如何根据B表中的数据来更新A表？在线等待！来者有分！

[geleisi]

现数据库中有两个表A、B，
A 表结构：
| uid | username | password |
| 1 | a | |
| 2 | c | |
| 3 | f | |
B 表结构：
| uid | username | password |
| 1 | a | aa |
| 2 | b | bb |
| 3 | c | cc |
| 4 | d | dd |
| 5 | e | ee |
| 6 | f | ff |

请问如何得到这样的结果？

| uid | username | password |
| 1 | a | aa |
| 2 | c | cc |
| 3 | f | ff |

[geleisi]

谢谢mathematician(数学家)!

[mathematician]

update A,B set A.password=B.password where A.username=B.username;