A Guide to SQL
9th Edition
ISBN: 9781111527273
Author: Philip J. Pratt
Publisher: Course Technology Ptr
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Question
Chapter 4, Problem 16TD
Program Plan Intro
“SELECT” command:
The “SELECT” command is used to retrieve data in a
Syntax for selecting values from the table is as follows:
SELECT STUDENT_ID FROM STUDENT;
- The given query is used to display each student ID from “STUDENT” table.
Subquery:
- Subquery means one query is placed inside with another query.
- The inner query is called a subquery.
- The subquery is calculated first.
- After the subquery has been determined and the outer query can apply the results of the subquery.
Example:
The example for subquery is given below:
SELECT ORDER_NUMBER FROM ORDER_LINE WHERE BOOK_NUMBER IN(SELECT BOOK_NUMBER FROM BOOKS WHERE CATEGORY = 'CE');
The above query is used to list the order number using subquery.
- From the given query, the subquery is “(SELECT BOOK_NUMBER FROM BOOKS WHERE CATEGORY = 'CE')”.
- The subquery is computed first and then outer query is computed.
- The outer query retrieves the order number on every row in the “ORDER_LINE” table for which the book number is in the results of the subquery.
- Because that table contains only the book numbers in category “CE”, the results display the preferred list of order numbers.
- The outer query retrieves the order number on every row in the “ORDER_LINE” table for which the book number is in the results of the subquery.
“AVG” function:
- It is the one function of aggregate function.
- The “AVG” function is used to compute the average value in a column.
Example:
The example for “AVG” function is given below:
SELECT AVG(MARK_CREDIT) FROM STUDENT;
The above query is used to display the average of mark credit from “STUDENT” table using “AVG” function.
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List the item ID, description, and on-hand value of each item whose number of units on hand is more than the average number of units on hand for all items.
Use a subquery.
Chapter 4 Solutions
A Guide to SQL
Ch. 4 - Prob. 1RQCh. 4 - Prob. 2RQCh. 4 - Prob. 3RQCh. 4 - Prob. 4RQCh. 4 - Prob. 5RQCh. 4 - In which clause would you use a wildcard in a...Ch. 4 - Prob. 7RQCh. 4 - How do you determine whether a column contains one...Ch. 4 - Prob. 9RQCh. 4 - Prob. 10RQ
Ch. 4 - Prob. 11RQCh. 4 - Prob. 12RQCh. 4 - Prob. 13RQCh. 4 - Prob. 14RQCh. 4 - Prob. 15RQCh. 4 - Prob. 16RQCh. 4 - How do you find rows in which a particular column...Ch. 4 - Use the Internet to research the SQL [charlist]...Ch. 4 - Prob. 1TDCh. 4 - Prob. 2TDCh. 4 - Prob. 3TDCh. 4 - Prob. 4TDCh. 4 - Prob. 5TDCh. 4 - Prob. 6TDCh. 4 - Prob. 7TDCh. 4 - Prob. 8TDCh. 4 - Prob. 9TDCh. 4 - Prob. 10TDCh. 4 - Prob. 11TDCh. 4 - Prob. 12TDCh. 4 - Prob. 13TDCh. 4 - Prob. 14TDCh. 4 - Prob. 15TDCh. 4 - Prob. 16TDCh. 4 - What is the price of the least expensive item in...Ch. 4 - Prob. 18TDCh. 4 - Prob. 19TDCh. 4 - Prob. 20TDCh. 4 - Prob. 21TDCh. 4 - Prob. 22TDCh. 4 - Prob. 23TDCh. 4 - Prob. 1CATCh. 4 - Prob. 2CATCh. 4 - Prob. 3CATCh. 4 - Prob. 4CATCh. 4 - Prob. 5CATCh. 4 - Prob. 6CATCh. 4 - Prob. 7CATCh. 4 - Prob. 8CATCh. 4 - Prob. 9CATCh. 4 - Prob. 10CATCh. 4 - Prob. 11CATCh. 4 - Prob. 12CATCh. 4 - Prob. 13CATCh. 4 - Prob. 14CATCh. 4 - Prob. 15CATCh. 4 - Prob. 16CATCh. 4 - Prob. 17CATCh. 4 - Prob. 18CATCh. 4 - Prob. 19CATCh. 4 - List the reservation ID and trip ID for all trips...Ch. 4 - Prob. 1SCGCh. 4 - Prob. 2SCGCh. 4 - Prob. 3SCGCh. 4 - Prob. 4SCGCh. 4 - Prob. 5SCGCh. 4 - Prob. 6SCGCh. 4 - Prob. 7SCGCh. 4 - Prob. 8SCGCh. 4 - Prob. 9SCGCh. 4 - Prob. 10SCGCh. 4 - Prob. 11SCGCh. 4 - Prob. 12SCGCh. 4 - Prob. 13SCGCh. 4 - Prob. 14SCGCh. 4 - Prob. 15SCGCh. 4 - Prob. 16SCG
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ISBN:9781111527273
Author:Philip J. Pratt
Publisher:Course Technology Ptr