sql server - Add a new column to a view in SQL -

this view

create view seat_availability select flightid,flightdate, maxcapacity, flight 

and want add 2 new columns named 'bookedseats' , 'availableseats' don't exist in tables columns need add.

i've done research online , can alter views using:

alter view  

and have said can't , have edit view you've created.

i've tried this:

create view seat_availability select flightid,flightdate, maxcapacity, bookedseats varchar(10), availableseats varchar(10) flight 

which gave error:

error: syntax error @ or near "varchar" line 2: ...ect flightid,flightdate, maxcapacity, bookedseats varchar(10...

i've tried alter view:

alter view seat_availability select flightid,flightdate, maxcapacity, bookedseats varchar(10), availableseats varchar(10) flight 

and got error:

error: syntax error @ or near "as" line 1: alter view seat_availability as

it easy add columns if existed in other tables because need add 2 columns don't exist in table, it's proving difficult do. if appreciated. thank you.

perhaps may need drop view? , start again 2 new columns added how add them since don't exist in table in database??

you don't define datatype of column that. let view use underlying datatype this.

alter view seat_availability select flightid     , flightdate     , maxcapacity     , bookedseats     , availableseats flight 

or if need explicitly change datatype need use convert this.

alter view seat_availability select flightid     , flightdate     , maxcapacity     , bookedseats = convert(varchar(10), bookedseats)     , availableseats = convert(varchar(10), availableseats) flight