How to use JOIN USING in sql to simplify JOIN ON examples

In the join SQL statement in Mysql, the syntax format of the ON clause is: table1.column_name = table2.column_name.

When the schema design adopts the same naming style for the columns of the joined table, the USING syntax can be used to simplify the ON syntax, with the format: USING(column_name).

For example:

[sql]
SELECT f.color, c.is_primary, c.is_dark, c.is_rainbow  
FROM flags f    www.2cto.com  
INNER JOIN color c ON f.color = c.color  
WHERE f.country = 'China';

is equivalent to

[sql]
SELECT f.color, c.is_primary, c.is_dark, c.is_rainbow  
FROM flags f  
INNER JOIN color c USING(color)  
WHERE f.country = 'China';

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