Question

所以我有多个表，我必须在查询时合并，但join和union似乎没有实现我的对象

联：

mysql> SELECT NAME, currentstatus, NULL AS username, NULL AS status FROM statustable WHERE Name like '%ahsan%' UNION ALL SELECT NULL AS NAME, NULL AS currentstatus, username, status from awsaccount WHERE username like '%ahsan%';
+--------------+-------------------+----------+--------------------------------+
| NAME         | currentstatus     | status   | username                         |
+--------------+-------------------+----------+--------------------------------+
| Ahsan Naseem | activated         | NULL     | NULL                           |
| NULL         | NULL              | ACTIVE   | ahsan.naseem       |
| NULL         | NULL              | INACTIVE | ahsantest                      |
| NULL         | NULL              | ACTIVE   | ahsantest2                     |
| NULL         | NULL              | ACTIVE   | ahsantestuserprofileupdate     |
| NULL         | NULL              | INACTIVE | ahsantestuserprofileupdate_cli |
| NULL         | NULL              | INACTIVE | decent.ahsan         |
| NULL         | NULL              | INACTIVE | decent.ahsan_cli               |
+--------------+-------------------+----------+--------------------------------+
8 rows in set (0.00 sec)

加入：

mysql> select * from (select * from statustable where Name like '%ahsan%') as ab   JOIN  (select * from awsaccount where  username like '%ahsan%') as asb;                                                                       
    +--------------+-------------------+--------------------------------+----------+
    | Name         | currentstatus | username                       | status   |
    +--------------+-------------------+--------------------------------+----------+
    | Ahsan Naseem | activated         | ahsan.naseem                    | ACTIVE   |
    | Ahsan Naseem | activated         | ahsantest                      | INACTIVE |
    | Ahsan Naseem | activated         | ahsantest2                     | ACTIVE   |
    | Ahsan Naseem | activated         | ahsantestuserprofileupdate     | ACTIVE   |
    | Ahsan Naseem | activated         | ahsantestuserprofileupdate_cli | INACTIVE |
    | Ahsan Naseem | activated         | decent.ahsan         | INACTIVE |
    | Ahsan Naseem | activated         | decent.ahsan_cli               | INACTIVE |
    +--------------+-------------------+--------------------------------+----------+
    7 rows in set (0.00 sec)

我想要实现的目标是：

+--------------+-------------------+----------+--------------------------------+
| NAME         | currentstatus    | status   | username                       |
+--------------+-------------------+----------+--------------------------------+
| Ahsan Naseem | Active            | ACTIVE   | ahsan.naseem        |
| NULL         | NULL              | INACTIVE | ahsantest                      |
| NULL         | NULL              | ACTIVE   | ahsantest2                     |
| NULL         | NULL              | ACTIVE   | ahsantestuserprofileupdate     |
| NULL         | NULL              | INACTIVE | ahsantestuserprofileupdate_cli |
| NULL         | NULL              | INACTIVE | decent.ahsan        |
| NULL         | NULL              | INACTIVE | decent.ahsan_cli               |
+--------------+-------------------+----------+--------------------------------+

这真的有可能吗？我是sql的新手，非常感谢您的建议和建议

Answer 1

请在将来提供表格定义和示例数据，这样您的问题就更有可能迅速得到有用的答案。以下是我为这些目的而做的数据，只是做了一些更改，以便我回答您的问题：

DROP TABLE IF EXISTS statustable;
CREATE TABLE statustable(`NAME` VARCHAR(32), currentStatus VARCHAR(32));

INSERT INTO statustable VALUES('Ahsan Naseem', 'activated');

DROP TABLE IF EXISTS awsaccount;
CREATE TABLE awsaccount(`NAME` VARCHAR(32), username VARCHAR(32), `status` VARCHAR(32), logEntry DATETIME);

INSERT INTO awsaccount VALUES('Ahsan Naseem', 'ACTIVE', 'ahsan.naseem', '2000-01-07'),
    ('Ahsan Naseem', 'INACTIVE', 'ahsantest', '2000-01-06'),
    ('Ahsan Naseem', 'ACTIVE', 'ahsantest2', '2000-01-05'),
    ('Ahsan Naseem', 'ACTIVE', 'ahsantestuserprofileupdate', '2000-01-04'),
    ('Ahsan Naseem', 'INACTIVE', 'ahsantestuserprofileupdate_cli', '2000-01-03'),
    ('Ahsan Naseem', 'INACTIVE', 'decent.ahsan', '2000-01-02'),
    ('Ahsan Naseem', 'INACTIVE', 'decent.ahsan_cli', '2000-01-01');

据我可以从您的示例查询中看出，这里有两个问题，首先在两个表中似乎都不是公共密钥，这是一个值与两个表中要匹配的行（加入/ JOIN）相同，并且对于彼此相关的行是相同的。（顺便说一句，这些也应该是相同的数据类型或查询可能需要很长时间才能执行）。我在NAME表中添加了awsaccount列，以便在此上下文中设置JOIN。由此结果如下：

SELECT A.`NAME`, A.currentStatus, B.username, B.`status` FROM
  statusTable A 
RIGHT OUTER JOIN 
  awsaccount B 
ON A.`NAME` = B.`NAME`;

+--------------+---------------+----------+--------------------------------+
| NAME         | currentStatus | username | status                         |
+--------------+---------------+----------+--------------------------------+
| Ahsan Naseem | activated     | ACTIVE   | ahsan.naseem                   |
| Ahsan Naseem | activated     | INACTIVE | ahsantest                      |
| Ahsan Naseem | activated     | ACTIVE   | ahsantest2                     |
| Ahsan Naseem | activated     | ACTIVE   | ahsantestuserprofileupdate     |
| Ahsan Naseem | activated     | INACTIVE | ahsantestuserprofileupdate_cli |
| Ahsan Naseem | activated     | INACTIVE | decent.ahsan                   |
| Ahsan Naseem | activated     | INACTIVE | decent.ahsan_cli               |
+--------------+---------------+----------+--------------------------------+
7 rows in set (0.00 sec)

哪个更接近您的要求但不完全相同，因为NAME键对于两个表中的所有条目都是通用的。要在问题中产生输出，还需要更多步骤，并且我做了以下假设：

awsaccout表是某些用户以前的accout雕像的历史记录
为此，我添加了一个DATE字段，可用于控制此表中条目的顺序

结果如下：

JOIN

正如您提到的SQL新手，这里有一个图像可以直观地解释import networkx as nx G = nx.path_graph(5) path = nx.single_source_shortest_path_length(G ,source=src_vertex,cutoff=2)的不同种类（取自here）。

此致

詹姆斯

连接没有重复行/ NULL值的表

1 个答案: