Question

I have SQL Query, I want to add insert blank row in result so it is easy to see the result.
I want to insert it after ORDER BY. don’t know if it could be done.

Here is my select statement.

SELECT TableName.CREWACTIONFACTID
      ,TableName.CREWKEY as CrewKey
      ,TableName.EVENTKEY as EventID
      ,TableName.ACTIONSEQUENCE
      ,case TableName.ACTIONTYPE
            when 'DISPATCHED' then '2-Dispatched'
            when 'ASSIGNED' then '1-Assigned'
            when 'ENROUTE' then '3-Entoute'
            when 'ARRIVED' then '4-Arrived'
            else 'unknown'
            end  as Type
      ,TableName.STARTDATETIME as StartTime
      ,TableName.ENDDATETIME as EndTIme
      ,TableName.DURATION as Duration

  FROM DatabaseName.TableName TableName
  where 
    To_Date(to_char(TableName.STARTDATETIME, 'DD-MON-YYYY')) >= To_Date('?DATE1::?','MM/DD/YYYY')
    AND To_Date(to_char(TableName.ENDDATETIME, 'DD-MON-YYYY')) <= To_Date('?DATE2::?','MM/DD/YYYY')
   ORDER BY TableName.EVENTKEY, TableName.STARTDATETIME,TableName.ACTIONSEQUENCE

Answer 1

You can, pretty much as Michael and Gordon did, just tack an empty row on with union all, but you need to have it before the order by:

...
and to_date(to_char(t.enddatetime, 'DD-MON-YYYY')) <=
    to_date('?DATE2::?','MM/DD/YYYY')
union all
select null, null, null, null, null, null, null, null
from dual
order by eventid, starttime, actionsequence;

… and you can’t use the case that Gordon had directly in the order by because it isn’t a selected value – you’ll get an ORA-07185. (Note that the column names in the order by are the aliases that you assigned in the select, not those in the table; and you don’t include the table name/alias; and it isn’t necessary to alias the null columns in the union part, but you may want to for clarity).

But this relies on null being sorted after any real values, which may not always be the case (not sure, but might be affected by NLS parameters), and it isn’t known if the real eventkey can ever be null anyway. So it’s probably safer to introduce a dummy column in both parts of the query and use that for the ordering, but exclude it from the results by nesting the query:

select crewactionfactid, crewkey, eventid, actionsequence, type,
    starttime, endtime, duration
from (
    select 0 as dummy_order_field,
        t.crewactionfactid,
        t.crewkey,
        t.eventkey as eventid,
        t.actionsequence,
        case t.actiontype
            when 'DISPATCHED' then '2-Dispatched'
            when 'ASSIGNED' then '1-Assigned'
            when 'ENROUTE' then '3-Enroute'
            when 'ARRIVED' then '4-Arrived'
            else 'unknown'
        end as type,
        t.startdatetime as starttime,
        t.enddatetime as endtime,
        t.duration
    from schema_name.table_name t
    where to_date(to_char(t.startdatetime, 'DD-MON-YYYY')) >=
        to_date('?DATE1::?','MM/DD/YYYY')
    and to_date(to_char(t.enddatetime, 'DD-MON-YYYY')) <=
        to_date('?DATE2::?','MM/DD/YYYY')
    union all
    select 1, null, null, null, null, null, null, null, null
    from dual
)
order by dummy_order_field, eventid, starttime, action sequence;

The date handling is odd though, particularly the to_date(to_char(...)) parts. It looks like you’re just trying to lose the time portion, in which case you can use trunk instead:

where trunc(t.startdatetime) >= to_date('?DATE1::?','MM/DD/YYYY')
and trunc(t.enddatetime) <= to_date('?DATE2::?','MM/DD/YYYY')

But applying any function to the date column prevents any index on it being used, so it’s better to leave that alone and get the variable part in the right state for comparison:

where t.startdatetime >= to_date('?DATE1::?','MM/DD/YYYY')
and t.enddatetime < to_date('?DATE2::?','MM/DD/YYYY') + 1

The + 1 adds a day, so id DATE2 was 07/12/2012, the filter is < 2012-07-13 00:00:00, which is the same as <= 2012-07-12 23:59:59.