mysql - Multiple interrelated loops in sql -


loop1 derived through easy logic. loop2 derived through complex logic. loop3 simple derived adding 2 loop2

now, want derive loop4 through combination of loop1, loop2 & loop3. problem loop2 heavy logic , query running slow if derive logic again inside loop3. provide more clarity, finding loop3 using loop1&2 , loop4 using loop1,2&3. please suggest way query work.

select sre.shipmentid,         loop1.try1,         loop2.try2,         loop3.try3,         (select case when u>0 loop1.try1 when u>1 loop2.try2 else loop3.try3 end) loop4 `shipmentrouteevent` sre left join (select sre1.shipmentid s1, (case when .....>0 .... end) ad try1            `shipmentrouteevent` sre1            sre1.updatedate='2013-07-01'           ) loop1 on sre.id=try1.id left join (select heavy logic modify try1 try2) loop2 left join (select (try2+2) try3) loop3 sre.updatedate='2013-07-01' 

i think want nested subqueries:

from (select . . .       fro (select . . .            `shipmentrouteevent` sre left join                  (select sre1.shipmentid s1, (case when .....>0 .... end) ad try1                   `shipmentrouteevent` sre1                   sre1.updatedate='2013-07-01'                 ) loop1                 on sre.id=try1.id            ) loop1 left join            (select heavy logic modify try1 try2            ) loop2            on . . .       ) loop2 left outer join       (. . .       ) loop3       on . . . 

each level of nesting allow use results @ next level, results not need recalculated.


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