Ask a Question
  
  
  
Top Posters
Since Sunday
26
15
11
10
9
9
9
8
8
7
7
7
New Topic  
wrote...
Posts: 265
Rep: 0 0
A week ago
Briefly describe subqueries and joins. Explain when each is not an acceptable alternative for the other.
Source  Download Study Guide
Database Processing: Fundamentals, Design, and Implementation
Edition: 15th
Authors:
Read 17 times
1 Reply
Replies
Answer verified by a subject expert
wrote...
Posts: 190
A week ago
Sign in or Sign up in seconds to unlock everything on Biology Forums.
Subqueries and joins are both methods for retrieving data from multiple tables. Subqueries involve nesting one SELECT statement within another. The nested SELECT is used as part of a condition in the WHERE clause of the first SELECT statement. The nested SELECT statement can return a set of records from one table, which are then used in a logical operator within the parent SELECT query. A join combines records from each table into concatenated records containing the fields of both tables. The records are concatenated based on matching values in similar columns in the two tables. Subqueries cannot be used in situations where the results to be displayed include attributes from more than one table. Joins cannot be used as an alternative to a correlated subquery.
This verified answer contains over 120 words.
Related Topics
New Topic      
Explore
Post your homework questions and get free online help from our incredible volunteers.
Learn More
Improve Grades
Help Others
Save Time
Accessible 24/7
  70 People Browsing
 123 Signed Up Today
Related Images
 2032
 216
 100
Your Opinion
Who's your favorite biologist?
Votes: 14