MySQL：根据另一个表中的值过滤选择的值

Question

I have a table as following:

User tables

[id] | [name] | [gender] | [phone]    
1    | David  | M        | 12345678 
2    | Mary   | F        | 18345679 
3    | Joe    | M        | 12845670 
4    | John   | M        | 12345671 
5    | May    | F        | 16355672 

And another table

Access_Control tables

[company] | [access_allowed]
Company A | gender 
Company A | phone
Company A | name
Company B | name
Company C | gender
Company C | phone

Question : A want a view like the following only using SQL

[uid]| [name] | [gender] | [phone]  | [owned]
1    | David  | M        | 12345678 | Company A
2    | Mary   | F        | 18345679 | Company A
3    | Joe    | M        | 12845670 | Company A
4    | John   | M        | 12345671 | Company A
5    | May    | F        | 16355672 | Company A  
1    | David  | N/A      | N/A      | Company B
2    | Mary   | N/A      | N/A      | Company B
3    | Joe    | N/A      | N/A      | Company B
4    | John   | N/A      | N/A      | Company B
5    | May    | N/A      | N/A      | Company B 
1    | N/A    | M        | 12345678 | Company C
2    | N/A    | F        | 18345679 | Company C
3    | N/A    | M        | 12845670 | Company C
4    | N/A    | M        | 12345671 | Company C
5    | N/A    | F        | 16355672 | Company C 

Access_Control tables schema can be changed if needed.

This is easy to do with conjunction to a server side language, but is this possible with just SQL? Thanks!

Answer 1

After 3 months, I am finally able to answer my own question, the solution is a bit dirty but it does the job and run very fast.

---

Step 1: Change the Access_Control to a vertical view

CREATE VIEW `access_control_vertical` AS
    SELECT 
        `access_control`.`company` AS `company`,
        BIT_OR((CASE
            WHEN (`access_control`.`access_allowed` = 'gender') THEN 1
            ELSE 0
        END)) AS `gender`,
        BIT_OR((CASE
            WHEN (`access_control`.`access_allowed` = 'name') THEN 1
            ELSE 0
        END)) AS `name`,
        BIT_OR((CASE
            WHEN (`access_control`.`access_allowed` = 'phone') THEN 1
            ELSE 0
        END)) AS `phone`
    FROM
        `access_control`
    GROUP BY `access_control`.`company`

Result 1:

company gender name phone
A       1       1   1
B       0       1   0
C       1       0   1

---

Step 2: Use cases to filter out which company can have which parameter from user

CREATE VIEW `filtered_user` AS
    SELECT 
        `access_control_vertical`.`company` AS `company`,
        (CASE
            WHEN (`access_control_vertical`.`gender` = 1) THEN `user`.`gender`
            ELSE 'N/A'
        END) AS `gender`,
        (CASE
            WHEN (`access_control_vertical`.`gender` = 1) THEN `user`.`name`
            ELSE 'N/A'
        END) AS `name`,
        (CASE
            WHEN (`access_control_vertical`.`gender` = 1) THEN `user`.`phone`
            ELSE 'N/A'
        END) AS `phone`
    FROM
        (`user`
        JOIN `access_control_vertical` ON ((1 = 1)))

Result 2:

company, gender, name, phone
'A', 'M', 'David', '12345678'
'A', 'F', 'Mary   ', '18345679'
'A', 'M', 'Joe    ', '12845670'
'A', 'M', 'John   ', '12345671'
'A', 'F', 'May    ', '16355672'
'B', 'N/A', 'N/A', 'N/A'
'B', 'N/A', 'N/A', 'N/A'
'B', 'N/A', 'N/A', 'N/A'
'B', 'N/A', 'N/A', 'N/A'
'B', 'N/A', 'N/A', 'N/A'
'C', 'M', 'David', '12345678'
'C', 'F', 'Mary   ', '18345679'
'C', 'M', 'Joe    ', '12845670'
'C', 'M', 'John   ', '12345671'
'C', 'F', 'May    ', '16355672'

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