user: Question: When Middle Assyrian Empire is the ubaid period in mesopotamia what is the copper age?
Columns: ['Copper Age', 'Chalcolithic (4500 BC - 3300 BC)', 'Early Chalcolithic', '4500 BC - 4000 BC', 'Ubaid period in Mesopotamia']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Bronze Age (3300 BC - 1200 BC)', 'Early Bronze Age (3300 BC - 2000 BC)', 'Early Bronze Age I', '3300 BC - 3000 BC', 'Protodynastic to Early Dynastic Period of Egypt']
SQL:

assistant: SELECT "Copper Age" FROM "Table" WHERE "Ubaid period in Mesopotamia" = 'Middle Assyrian Empire';