• SQL Tutorials

    SQL is an intuitive programming language with broad application scope, so solid SQL skills are essential for any data scientist. With our hands-on tutorials, you can learn the basics of SQL for free and build your relational database knowledge.

    Featured Articles

    What Are Duplicate Records in SQL?

    SQL Tutorials

    What Are Duplicate Records in SQL?

    Duplicate records in SQL, also known as duplicate rows, are identical rows in an SQL table. This means the values in each column coincide.

    Article by Martin Ganchev by Martin Ganchev 5 min read
    How to Create an Inner Join in SQL

    SQL Tutorials

    How to Create an Inner Join in SQL

    Article by Martin Ganchev by Martin Ganchev 11 min read
    Relationships between Tables in SQL

    SQL Tutorials

    Relationships between Tables in SQL

    Article by Martin Ganchev by Martin Ganchev 6 min read

    All Articles

    Learning How to Use the SQL SELF JOIN

    SQL Tutorials

    Learning How to Use the SQL SELF JOIN

    Article by Martin Ganchev by Martin Ganchev 9 min read
    How to Write SQL Subqueries

    SQL Tutorials

    How to Write SQL Subqueries

    Article by Martin Ganchev by Martin Ganchev 9 min read
    Working with the LEFT JOIN in SQL

    SQL Tutorials

    Working with the LEFT JOIN in SQL

    Article by Martin Ganchev by Martin Ganchev 12 min read
    Introducing the RIGHT JOIN in SQL

    SQL Tutorials

    Introducing the RIGHT JOIN in SQL

    Article by Martin Ganchev by Martin Ganchev 8 min read
    What Are Duplicate Records in SQL?

    SQL Tutorials

    What Are Duplicate Records in SQL?

    Article by Martin Ganchev by Martin Ganchev 5 min read
    A Few Notes on the Joins Syntax in SQL

    SQL Tutorials

    A Few Notes on the Joins Syntax in SQL

    Article by Martin Ganchev by Martin Ganchev 7 min read
    How to Create an Inner Join in SQL

    SQL Tutorials

    How to Create an Inner Join in SQL

    Article by Martin Ganchev by Martin Ganchev 11 min read
    Introduction to SQL Joins

    SQL Tutorials

    Introduction to SQL Joins

    Article by Martin Ganchev by Martin Ganchev 5 min read
    Deciding When to Use WHERE or HAVING

    SQL Tutorials

    Deciding When to Use WHERE or HAVING

    Article by Martin Ganchev by Martin Ganchev 10 min read
    How to Use the SQL ORDER BY Clause

    SQL Tutorials

    How to Use the SQL ORDER BY Clause

    Article by Martin Ganchev by Martin Ganchev 5 min read
    How to Use the SQL GROUP BY Clause

    SQL Tutorials

    How to Use the SQL GROUP BY Clause

    Article by Martin Ganchev by Martin Ganchev 8 min read
    First Steps into Data Manipulation and Operators in SQL

    SQL Tutorials

    First Steps into Data Manipulation and Operators in SQL

    Article by Martin Ganchev by Martin Ganchev 15 min read
    Unique Key and Null Values

    SQL Tutorials

    Unique Key and Null Values

    Article by Martin Ganchev by Martin Ganchev 5 min read
    Relationships between Tables in SQL

    SQL Tutorials

    Relationships between Tables in SQL

    Article by Martin Ganchev by Martin Ganchev 6 min read
    SQL Foreign Key

    SQL Tutorials

    SQL Foreign Key

    Article by Martin Ganchev by Martin Ganchev 7 min read

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