SQL-根据2列和条件返回唯一行

Question

I have a table on HSQLDB with data as

Id   Account    Opendate    Baldate      LastName ........ State
1    1234       040111      041217       Jackson           AZ 
2    1234       040111      051217       James             FL 
3    2345       050112      061213       Thomas            CA
4    2345       050112      061213       Kay               DE

How can i write a query that gives me rows that have distinct values in Account and Opendate columns, having the maximum Baldate. If Baldate is also same, then return the first row ordered by Id.

So the resultset should contain

Id   Account    Opendate    Baldate      LastName........State
2    1234       040111      051217       James           FL
3    2345       050112      061213       Thomas          CA

I have gotten this far.

select LastName,...,State, max(BalDate) from ACCOUNTS group by Account, Opendate 

But the query fails since I cannot use an aggregate function for columns not in group by (lastname, state etc). How can I resolve this?

Answer 1

HSQLDB supports correlated subqueries, so I think this will work:

select a.*
from accounts a
where a.id = (select a2.id
              from accounts a2
              where a2.account = a.account and a2.opendate = a.opendate
              order by baldate desc, id asc
              limit 1
             );

Answer 2

I'm not familiar with hslqdb, so this is just ANSI. I see that it doesn't support analytical functions, which would make life easier.

If it works the other answer is a lot cleaner.

SELECT ACC_T1.Id,
       ACC_T1.Opendate,
       ACC_T1.Baldate
       ACC_T1.LastName,
       ...
       ACC_T1.State
  FROM Account_Table AS ACC_T1
 INNER
  JOIN (SELECT account,
               OpenDate,
               MAX(BalDate) AS m_BalDate
          FROM AccountTable
         GROUP
            BY account,
               OpenDate
       ) AS SB1
    ON ACC_T1.Account = SB1.Account
   AND ACC_T1.OpenDate = SB1.OpenDate
   AND ACC_T1.BalDate = SB1.m_BalDate
 INNER
  JOIN (SELECT account,
               OpenDate,
               BalDate,
               MIN(id) AS m_id
          FROM Account_Table
         GROUP
            BY account,
               OpenDate,
               BalDate
       ) AS SB2
    ON ACC_T1.Account = SB2.Account
   AND ACC_T1.OpenDate = SB2.OpenDate
   AND ACC_T1.BalDate = SB2.BalDate
   AND ACC_T1.id = SB2.m_id