SQL Pivot 在 varchar 列上

Question

I have a result set that looks like this:

FlightCode  col2    Col3    SourceAirportCode
Flight007   NYC     SOURCE      64
Flight008   ORD     TARGET      87
Flight007   SEA     TARGET      NULL
Flight008   PHX     SOURCE      NULL

The end result I'm trying to achieve is this:

FlightCode  Source  Target  SourceAirportCode
Flight007   NYC     SEA     64
Fight008    PHX     ORD     87

Is this a pivot problem? I tried some pivoting but no luck or I just do not know enough about Pivot. Here is

SQL Fiddle Demo

with schema and insert statements. Please advise.

Answer 1

Assuming the flight codes actually match, then use conditional aggregation:

select flightcode,
       max(case when col3 = 'SOURCE' then col2 end) as source,
       max(case when col3 = 'TARGET' then col2 end) as target,
       max(SourceAirportCode) as SourceAirportCode
from t
group by flightcode;

Answer 2

You can use self join and consider one table as source and other table as Target.

WITH flight(FlightCode,  col2,    Col3,    SourceAirportCode)
AS 
(
 SELECT 'Flight007','NYC','SOURCE',64   UNION
 SELECT 'Flight008','ORD','TARGET',87   UNION
 SELECT 'Flight007','SEA','TARGET',NULL UNION
 SELECT 'Flight008','PHX','SOURCE',NULL
)

SELECT f.FlightCode, s.col2 as 'SOURCE', t.col2 as 'TARGET',
       f.SourceAirportCode
FROM flight f
JOIN flight s ON s.Col3 = 'SOURCE' AND s.FlightCode = f.FlightCode
JOIN flight t ON t.Col3 = 'TARGET' AND t.FlightCode = f.FlightCode
WHERE f.SourceAirportCode IS NOT NULL


FlightCode  SOURCE  TARGET  SourceAirportCode
 Flight007  NYC      SEA    64
 Flight008  PHX      ORD    87