php - MySQL sorting by repetitive pattern -


i have list of products in mysql table this:

id_manufacturer | id_product 1                 1 2                 5 3                 6 4                 10 1                 14 2                 18 3                 25 4                 27 1                 28 2                 29 3                 30 4                 35 1                 40 2                 42 3                 45 4                 55

my desired outcome list of products ordered manufacturer grouped manufacturer 3 of each , repeat pattern again:

id_manufacturer | id_product 1                 1 1                 14 1                 28 2                 5 2                 29 2                 18 3                 6 3                 25 3                 30 4                 27 4                 35 4                 10 1                 154 1                 145 1                 285

can please?

thank you!

you can use nested queries local variables. try this:

select      id_manufacturer,      id_product (                 select                      id_manufacturer,                      id_product,                     case when (@prev_id <> id_manufacturer) (@num := 1) else (@num := @num + 1) end dummy1,                     (@prev_id := id_manufacturer) dummy2,                     @num rownum                 tbl, (select @prev_id := -1, @num := 0) x                 order                      id_manufacturer asc,                      id_product asc ) subq     rownum <= 3

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