3.4

JOIN statement

A SQL statement that combines data from two tables based on a related column between them.

LEFT JOIN

Selects all rows from the left table and only matching rows from the right table.

RIGHT JOIN

Selects all rows from the right table and only matching rows from the left table.

FULL JOIN

Selects all rows from both the left and right tables, regardless of whether they match.

INNER JOIN

Selects only the rows with matching values in both tables.

UNION

Combines the results of two SELECT statements into a single result set.

Alias

A temporary name used to make column names more understandable.

ON clause

Specifies the columns used for comparison in JOIN operations.

FROM clause

Identifies the table from which to select or delete data.

Columns must have comparable data types

The data types of the columns being joined need to be the same or similar for a valid JOIN operation.