user: Question: What is the IATA code of the airport that has a Total Cargo of 1,838,894 Metric Tonnes?
Columns: ['Rank', 'Airport', 'Location', 'Code (IATA)', 'Total Cargo (Metric Tonnes)', '2003 Rank', '% Change']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Memphis International Airport', 'Memphis , Tennessee , United States', 'MEM', '3,554,575', '1', '+4.8%']
SQL:

assistant: SELECT "Code (IATA)" FROM "Table" WHERE "Total Cargo (Metric Tonnes)" = '1,838,894';