dbpath = /etc/postfix/private/mail.sqlite
query = SELECT coalesce(T1.tpTransport, '') || ':' ||
	(CASE WHEN tpMx=0
		THEN '[' || coalesce(T1.tpNexthop, '') || ']'
		ELSE coalesce(T1.tpNexthop, '')
	END) ||
	(CASE WHEN tpPort IS NOT NULL
		THEN ':' || tpPort
		ELSE ''
	END)
	FROM Transport AS T1
	WHERE T1.active!=0
	AND T1.tpNum=
		coalesce((SELECT coalesce(A2.addTpNum, D2.domTpNum)
		FROM Address AS A2
		JOIN Domain AS D2 ON A2.addDomNum=D2.domNum
		WHERE A2.addLocalpart || '@' || D2.domName IS '%s'
		AND A2.active!=0),
		(SELECT D1.domTpNum FROM Domain AS D1
		WHERE D1.domName IS '%s' AND D1.active!=0))

# Postfix transport(5) lookups
#	Case 1: queries for user-exten@domain
#	Case 2: queries for user@domain
#	Case 3: queries for domain (%u is suppressed)
#	Case 4: queries for .domain (%u is suppressed)
#	Case 5: queries for wildcard "*" (%u is suppressed)
# This query will match any listed address without ever going to
# Case 3. If there is an extension, it won't match unless
# user-exten@domain is in the Addresses table.
#
# Matched domains without any address listings will be matched in
# case 3 or 4. We don't have a wildcard in the sample data, but
# there's no reason why it wouldn't work too.
#
# Unmatched domains will be searched through all cases.