Question

in MySql database I have to make some little tricky query.
I must get result only in TWO COLUMNS (TYPE (PROJECT,SUPPORT,EDUCATION) and VALUE (60 and 40 on example))

I have static table which contains types:

T1

ID  TYPE
1   PROJECT
2   PROJECT
3   PROJECT
4   SUPPORT
5   EDUCATION

I have static table T2 with all tasks that has value of some of the type:

    T2

  TASK    T1ID

    1      1
    2      1
    3      2
    4      3 
    5      4
    6      5

T3 is DYNAMIC table of created tasks with some IDS.

T3 

ID
1
2
3
4
5
6

T4 table has information who created those tasks.

T4

T3ID     Name
1       Bob Marley
2       Bob Marley
3       Bob Marley
4       Bob Marley
5       Tom Cruise
6       Bob Marley

and finally T5 contains info from T2 and T3

T5

TASK    T3ID
  1       1
  2       2
  3       3
  5       4
  1       5
  5       6

For some specific person (always one person- in this example Bob Marley or Tom Cruise)
I must haave statistics in PERCENTAGE how many they worked on PROJECTS or SUPPORT or EDUCATION.

So I will select Bob Marley- his T3ID is 1,2,3,4 and 6.

In table 5 his tasks ID are are 1,2,3,5 and again 5.

So when I look in table T2 his T1 IDs are 1,1,2,4 and 4.
It means that Bob Marley worked on 3 PROJECTS and 2 SUPPORT Tasks.

So when I select Bob Marley result should be:

PROJECT  60
SUPPORT  40

This is the final result from query.
How can I achieve this?
I know that it must be a couple of JOIN statements and of course you can use in WHERE clause

where name='Bob Marley'

If I put

 `where name=Tom Cruise

result should be

PROJECT 100`

Thank you

Answer 1

I think this is what you are looking for:

SELECT 
  t4.Name,
  SUM(CASE WHEN t1.type = 'PROJECT'   THEN 1 ELSE 0 END) * 100 / COUNT(t1.type) Project,
  SUM(CASE WHEN t1.type = 'SUPPORT'   THEN 1 ELSE 0 END) * 100 / COUNT(t1.type) SUPPORT,
  SUM(CASE WHEN t1.type = 'EDUCATION' THEN 1 ELSE 0 END) * 100 / COUNT(t1.type) Education
FROM T1
INNER JOIN T2 ON t1.ID = t2.T1ID
INNER JOIN t5 ON t2.task = t5.task
INNER JOIN t3 ON t3.id = t5.t3id
INNER JOIN t4 ON t3.Id = t4.t3id
GROUP BY t4.Name;

SQL Fiddle Demo

This will give you:

|       NAME | PROJECT | SUPPORT | EDUCATION |
----------------------------------------------
| Bob Marley |      60 |      40 |         0 |
| Tom Cruise |     100 |       0 |         0 |

for the sample data you posted.

Note that: This will give you only the Name that was involved in projects and tasks. You might need to OUTER JOIN(LEFT or RIGHT) the table instead of INNER JOIN to include those Names that were not involved in any tasks or projects (the unmatched rows), with IFNULL() to replaces NULLs with zeros.

---

Update:

You can use the CONCAT() function to do this, but it will be easier and more readable if you include the previous query inside a subquery and do this in an outer query like so:

SELECT
  Name,
  CONCAT(CAST(project   AS DECIMAL(10, 2)), ' AND ', 
         CAST(support   AS DECIMAL(10, 2)), ' AND ', 
         CAST(education AS DECIMAL(10, 2))) AS Percentage
FROM
(
  SELECT 
    t4.Name,
    SUM(CASE WHEN t1.type = 'PROJECT' THEN 1 ELSE 0 END) * 100 / COUNT(t1.type) Project,
    SUM(CASE WHEN t1.type = 'SUPPORT' THEN 1 ELSE 0 END) * 100 / COUNT(t1.type) SUPPORT,
    SUM(CASE WHEN t1.type = 'EDUCATION' THEN 1 ELSE 0 END) * 100 / COUNT(t1.type) Education
  FROM T1
  INNER JOIN T2 ON t1.ID = t2.T1ID
  INNER JOIN t5 ON t2.task = t5.task
  INNER JOIN t3 ON t3.id = t5.t3id
  INNER JOIN t4 ON t3.Id = t4.t3id
  GROUP BY t4.Name
) t;

Updated SQL Fiddle Demo

This will give you:

|       NAME |               PERCENTAGE |
-----------------------------------------
| Bob Marley | 60.00 AND 40.00 AND 0.00 |
| Tom Cruise | 100.00 AND 0.00 AND 0.00 |

You can add the WHERE clause to limit this values to only any user name like WHERE Name = 'Some name' in the outer query or in the subquery.

---

Update 2

OK, Sorry I missed that. There is no need to PIVOT or CONCAT() or dynamic SQL to do so. You can do this like so:

SELECT 
  t1.type,
  COUNT(t2.task) * 100 / 
  (SELECT COUNT(*)
   FROM T4 t 
   WHERE t4.Name = t.Name) AS Percentage
FROM T1
INNER JOIN T2 ON t1.ID = t2.T1ID
INNER JOIN t5 ON t2.task = t5.task
INNER JOIN t3 ON t3.id = t5.t3id
INNER JOIN t4 ON t3.Id = t4.t3id
WHERE t4.Name = 'Bob Marley' 
GROUP BY t4.Name, t1.type;

Updated SQL Fiddle Demo

This will give you:

|    TYPE | PERCENTAGE |
------------------------
| PROJECT |         60 |
| SUPPORT |         40 |