MySQL 的各种 join
| join 类型 | 备注 |
|---|---|
| left [outer] join | |
| right [outer] join | |
| `union [all | distinct]` |
| join、cross join、inner join | In MySQL, JOIN, CROSS JOIN, and INNER JOIN are syntactic equivalents (they can replace each other). In standard SQL, they are not equivalent. INNER JOIN is used with an ON clause, CROSS JOIN is used otherwise.（此说明出于mysql命令行：mysql> help join）（在 MySQL中，join、cross join、inner join这3个是等价的） |
