1Z0-006 SQL Fundamentals & Data Manipulation 4

Question 1

Which SQL statement is used to permanently save changes made during a transaction?

Accepted Answer

COMMIT

Answer

COMMIT permanently writes all pending DML changes to the database, making them visible to other sessions.

Question 2

Which SQL function concatenates two strings in Oracle?

Accepted Answer

CONCAT(str1, str2) or str1 || str2

Answer

Oracle supports both the CONCAT function and the || pipe operator to join strings together.

Question 3

What does SELECT * FROM employees WHERE last_name LIKE '_a%'; return?

Accepted Answer

Rows where the second character of last_name is 'a'

Answer

The underscore (_) wildcard matches exactly one character, so _a% matches any name whose second character is 'a'.

Question 4

Which aggregate function returns the largest value in a column?

Accepted Answer

MAX(column)

Answer

MAX(column) is the standard SQL aggregate function that returns the highest value in a group.

Question 5

A subquery in a WHERE clause that returns exactly one value is called a:

Accepted Answer

Single-row subquery

Answer

A single-row subquery returns one row and one column, and is used with single-row comparison operators like =, >, <.

(1Z0-006) Oracle Database Foundations Associate Practice Test