CREATE TABLE Students ( student_id int, ); student_name varchar (50) NOT NULL, gender char (1) NULL, age float NULL, ); EMail varchar(40) NULL, EntryDate date NULL CREATE TABLE Professors ( prof_id int, prof_name varchar (50) NOT NULL dept varchar(5) NULL, officephone varchar(16) NULL EMail varchar(40) NULL webAddress varchar(40) NULL I I I
SQL
SQL stands for Structured Query Language, is a form of communication that uses queries structured in a specific format to store, manage & retrieve data from a relational database.
Queries
A query is a type of computer programming language that is used to retrieve data from a database. Databases are useful in a variety of ways. They enable the retrieval of records or parts of records, as well as the performance of various calculations prior to displaying the results. A search query is one type of query that many people perform several times per day. A search query is executed every time you use a search engine to find something. When you press the Enter key, the keywords are sent to the search engine, where they are processed by an algorithm that retrieves related results from the search index. Your query's results are displayed on a search engine results page, or SER.
help with sql class
Report the names of the professors who work on the most number of projects
The SQL code is as following
-- select columns p.prof_name, s.student_name with distinct keyword to get unique values
select distinct p.prof_name, s.student_name
from Supervise as sp -- from Supervise table with an alias name sp
inner join Professors as p -- inner join Professors to Supervise with an alias name p
on sp.prof_id = p.prof_id -- on condition to join both the tables
inner join Students as s -- inner join Students to Professors with an alias name s
on sp.student_id = s.student_id -- on condition to join both the tables
union -- union operator to combine left and right queries
select p.prof_name, concat('Total ', COUNT(distinct sp.student_id)) -- select columns p.prof_name, concat('Total ', COUNT(distinct sp.student_id))
from Supervise as sp -- from Supervise table with an alias name sp
inner join Professors as p -- inner join Professors to Supervise with an alias name p
on sp.prof_id = p.prof_id -- on condition to join both the tables
group by p.prof_id, p.prof_name -- group by to aggregate per professor
order by prof_name; -- order by to sort the results by professor name
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