PostgreSQL Practice Exercises: Essential Techniques for Mastering the Framework

Here is a short practice for working with PostgreSQL:

1. Start by launching the “psql” command-line interface for interacting with the PostgreSQL database.
2. Create a new database named “mydatabase” by running the following command:

sqlCopy codeCREATE DATABASE mydatabase;

3. Connect to the “mydatabase” database by running the following command:

rCopy code\c mydatabase

4. Create a new table named “employees” with the following columns:

scssCopy codeid (integer)
name (varchar(50))
age (integer)
salary (numeric)

by running the following SQL command:

sqlCopy codeCREATE TABLE employees (
    id integer,
    name varchar(50),
    age integer,
    salary numeric
);

5. Insert the following data into the “employees” table:

pythonCopy code1, 'John Doe', 32, 65000
2, 'Jane Doe', 28, 55000
3, 'Jim Smith', 40, 75000

by running the following SQL command:

sqlCopy codeINSERT INTO employees (id, name, age, salary) VALUES
    (1, 'John Doe', 32, 65000),
    (2, 'Jane Doe', 28, 55000),
    (3, 'Jim Smith', 40, 75000);

6. Retrieve all employees who are older than 35 years old by running the following SQL command:

sqlCopy codeSELECT * FROM employees WHERE age > 35;

7. Update the salary of all employees by 10% by running the following SQL command:

sqlCopy codeUPDATE employees SET salary = salary * 1.1;

8. Delete all employees with a salary of less than 60,000 by running the following SQL command:

sqlCopy codeDELETE FROM employees WHERE salary < 60000;

By practicing these steps, you will gain experience working with the basic SQL commands for inserting, retrieving, updating, and deleting data in a PostgreSQL database. Continue to practice these commands and work on more complex examples to improve your skills and become more proficient with PostgreSQL.