内部联接和子查询的mysql限制

Question

I have the following query:

SELECT saturday_combinations.index, v.val AS  `row` , COUNT( * )  AS  `count` 
FROM saturday_combinations  
INNER JOIN (

SELECT ONE AS val
FROM saturday_combinations 
WHERE ONE IS NOT NULL 

UNION 
SELECT TWO AS val
FROM saturday_combinations
WHERE TWO IS NOT NULL 

UNION 
SELECT THREE AS val
FROM saturday_combinations
WHERE THREE IS NOT NULL 

UNION 
SELECT FOUR AS val
FROM saturday_combinations
WHERE FOUR IS NOT NULL 

UNION 
SELECT FIVE AS val
FROM saturday_combinations
WHERE FIVE IS NOT NULL


UNION 
SELECT SIX AS val
FROM saturday_combinations
WHERE SIX IS NOT NULL 

UNION 
SELECT SEVEN AS val
FROM saturday_combinations
WHERE SEVEN IS NOT NULL 

) v  ON v.val = saturday_combinations.ONE
  OR v.val = saturday_combinations.TWO
  OR v.val = saturday_combinations.THREE
  OR v.val = saturday_combinations.FOUR
  OR v.val = saturday_combinations.FIVE
  OR v.val = saturday_combinations.SIX
  OR v.val = saturday_combinations.SEVEN 
  GROUP BY v.val 

The purpose of the query is to provide a count of the different values contained in the columns ONE,TWO,THREE,FOUR,FIVE,SIX and SEVEN in the table saturday_combinations. However I want to put a desc limit 4 so that it only performs the count based on the last 4 rows (last four maximum indexes). But I am not getting it to work with the union. Adding order and limit at the very end only limits from the final select, rather than get the last 4 rows and calculate the distribution on them. Any tips?

The table schema is as follows:

index | ONE|TWO|THREE|FOUR|FIVE|SIX|SEVEN
 1       1   3   7     10    11  12  13
 2       3   4   5     30    31  22  23
 3       1   2   3      4     5   6   7
 4       1   2   3      4     5   6   7
 5       1   2   3      4     5   6   7
 6       1   2   3      4     5   6   7
 7       1   2   3      4     5   6   7
 8       1   2   3      4     5   6   7
 9       1   2   3      4     5   6   7
 10      1   2   3      4     5   6   7

Index is auto-increment and ONE-SEVEN has integer values.

There are about 3000 rows in the table and I want to count occurences for each value based on the last n rows.

Ideal result for the last n rows where n = last 3 rows should be
Numbers|Count
   1       3
   2       3
   3       3
   4       3
   5       3
   6       3
   7       3

If I increase n to include last 6 rows their count should increase. If I could last 10 rows the count should increase and other numbers should appear with their count.

Here is a link to a sample of the real table. http://sqlfiddle.com/#!2/d035b

Answer 1

If answer to my comment is yes then, you could try the following. When you need to add limit, order by to union selects you need to wrap union queries with brackets () .

• SQLFIDDLE DEMO

Code:

(SELECT ONE AS val
FROM saturday_combinations 
WHERE ONE IS NOT NULL 
order by ONE desc limit 4)

UNION 
(SELECT TWO AS val
FROM saturday_combinations
WHERE TWO IS NOT NULL 
order by TWO desc limit 4)

UNION 
(SELECT THREE AS val
FROM saturday_combinations
WHERE THREE IS NOT NULL 
order by THREE desc limit 4)

If answer to my comment is no , then please clarify.

Here is the code based on your sample date:

select distinct x.one as uniqunumbers,
count(x.one) as counts
from(
sELECT DISTINCT 'one' 
AS col1, one FROM sat_comb
UNION ALL
SELECT DISTINCT 'two' 
AS col1, two FROM sat_comb
UNION ALL
SELECT DISTINCT 'three' 
AS col1, three FROM sat_comb
) as x
group by x.one;

UNIQUNUMBERS    COUNTS
1               1
3               2
4               1
5               1
7               1

EDIT as per OP has clarified and updated the question.

Quoted: "However I want to limit it so that it first takes the last n rows and then does the count on the values in those n rows. This means, if I have 3 columns with 3000 rows and 35 integers randomly appearing in these 3000 rows it should count how many times each integer appears."

• SQLFIDDLE DEMO2

Query:

select x.one as uniqunumbers,
    count(x.one) as counts
    from(
    (sELECT DISTINCT 'one' 
    AS col1, one FROM sat_comb
     order by id desc limit 4)
    UNION ALL
    (SELECT DISTINCT 'two' 
    AS col1, two FROM sat_comb
     order by id desc limit 4)
    UNION ALL
    (SELECT DISTINCT 'three' 
    AS col1, three FROM sat_comb
     order by id desc limit 4)
      UNION ALL
    (SELECT DISTINCT 'four' 
    AS col1, four FROM sat_comb
     order by id desc limit 4)
      UNION ALL
    (SELECT DISTINCT 'five' 
    AS col1, five FROM sat_comb
     order by id desc limit 4)
      UNION ALL
    (SELECT DISTINCT 'six' 
    AS col1, six FROM sat_comb
     order by id desc limit 4)
      UNION ALL
    (SELECT DISTINCT 'seven' 
    AS col1, seven FROM sat_comb
     order by id desc limit 4)
    ) as x
    group by x.one;

Output:

UNIQUNUMBERS    COUNTS
2               4
3               3
4               3
5               4
6               4
8               3
9               4
20              3

Answer 2

Maybe I am missing something in your request but based on your desired result, why not just unpivot the data and perform the count.

select value, count(*) Total
from
(
  select 'one' col, one value
  from saturday_combinations
  union all
  select 'two' col, two value
  from saturday_combinations
  union all
  select 'three' col, three value
  from saturday_combinations
  union all
  select 'four' col, four value
  from saturday_combinations
  union all
  select 'five' col, five value
  from saturday_combinations
  union all
  select 'six' col, six value
  from saturday_combinations
  union all
  select 'seven' col, seven value
  from saturday_combinations
) src
group by value

See SQL Fiddle with Demo

The result of your sample is:

| VALUE | TOTAL |
-----------------
|     1 |     1 |
|     3 |     2 |
|     4 |     1 |
|     5 |     1 |
|     7 |     1 |
|    10 |     1 |
|    11 |     1 |
|    12 |     1 |
|    13 |     1 |
|    22 |     1 |
|    23 |     1 |
|    30 |     1 |
|    31 |     1 |

Edit #1: Based on your update this might be want you what:

select value, count(*)
from
(
  select col, value
  from
  (
    select 'one' col, one value
    from saturday_combinations
    order by one 
    limit 3
  ) one
  union all
  select col, value
  from
  (
    select 'two' col, two value
    from saturday_combinations
    order by two desc
    limit 3
  ) two
  union all
  select col, value
  from
  (
    select 'three' col, three value
    from saturday_combinations
    order by three 
    limit 3
  ) three
  union all
  select col, value
  from
  (
    select 'four' col, four value
    from saturday_combinations
    order by four 
    limit 3
  ) four
  union all
  select col, value
  from
  (
    select 'five' col, five value
    from saturday_combinations
    order by five 
    limit 3
  ) five
  union all
  select col, value
  from
  (
    select 'six' col, six value
    from saturday_combinations
    order by six 
    limit 3
  ) six
  union all
  select col, value
  from
  (
    select 'seven' col, seven value
    from saturday_combinations
    order by seven 
    limit 3
  ) seven
) src
group by value

See SQL Fiddle with Demo

Result:

| VALUE | COUNT(*) |
--------------------
|     1 |        3 |
|     2 |        1 |
|     3 |        4 |
|     4 |        4 |
|     5 |        3 |
|     6 |        3 |
|     7 |        3 |

Answer 3

如果您想查看最终解决方案： http ：//sqlfiddle.com/#！2/867a6/13感谢@bonCodigo的所有帮助