SELECT
c.Name,
ct.Name AS NameCity,
ct.Population
FROM country AS c
LEFT JOIN city AS ct ON
ct.CountryCode = c.Code AND
ct.Population > 1000000
| Name | NameCity | Population |
| Aruba | NULL | NULL |
| Afghanistan | Kabul | 1,780,000 |
| Angola | Luanda | 2,022,000 |
| Anguilla | NULL | NULL |
| Albania | NULL | NULL |
| Andorra | NULL | NULL |
| Netherlands Antilles | NULL | NULL |
| United Arab Emirates | NULL | NULL |
| Argentina | Buenos Aires | 2,982,146 |
| ... |
| 示例用 LEFT OUTER JOIN 取出 FROM 中左表的全部行。如果右表里没有满足连接条件的记录，右表的列就是 NULL。 |