在mysql中去重，其实是一个很简单的事情，来看下面的例子：mysql> DROP TABLE test;Query OK, 0 rows affected (0.01 sec)mysql> CREATE TABLE test(id INT,NAME VARCHAR(10));Query OK, 0 rows affected (0.01 sec)mysql> INSERT INTO test VALUES(1,'a1'),(2,'a2'),(3,'a3'),(4,'a4'),(1,'a1');Query OK, 5 rows affected (0.00 sec)Records: 5 Duplicates: 0 Warnings: 0mysql> SELECT * FROM test;+------+------+| id | NAME |+------+------+| 1 | a1 || 2 | a2 || 3 | a3 || 4 | a4 || 1 | a1 |+------+------+5 rows in set (0.00 sec)mysql> ALTER IGNORE TABLE test ADD UNIQUE INDEX idx_id_name (id,NAME);Query OK, 5 rows affected, 1 warning (0.02 sec)Records: 5 Duplicates: 1 Warnings: 1mysql> SHOW WARNINGS;+---------+------+-----------------------------------------------------------------+| Level | Code | Message |+---------+------+-----------------------------------------------------------------+| Warning | 1681 | 'IGNORE' is deprecated and will be removed in a future release. |+---------+------+-----------------------------------------------------------------+1 row in set (0.00 sec)mysql> SELECT * FROM test;+------+------+| id | NAME |+------+------+| 1 | a1 || 2 | a2 || 3 | a3 || 4 | a4 |+------+------+4 rows in set (0.00 sec) |