Back-End Development Development Technical (SQL) 4

Question 1

What does DDL stand for in the context of SQL?

Accepted Answer

Data Definition Language

Answer

DDL (Data Definition Language) includes statements like CREATE, ALTER, DROP, and TRUNCATE that define or modify database schema structure.

Question 2

Which SQL JOIN type returns only rows where there is a match in BOTH tables?

Accepted Answer

INNER JOIN

Answer

INNER JOIN returns only the rows for which the join condition is satisfied in both tables, excluding non-matching rows from either side.

Question 3

What problem does database normalization primarily aim to solve?

Accepted Answer

Data redundancy and update anomalies

Answer

Normalization organizes data to reduce redundancy and prevent insert, update, and delete anomalies by ensuring each fact is stored once.

Question 4

Which SQL function converts a string to uppercase?

Accepted Answer

UPPER()

Answer

UPPER() is the standard SQL function that converts all characters in a string to their uppercase equivalents.

Question 5

What is a SQL VIEW?

Accepted Answer

A named stored query that can be used like a table

Answer

A VIEW is a saved SQL query given a name; when queried, the database executes the underlying SELECT and returns results as if from a table.

Back-End Development Practice Test