CREATE TABLE Templates (template_type_code VARCHAR(255), template_id VARCHAR(255)); CREATE TABLE Documents (template_id VARCHAR(255), document_name VARCHAR(255))
What is the template type code of the template used by document with the name "Data base"?
    
SQL: SELECT T1.template_type_code FROM Templates AS T1 JOIN Documents AS T2 ON T1.template_id = T2.template_id WHERE T2.document_name = "Data base"