mysql - Sorting result with absolute placement -


http://sqlfiddle.com/#!2/1840d/1

i have table of ids , places, possible rows set @ specified places?

to get

id  place 5   (null) 3   2 4   (null) 6   4 2   (null) 1   (null)

instead of

id  place 6   4 5   (null) 4   (null) 3   2 2   (null) 1   (null)

for data means have row place = 2 second row in result , row place = 4 fourth in result, while other rows cover them in original order.

answer 

select * records  order field(id, 5,3,4,6,2,1)

is nice , funny, wrong.

select case when nullid null         id        else nullid        end id,         tofilltable.place  (     select case when id null             @placeholder := @placeholder + 1             else null             end placeholder          , r.*         (         select @row := @row + 1 row         records t1, (select @row := 0) t2     ) s         inner join (select @placeholder := 0) t12         left outer join records r             on s.row = r.place     order row ) tofilltable     left outer join     (           select @row1 := @row1 + 1 nullrowplace, t1.id nullid           records t1, (select @row1 := 0) t2           place null           order t1.id desc     ) nullplacetable on tofilltable.placeholder = nullplacetable.nullrowplace

the first query output result :

tofilltable  placeholder    id    place     1        (null)  (null)   (null)       3       2     2        (null)  (null)   (null)       6       4     3        (null)  (null)     4        (null)  (null)

it gives id when place given on right row, , give counter named placeholder on row place null.

the second query:

nullplacetable   nullplaceholder    idnull      1                5      2                4      3                2      4                1

it gives rank of row when place null.

the join of 2 gives expected!

fiddle.

reference:


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