user: Question: What is Stop No., when Destination is Perth, and when Line is Midland?
Columns: ['Stop no.', 'Platform', 'Line', 'Stopping pattern', 'Destination']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['[2778] Claisebrook Station platforms', '[2778] Claisebrook Station platforms', '[2778] Claisebrook Station platforms', '[2778] Claisebrook Station platforms', '[2778] Claisebrook Station platforms']
SQL:

assistant: SELECT "Stop no." FROM "Table" WHERE "Destination" = 'Perth' AND "Line" = 'Midland';