SQL for Newcomers - A Crash Course

download PostgreSQL, select your operating system (Linux, Mac, or Windows), and choose 64-bit or 32-bit Windows after checking system type, then download the installer.

Install PostgreSQL on your local machine by accepting the default directory and data folder, set a strong superuser password, note port 5432, uncheck stack builder, and finish installation.

Learn how to download and install SQLectron, the cross-platform editor for running SQL scripts, including choosing the right installer (exe, tar, rpm, deb) for Windows, macOS, and Linux.

Install SQLectron, launch the downloaded tool, and wait for the installation to finish. Then learn how to connect to the database.

Connect to PostgreSQL by configuring credentials, including a database user (admin or super user) and password, selecting a database (default name), and setting host (localhost or 127.0.0.1) and port (5432).

Connect to PostgreSQL using SQLectron by configuring a new connection with localhost and port 5432, a superuser, and the installed password, then test and save to start the course.

Import course data using SQLectron by downloading the data file and running scripts to build the database, tables, and seed data. Refresh the public schema to reveal departments and employees.

For Windows 32-bit users, download and install The Beaver community edition, configure the PostgreSQL connection, download the sample dataset, and run queries like select star from employees to verify data.

Learn to fetch data with the select statement from the employees table, choosing all columns or specific ones like first name, last name, and phone, for clean, query-driven results.

Understand what a database is and how tables organize data, including relational and tabular structures. See how sql enables access, updates, and querying within an rdbms.

Explore data types in sql for newcomers, numbers, dates, and strings, with examples like salaries and emails, and learn how proper typing improves filtering.

Extract data from a database using salary-based queries, identifying employees with base salaries above or equal to 5000, between 1000 and 2000, or with salaries of 1600, 2700, or 4200.

Learn to filter the employees table with the where clause. Filter on base_salary using greater than, greater than or equal to, not equal to, and less than.

Learn to filter employee base salaries using the between operator in sql, selecting salaries between 1000 and 2000 with a clear where clause.

learn how to filter data by a set of values using the in keyword in SQL, applying to base salary values like 1600, 2700, and 4200.

Learn how to filter employee data by strings in SQL, using last_name, state, and phone with single quotes and case sensitivity to retrieve precise results.

Practice creating a full name by concatenating first and last names and aliasing the result as a clear column, using select statements that don’t alter the table.

Learn to order query results with the order by clause, sorting by any column or expression in ascending or descending order, and handle aliases with spaces using quotes or brackets.

Learn how to sort query results by multiple columns in SQL, using ascending and descending orders, with examples on job title, full name, salary, and hire date.

Limit fetched records with the limit clause to save memory on large tables, and use where and order by to retrieve the top 10 employees by base salary.

Learn how null values differ from empty strings in sql, filter with is null or is not null, and identify and update missing phone numbers in the employees table.

Discover how functions in SQL translate inputs into outputs, from single-row operations like upper and trim to multi-row aggregates like sum, with data cleaning and transformation examples.

Apply the sum function to the employees table to total numeric fields like base salary, returning the total or filtered by state with a where clause.

Learn how the avg (average) function computes the mean base salary from the employees table, filter by states, and compare overall versus state-specific averages using aliases.

Explore the sql count function to tally rows and field values, using count(*) and count(field) with examples from employees and salary data, and note how empty values are handled.

Calculate per-state employee counts by applying the count function with a group by clause on state, turning raw records into state-level metrics such as California 55 and Texas 26.

Group by multiple dimensions to count employees by state and job title, then sort results by count descending, followed by job title and state for clarity.

Explore SQL basics in this newcomers crash course and discover a full mastery course with over 11 hours of video to practice and master SQL.