1 row affected ,表中没有冲突数据，数据被插入
主键或者唯一键没有冲突，则直接插入
mysql> replace into Student (sn,name,qq) values (140,'许攸', '2222') ;
Query OK, 1 row affected (0.00 sec)
mysql> select * from Student;
+----+------+-----------+---------+
| id | sn | name | qq |
+----+------+-----------+---------+
| 1 | 123 | 苏雪卿 | 4567890 |
| 10 | 222 | 林游星 | 12346 |
| 11 | 333 | 林斩令 | 1254546 |
| 12 | 127 | 曹操 | 3515545 |
| 14 | 128 | 许褚 | 545445 |
| 15 | 20 | xuchu | 8888 |
| 16 | 545 | 单沙禹 | 545 |
| 17 | 22 | 雪如之 | 888 |
| 18 | 140 | 许攸 | 2222 |
+----+------+-----------+---------+
9 rows in set (0.00 sec)
2 rows affected ,表中有冲突数据，删除后重新插入
主键或者唯一键如果冲突，则删除后再插入
mysql> select * from Student;
+----+------+-----------+---------+
| id | sn | name | qq |
+----+------+-----------+---------+
| 1 | 123 | 苏雪卿 | 4567890 |
| 10 | 222 | 林游星 | 12346 |
| 11 | 333 | 林斩令 | 1254546 |
| 12 | 127 | 曹操 | 3515545 |
| 14 | 128 | 许褚 | 545445 |
| 15 | 20 | xuchu | 8888 |
| 16 | 545 | 单沙禹 | 545 |
| 17 | 22 | 雪如之 | 888 |
| 18 | 140 | 许攸 | 2222 |
+----+------+-----------+---------+
9 rows in set (0.00 sec)
mysql> replace into Student (sn,name,qq) values (140,'许攸1', '2222') ;
Query OK, 2 rows affected (0.00 sec)
mysql> select * from Student;
+----+------+-----------+---------+
| id | sn | name | qq |
+----+------+-----------+---------+
| 1 | 123 | 苏雪卿 | 4567890 |
| 10 | 222 | 林游星 | 12346 |
| 11 | 333 | 林斩令 | 1254546 |
| 12 | 127 | 曹操 | 3515545 |
| 14 | 128 | 许褚 | 545445 |
| 15 | 20 | xuchu | 8888 |
| 16 | 545 | 单沙禹 | 545 |
| 17 | 22 | 雪如之 | 888 |
| 19 | 140 | 许攸1 | 2222 |
+----+------+-----------+---------+
9 rows in set (0.00 sec)