SQL & PostgreSQL for Beginners: Learn the SQL Fundamentals

Master sql basics by exploring select and select distinct, filtering with where, between, and like, using as for aliases, and applying count and max with a practical assignment.

Learn the fundamentals of the SQL select statement to retrieve specific columns or all data from a table in PostgreSQL, with practical examples using actor and country tables.

Use the SQL select distinct statement to return only unique values from a column. Learn how it removes duplicates in tables like info, inventory, and film.

Explore how the limit clause restricts the number of rows in a query’s output, using examples that show limiting to five or fifteen rows and selecting specific columns.

Master the count function in SQL and PostgreSQL to return the number of rows in a table or column, with examples showing 599 customers and 200 actors.

Master max and min functions in SQL and PostgreSQL to return the largest or smallest values from numeric, date, and string columns using select max and select min.

Learn how to use the order by segment to sort a column in ascending or descending order in sql, with practical examples sorting by title and rental rate.

Learn to use the where statement to filter data in SQL, applying comparison and logical operators such as =, >, <, >=, <=, !=, with queries using between and not.

Learn how the between operator selects values within a range for numbers, strings, and dates; it's inclusive by default, with dates using a lower inclusive bound and upper exclusive.

Learn how to use the in operator in sql to filter by multiple values and not in to exclude them, with examples that simplify queries and improve efficiency.

Explore the local operator and pattern matching with like and ilike, using % and _ wildcards to filter rows by starting, ending, or containing characters.

Learn how to rename columns and tables with aliases using as. Aliases are temporary for a query, usable with functions and order by, but not in where.

Set up a practice sql database for a country club by importing a ready-made database with members, facilities, and bookings and running the script to create tables and insert data.

Explore essential SQL tasks in PostgreSQL: query languages, distinct payments, rental return windows, pattern matching in film titles, counting actors by last name, and category lists.

provides a sql-focused walkthrough solving assignment: fetch city_id, country_id, and city names where city_id > 200 and names end with ar___, plus film and actor queries.

Learn SQL and PostgreSQL by solving assignments: retrieve member full names, addresses, and phones; exclude guests; filter by join dates; and sort facilities by maintenance while listing five latest members.

Explore basic mathematical and string functions and operators. Learn time functions and how to extract information from time values.

Learn how to apply sum, average, and round functions in SQL and PostgreSQL to compute totals, averages, and precision, with practical examples like replacement cost and total amount spent.

Explore mathematical functions and operators in PostgreSQL, including absolute value, random value function, and trigonometric, square root, and cube root operations, with practical examples.

Learn string functions and operators in PostgreSQL, including concatenation with ||, lower and upper case, character length, and reverse. See practical examples like combining first and last names.

Explore date and time functions and operators in PostgreSQL, including current_timestamp, now, current_date, and age. Practice adding, subtracting, multiplying, and dividing date and time values with extract and other functions.

Learn how to use the extract function to retrieve subfields from timestamps or intervals, such as year, month, day, hour, and quarter, with practical PostgreSQL examples.

Learn to design and manage SQL and PostgreSQL tables, covering primary and foreign keys, constraints, inserting and updating data, and altering or deleting tables, with an end-of-section assignment.

Learn the core sql data types, including numeric, character, and time types, plus serial auto-increment keys; understand storage, ranges, and best practices for choosing types.

Learn about primary keys and foreign keys, their uniqueness and non-null requirements, how they reference and join tables, with examples from the payment, customer, staff, and rental tables.

Learn how constraints validate data in PostgreSQL by applying column and table rules, including not null, default, unique, and check, and learn to create or alter them for reliability.

Create tables using create table, define serial and varchar columns, and apply primary key, not null, and unique constraints; build student and course tables.

Learn to create tables with foreign keys in SQL, defining columns, primary keys, and references to parent tables such as the student_info and course_info for proper data linking.

Learn how to insert new records using insert into, specify columns and values, and enforce constraints with auto-increment and foreign key relationships.

Learn how to modify existing records using the update statement in SQL and PostgreSQL, including setting column values, applying where clauses, and using returning to view updated rows.

Master alter table to add or drop columns, modify column types, and rename tables or columns, using practical examples. Apply and manage constraints, including default values, on existing columns.

Learn how to delete tables and empty data using drop table, drop column, and truncate, with if exists and cascade to handle foreign keys, views, and triggers.

Explore how to group results by category using group by and learn the having clause as part of SQL queries.

Master the group by statement to aggregate data by category with sum, average, round, max, and min. See examples using customers and regions to learn select from group by syntax.

Learn to filter results with the having clause and aggregate functions like sum, average, and max, including when to use group by and why the where clause cannot filter aggregates.

Explore how to combine records from two or more tables using union, inner join, left outer join, and right outer join.

Learn how to use the union statement to combine results from multiple tables by matching identical columns, ensure data type compatibility, and understand practical examples with customers and actors.

Learn how inner join combines two tables on common values, such as emails, to return only matching rows, illustrated with address and personal info and later customer and payment examples.

Explain how the full outer join combines matching and nonmatching rows from two tables on the email column, including nulls for unmatched records and contrasts with inner and left joins.

Learn how left outer join returns all rows from left table with data from right table and nulls for unmatched rows, using address and personal info tables joined on email.

Learn how a right outer join returns matching rows and right-exclusive rows from two tables, using the email as the join key, with nulls for nonmatches.

Learn to write subqueries embedded in a main select, using in and exists, with examples like filtering employees by the average salary and two-table scenarios.

Master self join by joining a table to itself with inner join and aliases. Output each employee alongside their manager by matching employee and manager fields.

Deliver a section overview and introduce advanced concepts like views, followed by an assignment to cover the section concepts.

Learn to create and manage views as virtual tables to reuse queries, including creating, replacing, querying, dropping, renaming, and checking existence with examples like a customer info view.

Apply the case statement to label facilities as premium, regular, or free based on member cost, then count categories with sum and explore output in the facilities table.

Learn how the coalesce function handles null values by returning the first non-null argument from left to right, with unlimited arguments. Apply it to table columns to build full names.

Learn to cast a column to a data type in SQL using cast(column as type), with examples like rental_rate to varchar and 82 to integer. Casts are temporary, not permanent.

Learn to create user-defined functions in PostgreSQL with the create function command, choosing language, returns, and using declare, begin, and end blocks.

Explore the nullif function, which compares two arguments and returns null when they are equal; otherwise it returns the first argument, demonstrated with email data to find empty values.

Learn window functions in PostgreSQL, using the over clause with partition by and order by to rank prices within categories, compute running totals, and compare yearly revenues with lag.

Explore window functions in SQL, ranking and ordering data with rank and dense_rank, computing lead and lag values, and partitioning by category to rank within each category.

Apply window functions with the over clause to compute running sums and per-row totals. Join tables, count customers by district, and show each district's percentage of the total.

Import and export data with csv files in PostgreSQL by selecting a table, configuring the csv format and headers, and importing into a new or existing table.