php - 从同一张表中选择不同的结果

我在帖子表中有以下结构（示例）：

id | id_author | content | date | ft
1  | 1         | hi!     | 2016 | 2
2  | 1         | hello!  | 2016 | 3
3  | 1         | welcome | 2016 | 1
4  | 1         | test!   | 2016 | 2

我有query：

SELECT id, id_author, content, date, ft FROM post where id_author = '$author' ORDER BY id DESC LIMIT 7

但是，我也需要用select用您各自的ft来帖子。像这样：

SELECT id, id_author, content, date, ft FROM post where id_author = '$author' and ft = 1 ORDER BY id DESC LIMIT 4

SELECT id, id_author, content, date, ft FROM post where id_author = '$author' and ft = 2 ORDER BY id DESC LIMIT 4

SELECT id, id_author, content, date, ft FROM post where id_author = '$author' and ft = 3 ORDER BY id DESC LIMIT 4

我可以用LIMIT 4做ft的“过滤器”，例如：

foreach($query as $ex) {
    switch($ex["ft"]) {
        ...
    }
}

但是，我的第一个foreach需要具有query，而LIMIT 7的querys实境需要从所有帖子中选择最后4个结果。

怎么做而不必做倍数ft？

编辑：

我需要在一个querys中显示最后7个帖子（常规），在另一个div中显示带有图像（ft = 1）的最后4个帖子，在另一个div中显示带有提及（ft = 2）的最后4个帖子最后4个帖子在另一个div中带有标签（ft = 3）。

最佳答案

您可以使用UNION运算符执行此操作。

SELECT
    'General' AS post_type,
    id,
    id_author,
    content,
    date,
    ft
FROM
    Post
WHERE
    id_author = '$author'
ORDER BY
    id DESC
LIMIT 7
UNION ALL
SELECT
    'Image' AS post_type,
    id,
    id_author,
    content,
    date,
    ft
FROM
    Post
WHERE
    id_author = '$author' AND
    ft = 1
ORDER BY
    id DESC
LIMIT 4
UNION ALL
SELECT
    'Mentions' AS post_type,
    id,
    id_author,
    content,
    date,
    ft
FROM
    Post
WHERE
    id_author = '$author' AND
    ft = 2
ORDER BY
    id DESC
LIMIT 4
UNION ALL
SELECT
    'Hashtags' AS post_type,
    id,
    id_author,
    content,
    date,
    ft
FROM
    Post
WHERE
    id_author = '$author' AND
    ft = 3
ORDER BY
    id DESC
LIMIT 4

关于php - 从同一张表中选择不同的结果，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/35211239/