多个表中的SQL sum和link字段

Question

Table 1

prodUID (*)    plantID   ItemName   size     qty
   1              1      car        med       5
   2              1      car        small     2
   3              1      car        large     8
   4              1      truck      small     7
   5              1      truck      med       0
   6              1      truck      large     4
   7              1      van        small     0
   8              2      truck      large    10

table2

UID(*)  plantID  table2_plan_tid  table2_prodUID  itemname  size     num    wk
------------------------------------------------------------------------------
  1        1          1              car                    med        3    41
  2        1          2              car                    small      0    42    
  3        1          3              car                    large      6    41
  4        1          4              truck                  small      1    44
  5        1          5              truck                  med       10    45    
  6        1          6              truck                  large      1    43
  7        1          7              van                    small      7    42
  8        2          8              car                    med       10    41

table3

UID(*)  plantid  table3_wk  table3_prodUID  itemName  size     qty
------------------------------------------------------------------
  1        1        41           2          car       med       5
  2        1        41           3          car       large     7
  3        1        43           7          van       small     8

Result I'm trying to get is

• for plantid = ? and wk between ? and ?

• plantid = 1 and wk between 41 and 45

• sum qty for table1 on plantID

• sum wk for table2 on plantID and for weeks
• sum qty on table with on plantID and for weeks

and some how link this with joins or subqueries to get

plantid  Itemname  qty   num   order
------------------------------------
   1     car        15    9     12
   1     truck      11   12      0
   1     van         0    7      8

I can't seem to get the right outcome

I also considered putting in an itemNameID field in all tables

if that would make it easier

Answer 1

You can achieve what you want using this query:

SELECT table1.plantID, table1.ItemName, SUM(table1.qty), COALESCE(t2.num_sum, 0), COALESCE(t3.qty_sum, 0)
FROM table1
LEFT JOIN (SELECT plantid, itemname, SUM(num) AS num_sum
      FROM table2
      WHERE wk >= 41 AND wk <= 45
      GROUP BY plantID, itemname) t2 ON table1.plantID = t2.plantID AND table1.ItemName = t2.ItemName
LEFT JOIN (SELECT plantid, itemname, SUM(qty) AS qty_sum
      FROM table3
      WHERE table3_wk >= 41 AND table3_wk <= 45
      GROUP BY plantID, itemname) t3 ON table1.plantID = t3.plantID AND table1.ItemName = t3.ItemName
WHERE table1.plantid = 1
GROUP BY plantID, ItemName

See also live!

Basically, you join 3 queries in order to get what you want. That would be a bit cleaner if you respect a certain harmony with you column names.