CRUD

Question 1

How to do an insert to the table “employees” the columns “id”, “name” and “title”?

Answer 1

INSERT INTO employees(id, name, title)
VALUES (1, ‘Allan’, ‘Engineer’);

Question 2

Does SQL support UUID?

Answer 2

NO

Question 3

Which function to user to retrieve the number of records of a column?

Answer 3

COUNT

Question 4

How to delete employee with id equal to 251 from the “employees” table?

Answer 4

DELETE from employees WHERE id = 251;

Question 5

2 ways to protect agains losing data on DELETE?

Answer 5

1. Backup
2. Soft delete

Question 6

What is a soft delete?

Answer 6

A “soft delete” is when you don’t actually delete data from your database, but instead just “mark” the data as deleted

Question 7

Write an SQL query to update the “job_title” and “salary” for an employee with the ID of 251 in the ‘employees’ table, setting the job title to ‘Backend Engineer’ and the salary to 150000?

Answer 7

UPDATE employees
SET job_title = ‘Backend Engineer’, salary = 150000
WHERE id = 251;

Question 8

What ORM stands for?

Answer 8

Object Relational Mapping

Question 9

What is an ORM?

Answer 9

A tool that allows you to perform CRUD operations on a database using a traditional programming language.