Oracle SQL - A Complete Introduction

Download and install Oracle Database Express Edition on Windows, noting that Mac is not supported. Establish a SQL Developer connection using localhost, port 1521, and the pluggable database service name.

Learn how to use the between and not between keywords in Oracle SQL to filter records by a range, including hires in 2016 and IDs between 10 and 20.

Explore the any keyword in Oracle SQL, comparing salaries against list values using all, any, greater than, less than, and not equals with practical examples.

Discover how to count records in Oracle SQL using count(*), count(1), and where clauses to determine table sizes and data occurrences.

Learn to filter groups with having after a group by in Oracle SQL, and why where cannot filter aggregates; count duplicates by last name and apply having.

Explore how the sum function adds numbers and works like count, including its use with group by. See examples summing salaries and product prices to reveal department totals.

Learn how the AVG function computes the average from numbers and that it only accepts numeric values, with examples like department salary averages grouped and ordered by the mean.

Learn how table and column aliases shorten queries, improve readability, and simplify joins in Oracle SQL, with practical examples using an employee table.

Learn how to rename query result columns with column aliases to improve readability and reporting, using optional as, double quotes for spaces, with examples like annual and monthly salary.

Learn how inner join links two tables on a common value to display only matching records from both tables, using from, join, and on, with qualifiers and aliases.

Learn how left outer join returns all records from the left table with matching or null values from the right, illustrated with customers and orders and with departments and employees.

Learn the full outer join, which combines left and right joins to return all records from both tables and shows nulls where no matches exist, using full join syntax.

Learn how natural joins automatically join on columns with the same name, see examples with employee and department tables, and understand why explicit joins are preferred for maintainability and correctness.

Learn how cartesian (cross) joins create a cartesian product by joining every record from one table to every record in another and why join conditions matter.

Explore Oracle data types, including char and varchar2, number, date, timestamp, and clob, and learn how to convert between them using to_char, to_date, and to_number with practical examples.

Learn how the case statement enables conditional logic in SQL queries, using when, then, and else, with examples classifying prices into groups and grouping regions by address stage.