我有什么
我有多个这样的表:
- tbl_hw_inventar(hw_id,hostname,hw_typ_idfs,hw_created_user_idfs等...)
- tbl_hw_typ(hw_typ_id,hw_typ_title等......)
- tbl_user(user_id,username等等)
- tbl_hw_edited(hw_edited_id,hw_edited_client_idfs,hw_edited_date,hw_edited_user_idfs)
我需要什么
我希望输出一个包含以下信息的表:
hw_id | Hostname | created | last edited
12315 | client-01 | 2015-05-06 15:31:06 (username) | 2015-07-02 09:46:17 (username) |
问题
正如您所看到的,我可以通过外键和内部联接获取hw_typ等信息到" tbl_hw_typ
&# 34 ;.对于" hw_created_user_idfs
"的信息也是如此。以及内部联接以获取用户ID 的用户名。
但我怎样才能获得上次修改,日期时间和用户名?
在我的表格中#34; tbl_hw_edited
"我有这样的条目:
row id | hw_id | datetime | user_id
代码
到目前为止,我的SQL查询看起来像这样:
SELECT `tbl_hw_inventar`.*, `tbl_hw_typ`.`hw_typ_title`, `tbl_user`.`username`, `tbl_hw_edited`.`hw_edited_id`
FROM `tbl_hw_inventar`
INNER JOIN `tbl_hw_typ`
ON `tbl_hw_inventar`.`hw_typ_idfs` = `tbl_hw_typ`.`hw_typ_id`
INNER JOIN `tbl_user`
on `tbl_hw_inventar`.`hw_create_user_idfs` = `tbl_user`.`id`
JOIN (
SELECT MAX(`tbl_hw_edited`.`hw_edited_id`), `tbl_hw_edited`.`hw_edited_client_idfs`
FROM `tbl_hw_edited`
) `tbl_hw_edited` ON `tbl_hw_inventar`.`hw_id` = `tbl_hw_edited`.`hw_edited_client_idfs`
ORDER BY `tbl_hw_inventar`.`hw_id` ASC
那么如何导出信息呢?看起来我必须在查询中创建一个子查询。但是每次尝试都失败了。
感谢您的帮助
修改
正如我所建议的,我为每个表提供了更多信息(表格数据):
-tbl_hw_inventar-
| hw_id | hw_hostname | hw_create_date | hw_create_user_idfs |
| 1 | client-01 | 2015-03-06 11:57:42 | 1 |
| 2 | client-02 | 2015-09-21 21:17:00 | 3 |
-tbl_hw_edited-
| hw_edited_id | hw_edited_client_idfs | hw_edited_date | hw_edited_user_idfs |
| 1 | 1 | 2015-09-24 17:30:22 | 1 |
| 2 | 2 | 2015-09-24 16:33:22 | 2 |
| 3 | 1 | 2015-09-24 23:30:22 | 2 |
| 4 | 2 | 2015-09-24 20:30:22 | 3 |
-tbl_user-
| id | username |
| 1 | ismaelw |
| 2 | skalb |
| 3 | yrumpel |
因此,作为最终结果,我需要这样的输出:
| hw_id | hostname | created | edited |
| 1 | client-01 | 2015-03-06 11:57:42 (ismaelw) | 2015-09-24 23:30:22 (skalb) |
答案 0 :(得分:1)
如果我正确解释了你的表,你需要找到每个hw_edited_client_idfs(加入hw_id)的最大值(编辑日期)
SELECT
het.*
FROM tbl_hw_edited AS het
INNER JOIN (
SELECT
hw_edited_client_idfs
, MAX(hw_edited_date) AS last_edit_dt
FROM tbl_hw_edited
GROUP BY hw_edited_client_idfs
) AS mx ON het.hw_edited_client_idfs = mx.hw_edited_client_idfs
AND het.hw_edited_date = mx.last_edit_dt
使用该结果,您可以将其加入源表,以发现哪个用户与最大值(编辑日期)相关联
SELECT
i.hw_id
, i.hw_hostname
, uc.username created_by
, he.hw_edited_date last_edit_date
, ue.username last_edit_by
FROM tbl_hw_inventar AS i
INNER JOIN tbl_user AS uc ON i.hw_create_user_idfs = uc.id
LEFT OUTER JOIN (
SELECT
het.*
FROM tbl_hw_edited AS het
INNER JOIN (
SELECT
hw_edited_client_idfs
, MAX(hw_edited_date) AS last_edit_dt
FROM tbl_hw_edited
GROUP BY hw_edited_client_idfs
) AS mx ON het.hw_edited_client_idfs = mx.hw_edited_client_idfs
AND het.hw_edited_date = mx.last_edit_dt
) AS he ON i.hw_id = he.hw_edited_client_idfs
LEFT OUTER JOIN tbl_user AS ue ON he.hw_edited_user_idfs = ue.id
然后使用这样的结果:
| hw_id | hw_hostname | username | hw_edited_date | username |
|-------|-------------|----------|-----------------------------|----------|
| 1 | client-01 | ismaelw | September, 24 2015 23:30:22 | skalb |
| 2 | client-02 | yrumpel | September, 24 2015 20:30:22 | yrumpel |
产生这个结果:
def myfunction():
for file in files:
myfun(file, Temp=True)