user: Question: What is the abbreviation of the district of Mahbubnagar?
Columns: ['Code', 'District', 'Headquarters', 'Population (2011)', 'Area (km²)', 'Density (/km²)', 'Official website']
Types: ['text', 'text', 'text', 'real', 'real', 'real', 'text']
Sample row: ['AD', 'Adilabad', 'Adilabad', 2737738.0, 16105.0, 170.0, 'http://adilabad.nic.in/']
SQL:

assistant: SELECT "Code" FROM "Table" WHERE "District" = 'Mahbubnagar';