Online Tutorial for Data Analysis and Automation
CHAPTER 30 of 30 SQL Tutorial — Free Course on Neotech Navigators This SQL reference is a complete quick-reference guide to all major SQL commands, keywords, functions, and syntax covered in our free SQL tutorial course. Bookmark this page and use it whenever you need to look up a command while writing queries. Every entry […]
CHAPTER 29 of 30 SQL Tutorial — Free Course on Neotech Navigators SQL window functions perform calculations across a set of rows that are related to the current row — without collapsing the result into a single value like GROUP BY does. They let you rank rows, compute running totals, and compare a row with […]
CHAPTER 28 of 30 SQL Tutorial — Free Course on Neotech Navigators A SQL subquery (also called a nested query or inner query) is a query placed inside another SQL statement. The inner query runs first and its result is used by the outer query. In this chapter, you will learn subqueries in WHERE, SELECT, […]
CHAPTER 27 of 30 SQL Tutorial — Free Course on Neotech Navigators The SQL EXISTS operator tests whether a subquery returns any rows at all. It returns TRUE if the subquery produces one or more rows, and FALSE if it produces zero rows. EXISTS is commonly used to check for related records in another table. […]
CHAPTER 26 of 30 SQL Tutorial — Free Course on Neotech Navigators The SQL HAVING clause filters groups created by GROUP BY based on aggregate conditions. While WHERE filters individual rows before grouping, HAVING filters after aggregation. In this chapter, you will learn the HAVING syntax, understand HAVING vs WHERE, and see practical examples with […]
CHAPTER 25 of 30 SQL Tutorial — Free Course on Neotech Navigators The SQL GROUP BY clause groups rows that share the same value in one or more columns, then lets you run aggregate functions like COUNT, SUM, AVG, MIN, and MAX on each group. In this chapter, you will learn the GROUP BY syntax, […]
CHAPTER 24 of 30 SQL Tutorial — Free Course on Neotech Navigators The SQL FULL OUTER JOIN returns all rows from both tables, matching rows where possible and filling in NULL where there is no match on either side. It combines the behavior of LEFT JOIN and RIGHT JOIN. In this chapter, you will learn […]
CHAPTER 23 of 30 SQL Tutorial — Free Course on Neotech Navigators The SQL RIGHT JOIN returns all rows from the right table and the matching rows from the left table. If there is no match, the left columns are filled with NULL. In this chapter, you will learn the RIGHT JOIN syntax, see practical […]
Learn what SQL JOINs are and why they matter. Understand how to combine rows from two or more tables using INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN with visual examples.
Learn SQL aliases to give temporary names to columns and tables using the AS keyword. Make query output readable and simplify complex queries. Free tutorial with examples.