UNION vs JOIN Visual
UNION vs JOIN Visual is a SQL statement in the JOIN Types category. Conceptual difference: UNION adds more rows, JOIN adds more columns. Choose based on desired output shape. The syntax is -- UNION stacks rows vertically. JOIN combines columns horizontally.. It returns conceptual comparison. A typical example: -- UNION: vertical stacking SELECT name FROM customers UNION ALL SELECT name FROM employees; -- Result: 2 columns, more rows (all names in one column) -- JOIN: horizontal combining SELECT c.name AS customer, e.name AS employee FROM customers c FULL JOIN employees e ON c.id = e.id; -- Result: 2+ columns (customer name, employee name) -- When to use: -- UNION: same data shape, different sources -- JOIN: related data… A close relative is INNER JOIN, which returns only rows where there is a match in BOTH tables. The most common JOIN type. A close relative is LEFT JOIN, which returns ALL rows from the left table and matching rows from the right. Unmatched right rows show NULL.