SQL for Beginners : learn SQL from scratch step by step

Retrieve data from a single table by writing a select statement, respecting the order of select, from, where, and order by clauses, and terminate each statement with a semicolon.

Explore the select clause, choosing between * or explicit columns to optimize queries, and use arithmetic expressions, operator precedence, aliases with as (including quoted spaces), and distinct for unique states.

Explore the where clause to filter data with comparison operators such as greater than, less than, equals, and not equal, including strings and dates in quotes.

Learn how to combine multiple search conditions in sql queries using and, or, not, with correct operator precedence and parentheses; explore using arithmetic expressions in the where clause.

Use the in operator to filter by a list of values, such as Virginia, Florida, and Georgia. Learn not in for exclusions and practice with a quantity in stock exercise.

Learn to use the between operator to filter data by inclusive ranges, such as points between 1000 and 3000 or birth dates between 1990-01-01 and 2000-01-01, in sql queries.

Learn how to use the like operator to filter patterns with % and _ wildcards, with case-insensitive matches, and practice filtering customers by last names, addresses, and phone numbers.

Explore the SQL regexp operator to search strings with regular expressions, using anchors ^ and $, the pipe for alternation, character classes, and ranges to match last names.

Learn to use is null and is not in sql to find records with missing attributes, such as phones or ship dates, and identify not shipped orders.

Learn to sort query results with the order by clause, using the default primary key or other columns, including aliases and expressions, in ascending or descending order.

Limit query results with the limit clause and optional offset for pagination. See how to fetch the first three customers and identify the top three loyal customers by points.

Learn how to select data from multiple tables using inner joins, aliases, and on conditions to display order details with customer names, product information, and price snapshots.

Learn to join tables across multiple databases by prefixing with the database name and joining order items with a product table in another database.

Explore how to join the employees table to itself to map employees to their managers using aliases, covering self join concepts, null manager handling, and column prefixing.

Learn to join three tables in SQL—orders, customers, and order statuses—and craft a concise report. Use an invoicing database to relate payments, clients, and payment methods for a payment summary.

Explore compound join conditions that use multiple columns to uniquely identify rows and join tables with composite primary keys, such as order_id and product_id in order items.

Compare implicit join syntax with explicit join syntax for joining orders and customers, using aliases and on conditions, and learn why explicit joins prevent unintended cross joins.

Discover how outer joins extend inner joins with left and right joins to include rows without matches, and learn when to use each for complete result sets.

Learn to perform a self join on the employees table with aliases to pair each employee with their manager, then use a left join to include employees with no manager.

Explore cross joins to combine every row from one table with every row from another, using explicit and implicit syntax with practical examples from customers, products, and shippers.

Master the union operator to combine rows from multiple queries, across same or different tables, while labeling results as active or archived and ensuring matching column counts.

Learn how column attributes shape data storage in the customers table, covering data types like varchar and char, primary key, null and default values, and auto increment behavior.

Learn to insert a row into a table using insert into, handle auto increment IDs with default or explicit values, and use null or default for optional columns.

Insert multiple rows in one statement using insert into shippers (name) values ('a'), ('b'), ('c'); the shipper_id auto increments, while you practice inserting three product rows into the product table.

Learn to insert data into multiple tables by forming a parent-child relationship between orders and order items, using last_insert_id to link items to their order.

Copy data between tables with create table as select and subqueries; archive orders and invoices, join invoices to clients, and replace client id with client name.

Learn how to update a single row in an invoices table using the update statement, set clauses, and conditions, including default values and 50% of the invoice total.

Learn to update multiple records using a general where clause, handle safe updates in MySQL Workbench, and practice bulk updates by adding points to customers born before 1990.

Use subqueries in updates to find a client id by name, then update related invoices; extend to multiple ids with in and preview before executing.

Learn to delete data safely in sql using the delete from statement, apply where clauses to target records, and employ subqueries to remove client-specific rows without erasing entire tables.