In Example 8.17 consider the query SELECT Patient_ID#, Name FROM S WHERE Primary_
Diagnosis The response to the query is the projection onto the first two coordinates of the intersection of the database with the set
Find the result of the query SELECT Patient_ID#, NameFROM S WHERE Primary_Diagnosis = pneumonia.
The result of the query SELECTPatient-ID#, Name FROM S WHERE Primary-Diagnosis= X is the projection onto the first two coordinates ofthe intersection of the set with thedatabase.
The relation R contains the following 4-tuples:
(011985, John Schmidt, 02071, asthma)
(574329, Tak kurosawa, 0114910, pneumonia)
(466581, Mary Lazars, 0103910, appendicitis)
(008352, Joan Kaplan, 112409, gastritis)
(011985, John Schmidt, 021710, pneumonia)
(244388, Sarah Wu, 010310, broken leg)
(778400, Jamal Baskers, 122709, appendicitis)
Name FROM S WHERE
The query then requests all 4-tuples in the relation R that contains “pneumonia” as the 4th
Find the result of the query SELECT Patient_ID#, NameFROM S WHERE Primary_Diagnosis = appendicitis.
Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!Get Started