SQL批量修改

[renadg]

例如：
表：t1
字段：　　username,pageid,company,branch
资料：　　　ht10 001 xxn ht10
ht10 002 xin hb10
hx11 　　001 xin hs10
　　　　　　hx11　　 002 xxn ht10
......

问题1：如何批量修改将hx11 company和branch的资料改为与ht10相同的资料？
问题2：如果没有hx11的资料，如何新增与ht10相同的资料，且username要为hx11？

[ACMAIN_CHM]

问题1：如何批量修改将hx11 company和branch的资料改为与ht10相同的资料？
假设是pageid相同的资料。否则没办法更新的了。

mysql> select * from t1;
+----------+--------+---------+--------+
| username | pageid | company | branch |
+----------+--------+---------+--------+
| ht10     | 001    | xxn     | ht10   |
| ht10     | 002    | xin     | hb10   |
| hx11     | 001    | xin     | hs10   |
| hx11     | 002    | xxn     | ht10   |
+----------+--------+---------+--------+
4 rows in set (0.00 sec)

mysql> update t1 a,t1 b
    -> set a.company=b.company,
    ->  a.branch=b.branch
    -> where a.username='hx11'
    -> and b.username='ht10'
    -> and a.pageid=b.pageid;
Query OK, 2 rows affected (0.06 sec)
Rows matched: 2  Changed: 2  Warnings: 0

mysql> select * from t1;
+----------+--------+---------+--------+
| username | pageid | company | branch |
+----------+--------+---------+--------+
| ht10     | 001    | xxn     | ht10   |
| ht10     | 002    | xin     | hb10   |
| hx11     | 001    | xxn     | ht10   |
| hx11     | 002    | xin     | hb10   |
+----------+--------+---------+--------+
4 rows in set (0.00 sec)

mysql>

[ACMAIN_CHM]

问题2：如果没有hx11的资料，如何新增与ht10相同的资料，且username要为hx11？

mysql> delete from t1 where username='hx11';
Query OK, 2 rows affected (0.06 sec)

mysql> select * from t1;
+----------+--------+---------+--------+
| username | pageid | company | branch |
+----------+--------+---------+--------+
| ht10     | 001    | xxn     | ht10   |
| ht10     | 002    | xin     | hb10   |
+----------+--------+---------+--------+
2 rows in set (0.00 sec)

mysql> insert into t1
    -> select 'hx11',pageid,company,branch from t1 where username='ht10';
Query OK, 2 rows affected (0.06 sec)
Records: 2  Duplicates: 0  Warnings: 0

mysql> select * from t1;
+----------+--------+---------+--------+
| username | pageid | company | branch |
+----------+--------+---------+--------+
| ht10     | 001    | xxn     | ht10   |
| ht10     | 002    | xin     | hb10   |
| hx11     | 001    | xxn     | ht10   |
| hx11     | 002    | xin     | hb10   |
+----------+--------+---------+--------+
4 rows in set (0.00 sec)

mysql>

[renadg]

哇，你好厉害！！！！
我怎么就想不到呢？？？嗨！
每次只会一些简单的，如果要绕弯子的，我就不会了，嗨！
不知道该如何锻炼思维能力．