Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_28 ( prothrombin_time VARCHAR, partial_thromboplastin_time VARCHAR, platelet_count VARCHAR, bleeding_time VARCHAR )

### Question ###
Which Prothrombin time has a Platelet count of unaffected, and a Bleeding time of unaffected, and a Partial thromboplastin time of normal or mildly prolonged?

### Accurate SQL ###

SELECT prothrombin_time FROM table_name_28 WHERE platelet_count = "unaffected" AND bleeding_time = "unaffected" AND partial_thromboplastin_time = "normal or mildly prolonged"