For the below tables, please write SQL queries:

Patient_Diagnosis
Field Name		Description		Data Type		Notes
Patient_ID		Patient Identifier		INTEGER
Diagnosis_Date		Date of Diagnosis		DATE		YYYY-MM-DD
Diagnosis_Code		Diagnosis Code		TEXT
Diagnosis		Internal Description		TEXT
Patient_Treatment
Field Name	Description		Data Type		Notes
Patient_ID	Patient Identifier		INTEGER
Treatment_Date	Date of Treament		DATE		YYYY-MM-DD
Drug_Code	Internal Drug Identifier		INTEGER

For the above tables, I am unable to arrive at a solution using SQL. Please help me with these SQL questions.

1. How long after being diagnosed does it take for a patient to start treatment? Do any patients start treatment before being diagnosed?
2. After being treated with a first line of treatment (a drug or combination of drugs), what proportion of all cancer patients go on to be treated with a second line of treatment?
3. How does each drug used at the clinic compare in terms of its duration of therapy?

The above is the sample dataset I was given.

Patient_Diagnosis.csv B A Patient_ID 2038 2120 2175 2010-01-21 2010-01-09 Diagnosis_Code Diagnosis 174.9 Breast Cancer 174.1 Breast Cancer 2010-02-17 174.7 Breast Cancer 2407 2010-06-13 174.9 Breast Cancer 174.9 Breast Cancer 2425 2010-12-15 2462 2011-01-07 174.9 Breast Cancer 2634 2011-02-19 153.9 Colon Cancer 2735 2011-04-18 174.9 Breast Cancer 2763 2011-04-19 174.1 Breast Cancer 2770 2011-04-16 3095 2011-07-10 2011-09-07 153.9 Colon Cancer 153.3 Colon Cancer 153.5 Colon Cancer 3449 3757 2011-10-11 153.4 Colon Cancer 2011-10-11 174.1 Breast Cancer 3757 3948 2011-12-18 174.6 Breast Cancer Patient_Treatment.csv A Patient_ID Treatment_Date Drug_Code 2010-02-14 201 2038 2038 2010-02-21 2038 2010-02-26 2038 2010-03-07 2010-03-14 2038 2038 2038 2038 2038 2010-03-21 2010-03-26 2010-04-04 2010-04-11 2038 2010-04-18 2010-04-25 2038 2038 2010-05-02 2038 201 2010-05-09 2010-05-16 2010-02-20 2010-02-27 2010-03-01 2010-03-08 2010-03-15 2010-03-22 2010-03-29 2010-04-05 2010-04-12 2010-04-19 2010-04-26 2038 2120 2120 2175 2175 2175 2175 2175 2175 2175 2175 2175 2175 2175 2175 2175 2175 2175 2175 2175 2175 2175 2407 2407 2010-05-03 2010-05-10 2010-05-17 2010-05-24 2010-05-31 2010-06-07 2010-06-14 2010-06-21 2010-06-28 2010-07-05 2010-07-28 2010-08-04