SQL Joins Visualizer

Interactive Venn diagram to understand SQL joins. Click the diagram segments or use the presets to generate SQL.

Select a Join Type
generated_query.sql
INNER JOIN
1SELECT * FROM TableA A
2INNER JOIN TableB B
3ON A.id = B.a_id

Returns records that have matching values in both tables.

Table ATable BA & B

Click segments to quickly select Excluding or Inner joins

# Visual Guide to SQL Joins

SQL Joins are fundamental to working with relational databases. They allow you to combine rows from two or more tables based on a related column between them.

This SQL Joins Visualizer uses a Venn diagram to simplify these concepts. By identifying the overlapping and non-overlapping areas of two sets (tables), you can intuitively understand what data each join type returns.

Key Concepts

  • Inner Join: The most common type. Only returns rows when there is a match in both tables.
  • Left Join: Returns all rows from the left table, and the matched rows from the right table.
  • Full Join: Returns all rows when there is a match in either one of the tables.