仅当所有相关记录匹配时才选择记录

Question

Again I am stuck with a query. I want to select all records from table1 in which ALL related table2 records satisfy a condition. Only when the ALL table 2 records satisfy it.

I tried this. But it's not working.

select m.* from table1 m
 inner join table2 I on m.Id = I.Id
where 
I.Id = ALL (select t.Id from table2 t where t.Id = I.Id and t.Status = 3)

Answer 1

If you want the rows from m where all statuses are 3 in I , then use not exists :

select m.* 
from table1 m
where not exists (select 1
                  from table2 I 
                  where I.Id = m.Id and I.status <> 3
                 );

EDIT:

Note that this matches rows where there are no matches in table2 . That technically meets the requirement that all rows have a status of 3 . But if you want to require a row, you can add an exists condition:

select m.* 
from table1 m
where not exists (select 1
                  from table2 I 
                  where I.Id = m.Id and I.status <> 3
                 ) and
      exists (select 1
              from table2 I 
              where I.Id = m.Id and I.status = 3
             );

Both of these can take advantage of an index on table2(Id, status) . Methods that use some form of aggregation require additional work and should be a little less performant on large data sets (particularly when there are many matches in table2 ).

Answer 2

You could drop the join to table2 and change the all to in or exists. or you could add t.status = 3 to the on clause and get rid of the where clause.

Answer 3

You can add NOT EXISTS to the ON clause:

select m.* 
from table1 m inner join table2 I 
on m.Id = I.Id 
and not exists (select t.Id from table2 t where t.Id = m.Id and t.Status <> 3)

This way you select from table1 all the rows that are related to table2 and the related rows all satisfy the condition that Status = 3 .
Or, without a join , use in the WHERE clause a subquery that returns all the Id s of table2 that satisfy the condition Status = 3 :

select * 
from table1  
where Id in (
  select Id from table2
  group by Id
  having min(Status) = 3 and max(Status) = 3
)