sql - Interesting Query in MySQL with conditions -
here question:
management wants know specific aircraft have been assigned same hangar lot (each aircraft assigned lot year , renewed if requested. lot may or may not same lot upon renewal; pk lots table registration number , date assigned. list aircraft registration number, hangar location, hangar capacity. each aircraft should appear once in report.
here lots table:
lot_nbr, hangar_nbr, reg_nbr, date_assigned
'7706', '1', '505', '2011-07-17'
'7707', '1', '505', '2012-07-18'
'7708', '1', '505', '2013-12-22'
'8801', '2', '101', '2011-01-22'
'8802', '2', '101', '2012-01-22'
'8803', '2', '303', '2011-01-10'
'8803', '2', '202', '2011-04-12'
'8803', '2', '202', '2012-04-12'
'9902', '3', '303', '2012-01-10'
'9904', '3', '404', '2011-01-10'
'9905', '3', '404', '2012-01-10'
here hangar table:
hangar_nbr, location, capacity, manager_nbr
'1', 'south rw', '24', '902'
'2', 'north rw', '12', '902'
'3', 'west rw', '25', '902'
here aircraft table: (might needed)
reg_nbr, plane_type, manufacturer, resident, date_service
'101', 'se', 'prop', 'lear', '1', '1998-12-01'
'202', 'de prop', 'cessna', '1','1999-11-22'
'303', 'se jet', 'bombardier', '1', '2000-07-06'
'404','me jet', 'lear', '1', '2001-02-24'
'505', 'se prop', 'cessna', '0','2003-12-01'
'606', 'de prop', 'bombardier', '1', '2004-11-22'
'707','se jet', 'lear', '1', '2005-07-06'
'808', 'me jet', 'cessna', '0','2005-02-24'
'909', 'se prop', 'bombardier', '1', '2002-02-12'
the query want (exactly):
reg_nbr, location, capacity
'202', 'north rw', '12'
here tried:
select lots.reg_nbr, location, capacity hangar, lots lots.hangar_nbr = hangar.hangar_nbr , reg_nbr='202' group lots.reg_nbr
my problem:
as shown above wanted show aircraft reg_nbr '202'
in result because aircraft has been allocated same lot_nbr every time unfortunately way did i.e writing reg_nbr ='202'
in clause not way query should done. want show how results real , legal query. lot effort.
select reg_nbr lots group reg_nbr having count(distinct lot_nbr) = 1
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