複数のクエリの結果を交互に並べ替える方法は？

これがあなたがこれを行う方法です

select @rn:[email protected]+1 as id,colors from (
  (select @rn1:= @rn1+1 as rn,colors from table1,(select @rn1:=0)x order by id )
   union all 
  (select @rn2:= @rn2+1 as rn,numbers as colors from table2,(select @rn2:=0.5)x order by id)
   union all 
  (select @rn3:= @rn3+1 as rn,names as colors from table3,(select @rn3:=0.6)x order by id )
)x,(select @rn:=0)y order by rn ;

アイデアは、rnを割り当てることです 各テーブルアイテムの値であり、これらの値が常に昇順であることを確認する必要があります

したがって、テーブルごとにクエリを実行すると、次のようになります

mysql> select @rn1:= @rn1+1 as rn,colors from table1,(select @rn1:=0)x order by id;
+------+--------+
| rn   | colors |
+------+--------+
|    1 | red    |
|    2 | green  |
|    3 | blue   |
|    4 | yellow |
+------+--------+
4 rows in set (0.00 sec)

mysql> select @rn2:= @rn2+1 as rn,numbers as colors from table2,(select @rn2:=0.5)x order by id;
+------+--------+
| rn   | colors |
+------+--------+
|  1.5 | ten    |
|  2.5 | two    |
|  3.5 | one    |
|  4.5 | three  |
|  5.5 | six    |
|  6.5 | five   |
+------+--------+
6 rows in set (0.00 sec)

mysql> select @rn3:= @rn3+1 as rn,names as colors from table3,(select @rn3:=0.6)x order by id;
+------+--------+
| rn   | colors |
+------+--------+
|  1.6 | jack   |
|  2.6 | peter  |
+------+--------+
2 rows in set (0.00 sec)

ここでtable1 rnを見ることができます 値は1,2,3,.... table2 値は1.5,2.5,3.5,.... table3 値は1.6,2.6,....

したがって、最終的にすべてのrnで結果を注文すると、次のようになります

1,1.5,1.6,2,2.5,2.6,....