На диаграмме ниже показаны 7 способов использования, связанных с LEFT JOIN, RIGHT JOIN, INNER JOIN и OUTER JOIN.
Inner JOIN

SELECT <select_list>
FROM Table_A A
INNER JOIN Table_B B
ON A.Key = B.Key
FROM Table_A A
INNER JOIN Table_B B
ON A.Key = B.Key
Левое соединение

SELECT <select_list>
FROM Table_A A
LEFT JOIN Table_B B
ON A.Key = B.Key
FROM Table_A A
LEFT JOIN Table_B B
ON A.Key = B.Key
Правое соединение

SELECT <select_list>
FROM Table_A A
RIGHT JOIN Table_B B
ON A.Key = B.Key
FROM Table_A A
RIGHT JOIN Table_B B
ON A.Key = B.Key
Внешнее соединение

SELECT <select_list>
FROM Table_A A
FULL OUTER JOIN Table_B B
ON A.Key = B.Key
FROM Table_A A
FULL OUTER JOIN Table_B B
ON A.Key = B.Key
Левое исключающее соединение

SELECT <select_list>
FROM Table_A A
LEFT JOIN Table_B B
ON A.Key = B.Key
WHERE B.Key IS NULL
FROM Table_A A
LEFT JOIN Table_B B
ON A.Key = B.Key
WHERE B.Key IS NULL
Правое исключающее соединение

SELECT <select_list>
FROM Table_A A
RIGHT JOIN Table_B B
ON A.Key = B.Key
WHERE A.Key IS NULL
FROM Table_A A
RIGHT JOIN Table_B B
ON A.Key = B.Key
WHERE A.Key IS NULL
Внешнее исключающее соединение

SELECT <select_list>
FROM Table_A A
FULL OUTER JOIN Table_B B
ON A.Key = B.Key
WHERE A.Key IS NULL OR B.Key IS NULL
FROM Table_A A
FULL OUTER JOIN Table_B B
ON A.Key = B.Key
WHERE A.Key IS NULL OR B.Key IS NULL
Для получения дополнительной информации, пожалуйста, обратитесь кSQL Tutorial
