d.term_id, a.post_status
FROM cn_posts AS a
JOIN cn_postmeta AS b ON a.ID = b.post_id
JOIN cn_term_relationships AS c ON a.ID = c.object_id 
JOIN cn_terms AS d ON c.term_taxonomy_id = d.term_id
WHERE a.post_status = 'publish'
AND d.term_id = '26'

但是，当您在查询中同时包含 name 和 term_id 时，它什么也不返回？

4

6 回答 6

1

显然，表（您的数据样本）中没有任何一行符合d.name LIKE '%Lighting%' AND d.term_id = '26'. 有匹配第一部分的行和匹配第二部分的行，但没有一个匹配两者。但是，如果将其作为一组行，则ID = 277确实匹配条件。因此，您需要在 HAVING 子句中引入分组并应用条件，尽管稍作修改，如下所示：

SELECT a.ID
FROM cn_posts AS a
INNER JOIN cn_postmeta AS b ON a.ID = b.post_id
INNER JOIN cn_term_relationships AS c ON a.ID = c.object_id
INNER JOIN cn_terms AS d ON c.term_taxonomy_id = d.term_id
WHERE a.post_status = 'publish'
GROUP BY a.ID
HAVING COUNT(d.name LIKE '%Lighting%' OR NULL) > 0
   AND COUNT(d.term_id = '26'         OR NULL) > 0
;

但是请注意，这意味着您无法在同一查询中获取与 ID 类似d.name或旁边的详细信息（但在这种情况下，可以d.term从中提取其他列）。a如果d在同一查询中返回列对于解决您的问题是强制性的，那么您可能需要在几乎相同的查询中将上述内容用作派生表，以提取您需要的所有数据。在这种情况下，派生表将用作过滤 ID 集以仅匹配两个条件的 ID 集的一种方式。在该主查询中，这两个条件需要与OR而不是与连接AND，如下所示：

SELECT a.ID, d.name, d.term_id
FROM cn_posts AS a
INNER JOIN cn_postmeta AS b ON a.ID = b.post_id
INNER JOIN cn_term_relationships AS c ON a.ID = c.object_id
INNER JOIN cn_terms AS d ON c.term_taxonomy_id = d.term_id
WHERE a.post_status = 'publish'
AND (d.name LIKE '%Lighting%' OR d.term_id = '26')
AND a.ID IN (
    /* the above query, now used just as a filter */
    SELECT a.ID
    FROM cn_posts AS a
    INNER JOIN cn_postmeta AS b ON a.ID = b.post_id
    INNER JOIN cn_term_relationships AS c ON a.ID = c.object_id
    INNER JOIN cn_terms AS d ON c.term_taxonomy_id = d.term_id
    WHERE a.post_status = 'publish'
    GROUP BY a.ID
    HAVING COUNT(d.name LIKE '%Lighting%' OR NULL) > 0
       AND COUNT(d.term_id = '26'         OR NULL) > 0
)
;

显然，这几乎不会比您最终得到的查询更好。

于 2012-09-24T15:14:25.217 回答
0 
SELECT a.ID, d.name, d.term_id 
FROM cn_posts AS a 
INNER JOIN cn_postmeta AS b ON a.ID = b.post_id 
INNER JOIN cn_term_relationships AS c ON a.ID = c.object_id 
INNER JOIN cn_terms AS d ON c.term_taxonomy_id = d.term_id 
INNER JOIN cn_terms AS d2 ON c.term_taxonomy_id = d2.term_id 
WHERE a.post_status = 'publish' 
AND d.name LIKE '%Lighting%' 
AND d2.term_id = '26'

Since your conditions are on different rows, you have to join to the cn_terms twice.

于 2012-09-24T14:31:00.800 回答
0

经过大家的帮助（非常感谢！！）我最终只使用了这个查询，它不是最干净的，但唯一一个得到了我所追求的结果，我需要让工作开始。

还匹配帖子标题和描述上的关键字以及服务名称。

SELECT a.ID, a.post_title, a.post_status, d.name, d.term_id
FROM cn_posts AS a
JOIN cn_postmeta AS b ON a.ID = b.post_id
JOIN cn_term_relationships AS c ON a.ID = c.object_id
JOIN cn_terms AS d ON c.term_taxonomy_id = d.term_id
WHERE a.post_status = 'publish'
AND ( a.post_title LIKE '%Lighting%' OR a.post_content LIKE '%Lighting%' OR d.name LIKE '%Lighting%' )
AND a.ID IN (
    SELECT a.ID FROM cn_posts AS a
    INNER JOIN cn_postmeta AS b ON a.ID = b.post_id
    INNER JOIN cn_term_relationships AS c ON a.ID = c.object_id
    INNER JOIN cn_terms AS d ON c.term_taxonomy_id = d.term_id
    WHERE d.term_id = '26' )
GROUP BY a.ID

非常感谢你们的帮助。显然，如果您能弄清楚为什么其他查询不起作用或者可以清理这个查询，请随时回复。

戴夫

于 2012-09-24T14:24:34.960 回答
0

你试过这个吗？

SELECT a.ID, d.name, d.term_id
FROM cn_posts AS a
INNER JOIN cn_postmeta AS b ON a.ID = b.post_id
INNER JOIN cn_term_relationships AS c ON a.ID = c.object_id 
INNER JOIN cn_terms AS d ON c.term_taxonomy_id = d.term_id
WHERE a.post_status = 'publish'
AND d.name LIKE '%Lighting%'
AND d.term_id = '28'
GROUP BY a.ID
于 2012-09-24T11:26:10.920 回答
0

不能这个简单的选择不会满足你的需要。

select ID, name, term_id from yourtable where name LIKE '%Lighting%' and a term_id = 26
于 2012-09-24T13:27:53.200 回答
0 
SELECT a.ID, d.name, d.term_id, a.post_status
FROM wp_posts AS a
JOIN wp_postmeta AS b ON a.ID = b.post_id
JOIN wp_term_relationships AS c ON a.ID = c.object_id 
JOIN wp_terms AS d ON c.term_taxonomy_id = d.term_id
WHERE a.post_status = 'publish'
AND d.name LIKE '%Halogen%'
AND d.term_id = '25'
GROUP BY a.ID
于 2012-09-24T11:29:33.257 回答