mysql - SQL Switch even/odd values of the selection -
currently have selection 2 tables:
(select e.id, e.num, '1' tbl events e ) union (select p.id, p.num, '2' tbl places p ) order 2 desc
it returns values ordered num
this:
id | num | tbl 3 | 9 | 2 1 | 8 | 2 4 | 7 | 1 1 | 4 | 1 7 | 1 | 2
but goal mix tables in selection not losing order
within specific table. this:
id | num | tbl 3 | 9 | 2 4 | 7 | 1 1 | 8 | 2 1 | 4 | 1 7 | 1 | 2
thanks in advance! appreciate help!
if want interleave tables, need additional information. if enumerate each row, can use sorting. this:
(select e.id, e.num, '1' tbl, (@rn1 := @rn1 + 1) rn events e cross join (select @rn1 := 0) vars order e.num desc ) union (select p.id, p.num, '2' tbl, (@rn2 := @rn2 + 1) rn places p cross join (select @rn2 := 0) vars order p.num desc ) order rn, tbl desc;
Comments
Post a Comment