SQL FUNDAMENDALS

Remember: What does SQL stand for?

• Structured Query Language
• Style Query Language
• System Query Language
• Simplified Query Language

Remember: Which statement is used to create a table in SQL?

• CREATE
• ALTER
• DELETE
• SELECT

Remember: Which statement is used to delete a table in SQL?

• DROP
• DELETE
• REMOVE
• TRUNCATE

Understand: What is the difference between the DROP and TRUNCATE statements?

• DROP deletes the table and its structure, while TRUNCATE only deletes the table data.
• DROP deletes the table data, while TRUNCATE deletes the table and its structure.
• DROP and TRUNCATE are the same.
• DROP and TRUNCATE are used to delete columns from a table.

Understand: What is the difference between the WHERE and HAVING clauses in SQL?

• WHERE is used to filter rows based on a condition, while HAVING is used to filter groups based on a condition.
• WHERE is used to filter groups based on a condition, while HAVING is used to filter rows based on a condition.
• WHERE and HAVING are the same.
• WHERE and HAVING are used to join tables.

Understand: What is a subquery in SQL?

• A query within another query
• A query with multiple SELECT statements
• A query that only returns a single result
• A query that only returns aggregate data

Apply: Write an SQL statement to create a table named "employees" with columns "id", "name", "age", and "salary".

• CREATE TABLE employees (id INT, name VARCHAR(50), age INT, salary FLOAT);
• CREATE TABLE employees (id char, name VARCHAR(50), age INT, salary FLOAT);
• CREATE TABLE employees (id INT, name VARCHAR(50), age char, salary FLOAT);
• CREATE TABLE employees (id INT, name VARCHAR(50), age INT, salary char);

Apply: Write an SQL statement to insert a row into the "employees" table with the values 1, "John", 30, and 5000.

• INSERT INTO employees (id, name, age, salary) VALUES (1, "John", 30, 5000);
• INSERT INTO employees (id, name, age, salary) VALUES (aaa, "John", 30, 5000);
• INSERT INTO employees (id, name, age, salary) VALUES (1, "John", aaa, 5000);
• INSERT INTO employees (id, name, age, salary) VALUES (1, "John", 30, aaa);

Apply: Write an SQL statement to update the salary of employee with id 1 to 6000.

• UPDATE employees SET salary=6000 WHERE id=1;
• UPDATE employees GET salary=6000 WHERE id=1;
• UPDATE employees IN salary=6000 WHERE id=1;
• UPDATE employees HAVING salary=6000 WHERE id=1;

Given the following SQL statement, what will be the result set? SELECT name, age FROM employees WHERE salary > 5000;

• All employees with a salary greater than 5000, displaying only their name and age.
• All employees with a salary equal to 5000, displaying only their name and age.
• All employees with a salary less than 5000, displaying only their name and age.
• All employees, displaying only their name and age.