SQL从不同的表中选择计数和总和

Question

I need help to resolve this. I have 4 tables :

Transactions

| id | cid | gt |   rt |

|  1 |  6  | 2  |  5   |
|  2 |  6  | 9  |  7.5 |
|  3 |  6  | 3  |  9.7 |
|  4 |  3  | 3  |  7.0 |
|  5 |  3  | 7  |  6.8 |
|  6 |  9  | 4  |  2.5 |
|  7 |  9  | 2  |  5.4 |

Clients

| id | firstname | lastname | date |

|  1 |  jean     | moulin   | 1987 | 
|  2 |  salah    | fera     | 1968
|  3 |  marouan  | youra    | 2001 |
|  4 |  amin     | esa      | 1963 |
|  5 |  kamal    | tara     | 1789 |
|  6 |  moad     | mara     | 2005 |
|  9 |  safaa    | dara     | 2004 |

Produit A

| id | cid | 

|  1 |  6  | 
|  2 |  6  | 
|  3 |  3  | 
|  4 |  3  | 
|  5 |  3  |
|  6 |  4  | 
|  7 |  1  | 

Produit B

| id | cid |

|  1 |  6  | 
|  2 |  3  | 
|  3 |  9  | 
|  4 |  3  | 
|  5 |  3  | 
|  6 |  4  | 
|  7 |  6  | 

The result that i need is :

cid |  name |  date  |  pa | pb | gt | rt | 
3   |       |        |     |    |    |    |
6   |       |        |     |    |    |    |
9   |       |        |     |    |    |    |

I need to select from transaction all distinct client id (pid) and select the firstname and last name (name = firstname lastname) and date from clients table and sum all values (gt) and (rt) and search in table produitA the number of products for this client by his id and the same thing for the table produitB.

What i do for this but it don't work is (suggested by Gimeniux):

SELECT 
clients.id, 
CONCAT(firstname, ' ', lastname) as name,
date, 
count(distinct produitA.id) as pa, 
count(distinct produitB.id) as pb, 
sum(gt) AS gt, 
sum(rt) AS rt 

FROM clients
LEFT JOIN transactions ON clients.id = transactions.pid
LEFT JOIN produitA ON clients.id  = produitA.cid
LEFT JOIN produitB ON clients.id = produitB.cid

where pid is not null
group by clients.id

The probleme here is that gt and rt values are true for only the first client. For the second client and third and ... there is different values that are not true.

Answer 1

Although is hard for me to see the logic between your tables, you can use this query to get the result you desire. But i think it won't work if there are two same 'gt' or two same 'rt' values for one client.

SELECT 
clients.id, 
CONCAT(firstname, ' ', lastname) as name,
date, 
count(distinct produitA.id) as pa, 
count(distinct produitB.id) as pb, 
sum(distinct gt) AS gt, 
sum(distinct rt) AS rt 

FROM clients
LEFT JOIN transactions ON clients.id = transactions.pid
LEFT JOIN produitA ON clients.id  = produitA.cid
LEFT JOIN produitB ON clients.id = produitB.cid

where pid is not null

group by clients.id

Row for pid=9 doesn't show because in the data you gave there is no client with id=9