Task: Text to Code
Input (English): Step 1: find the number of rows of each value of Document_Type_Code in Ref_Document_Types table.
Step 2: find Document_Type_Code of Ref_Document_Types table with largest value in the results of step 1
Output (English): SELECT Document_Type_Code FROM Ref_Document_Types GROUP BY Document_Type_Code ORDER BY Count ( * ) Desc LIMIT 1