[Solved] SQL querying – Doctors and Hospitals [closed]

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Introduction

SQL querying is a powerful tool for managing data in a database. It is used to retrieve, manipulate, and store data in a database. In this article, we will discuss how to use SQL querying to manage data related to doctors and hospitals. We will look at how to query data related to doctors, such as their names, specialties, and contact information, as well as data related to hospitals, such as their locations, services, and patient reviews. We will also discuss how to use SQL querying to create reports and analyze data. Finally, we will discuss how to use SQL querying to optimize performance and ensure data integrity.

Solution

SELECT d.name AS ‘Doctor Name’, h.name AS ‘Hospital Name’
FROM doctors d
INNER JOIN hospitals h
ON d.hospital_id = h.id;


I’ll help you with your first question, and I’ll leave to you the second.

  1. Display doctorid, dname, total fees received by the doctor(s) who have treated more than one patient?

Let’s split this problem in pieces:

So you need first to know which doctors have treated more than one patient. That information is in the table billing. So:

select doctorId, count(patientId) as patientCount
from (select distinct doctorId, patientId from billing) as a
group by doctorId
having count(patientId)>1;

This query will return only the Ids of the doctors that have more than one patient. Notice that I’m using a subquery to deduplicate the doctor-patient tuple.

Now let’s attack the other part of this question: The total fees of each doctor. Again, that info is in the table billing:

select doctorId, sum(fees) as totalFees
from billing
group by doctorId;

Finally, let’s put it all together, and include the doctor’s info, which is in the table doctor:

select
    d.doctorId, d.doctorName, a.totalFees
from
    doctor as d
    inner join (
        select doctorId, sum(fees) as totalFees
        from billing
        group by doctorId
    ) as a on d.doctorId = a.doctorId
    inner join (
        select doctorId, count(patientId) as patientCount
        from (select distinct doctorId, patientId from billing) as a
        group by doctorId
        having count(patientId)>1;
    ) as b on d.doctorId = b.doctorId;

Hope this helps

Things you need to study and (or) keep in mind:

  1. You need to understand how to relate data stored in different tables. Study how to use INNER JOIN (and also LEFT JOIN and RIGHT JOIN)
  2. You need to understand how does GROUP BY works, and how to use aggregate functions (sum(), count(), etcetera).
  3. You know how to write subqueries. Now try to use them not only for where conditions, but as data sources (including them in from statements)
  4. Keep a copy of the reference manual of your RDBMS at hand. Also a good book on SQL can help you (go to a bookstore or library and find one you like).

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solved SQL querying – Doctors and Hospitals [closed]


Solved SQL Querying – Doctors and Hospitals

SQL is a powerful language used to query databases. It can be used to retrieve information from a database, such as doctors and hospitals. In this article, we will discuss how to use SQL to query a database for doctors and hospitals.

Retrieving Doctors

The first step in retrieving doctors from a database is to create a query. The query should include the table name, the columns to be retrieved, and any conditions that need to be met. For example, if we wanted to retrieve all doctors from a database, the query would look like this:

SELECT * FROM doctors;

This query will return all the columns from the doctors table. If we wanted to retrieve only certain columns, we could specify them in the query. For example, if we wanted to retrieve only the doctor’s name and specialty, the query would look like this:

SELECT name, specialty FROM doctors;

We can also add conditions to the query to filter the results. For example, if we wanted to retrieve only doctors who specialize in pediatrics, the query would look like this:

SELECT * FROM doctors WHERE specialty = 'pediatrics';

Retrieving Hospitals

The process for retrieving hospitals from a database is similar to retrieving doctors. The query should include the table name, the columns to be retrieved, and any conditions that need to be met. For example, if we wanted to retrieve all hospitals from a database, the query would look like this:

SELECT * FROM hospitals;

This query will return all the columns from the hospitals table. If we wanted to retrieve only certain columns, we could specify them in the query. For example, if we wanted to retrieve only the hospital’s name and address, the query would look like this:

SELECT name, address FROM hospitals;

We can also add conditions to the query to filter the results. For example, if we wanted to retrieve only hospitals in a certain city, the query would look like this:

SELECT * FROM hospitals WHERE city = 'New York';

Conclusion

SQL is a powerful language used to query databases. It can be used to retrieve information from a database, such as doctors and hospitals. By using the correct query syntax, we can easily retrieve the information we need from a database.