Get Unlimited Contributor Access to the all ExamTopics Exams!
Take advantage of PDF Files for 1000+ Exams along with community discussions and pass IT Certification Exams Easily.
Given the following customer and order tables: Which of the following describes the number of rows and columns of data that would be present after performing an INNER JOIN of the tables?
A. Five rows, eight columns.
Inner join returns only the rows where there is a match between the two tables in the specified join condition. In this case, the join condition would be based on the "Customer ID" column, which is present in both tables. So, the inner join of the two tables would result in 5 rows where there is a match in the "Customer ID" column, and each row would have 8 columns (all columns from both tables).
B is the correct answer. There are 7 rows in the order table, all those 7 rows will retain when inner join occurred because Customer_ID matches the customer table. Since customer like 001 and 004 appear twice in the order table, they will appear twice in the newly joined table as well. There are 8 columns because Customer_ID column is in both tables, 4 unique columns in customer table, 3 unique columns in order table, combined is 8 columns. I tried it with SQL and it returned 7 rows, A is not the answer, joined table can have duplicates.
A voting comment increases the vote count for the chosen answer by one.
Upvoting a comment with a selected answer will also increase the vote count towards that answer by one.
So if you see a comment that you already agree with, you can upvote it instead of posting a new comment.
ronniehaang
Highly Voted 1 year, 3 months agoSwift_and_Quick
Most Recent 1 month agoHiromi_Nakatani
1 year, 3 months ago