SQL选择行，其中多值字段的值仅出现一次

Question

I have the following problem:

I have a table with different columns describing objects. One of this column let's assume can contain the values 1,2,3,4,5,6,7,8,9,10. Within this table objects can contain all of these values or some just contain for example value 1,3,5 (so 0 to n values)

Now I want to find all the objects containing only the value 1 and 2, but I do not want them in my result set if they contain 1,2,3 or other combinations but (1,2).

How do I write this SQL statement?

Sample data (Result set to be expected --> Mark and Michael):

+---------+--------------------+---------------------------+--+
|   OBJ   | OBJ_CHARACTERISTIC | CHARACTERISTIC_DATE_ADDED |  |
+---------+--------------------+---------------------------+--+
| Mark    |                  1 |                15.01.2018 |  |
| Mark    |                  2 |                15.02.2018 |  |
| Jimmy   |                  1 |                31.01.2018 |  |
| Jimmy   |                  2 |                11.02.2018 |  |
| Jimmy   |                  4 |                15.03.2018 |  |
| Jimmy   |                  5 |                15.04.2018 |  |
| Jimmy   |                  6 |                15.04.2018 |  |
| Harry   |                  1 |                08.01.2018 |  |
| Harry   |                  2 |                11.01.2018 |  |
| Harry   |                  3 |                15.02.2018 |  |
| Michael |                  1 |                15.06.2018 |  |
| Michael |                  2 |                15.07.2018 |  |
| Dwayne  |                  4 |                15.01.2018 |  |
| Dwayne  |                  5 |                15.01.2018 |  |
| Dwayne  |                  6 |                15.01.2018 |  |
+---------+--------------------+---------------------------+--+

Answer 1

You could use analytic counts to see how many characteristics each object has, and how many of the ones you are looking for; and then compare those counts:

select obj, obj_characteristic, characteristic_date_added
from (
  select obj, obj_characteristic, characteristic_date_added,
    count(distinct obj_characteristic) over (partition by obj) as c1,
    count(distinct case when obj_characteristic in (1,2) then obj_characteristic end)
      over (partition by obj) as c2
  from your_table
)
where c1 = c2;

With your sample data that gives:

OBJ     OBJ_CHARACTERISTIC CHARACTERI
------- ------------------ ----------
Mark                     1 2018-01-15
Mark                     2 2018-02-15
Michael                  1 2018-06-15
Michael                  2 2018-07-15

From the way the question is worded it sounds like you want the complete rows, as above; froma comment you may only want the names. If so you can just change the outer select to:

select distinct obj
from ...

OBJ    
-------
Mark
Michael

or use aggregates instead via a having clause:

select obj
from your_table
group by obj
having count(distinct obj_characteristic)
  = count(distinct case when obj_characteristic in (1,2) then obj_characteristic end);

OBJ    
-------
Mark
Michael

db<>fiddle demo of all three .

---

In this case, as 1 and 2 are contiguous, you could also do this with min/max, as an aggregate to just get the names:

select obj
from your_table
group by obj
having min (obj_characteristic) = 1
and max(obj_characteristic) = 2;

or analytically to get the complete rows:

select obj, obj_characteristic, characteristic_date_added
from (
  select obj, obj_characteristic, characteristic_date_added,
    min(obj_characteristic) over (partition by obj) as min_char,
    max(obj_characteristic) over (partition by obj) as max_char
  from your_table
)
where min_char = 1
and max_char = 2;

but the earlier versions are more generic.

Answer 2

If you are just looking for sql to return rows values '1,2' and nothing else use:

select * from table where column like '%1,2'

Post an example of the data, it may be more helpful to understand.

Answer 3

@dwin90 You could try:

SELECT obj
FROM your_table
WHERE (OBJ_CHARACTERISTIC=1 OR OBJ_HARACTERISTIC=2 AND OBJ_CHARACTERISTIC !> 2
)GROUP BY OBJ