SQL Exercise: Medical procedures done after certification expired

SQL hospital Database: Exercise-34 with Solution

34. From the following table, write a SQL query to find all physicians who have completed medical procedures with certification after their certificates expired. Return Physician Name as "Physician", Position as" Position", Procedure Name as "Procedure", Date of Procedure as "Date of Procedure", Patient Name as "Patient", and expiry date of certification as "Expiry Date of Certificate".

Sample table: physician

Sample table: undergoes

Sample table: patient

Sample table: procedure

Sample table: trained_in

Sample Solution:

SELECT p.name AS "Physician",
       p.position AS "Position",
       pr.name AS "Procedure",
       u.date AS "Date of Procedure",
       pt.name AS "Patient",
       t.certificationexpires AS "Expiry Date of Certificate"
FROM physician p,
     undergoes u,
     patient pt,
     PROCEDURE pr,
               trained_in t
WHERE u.patient = pt.ssn
  AND u.procedure = pr.code
  AND u.physician = p.employeeid
  AND Pr.code = t.treatment
  AND P.employeeid = t.physician
  AND u.Date > t.certificationexpires;

Sample Output:

  Physician   |           Position           |         Procedure          |  Date of Procedure  |  Patient   | Expiry Date of Certificate
--------------+------------------------------+----------------------------+---------------------+------------+-------------------------
 Todd Quinlan | Surgical Attending Physician | Obfuscated Dermogastrotomy | 2008-05-09 00:00:00 | Dennis Doe | 2007-12-31
(1 row) 

Explanation:

The said query in SQL that selects the physician's name and position, the name of the procedure, the date of the procedure, the patient's name, and the expiry date of the physician's certificate for the procedure from the tables 'undergoes', 'patient', 'procedure', 'trained_in' and 'physician'.

The query joins the tables 'undergoes' and 'patient' based on the columns patient and ssn, the tables 'undergoes' and 'procedure' based on the columns procedure and code, the tables 'procedure' and 'trained_in' based on the columns code and treatment, and the tables 'physician' and 'trained_in' based on the columns employeeid and physician.

The WHERE clause at the end of the query filters the results to only include procedures performed after the physician's certification has expired.

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E R Diagram of Hospital Database:

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