在使用LOAD DATA到MySQL的时候，有2种情况：
（1）在远程客户端（需要添加选项：–local-infile=1）导入远程客户端文本到MySQL，需指定LOCAL（默认就是ignore）,加ignore选项会放弃数据，加replace选项会更新数据，都不会出现唯一性约束问题。
（2）在本地服务器导入本地服务器文本到MySQL，不指定LOACL，出现唯一性约束冲突，会失败回滚，数据导入不进去，这个时候就需要加ignore或者replace来导入数据。
测试如下：
（1）本地服务器导入本地服务器文本
mysql> show create table tmp_loaddata\G;
*************************** 1. row ***************************
Table: tmp_loaddata
Create Table: CREATE TABLE `tmp_loaddata` (
`id` int(11) NOT NULL,
`name` varchar(10) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1
1 row in set (0.00 sec)
ERROR:
No query specified
mysql> select * from tmp_loaddata;
+—-+——+
| id | name |
+—-+——+
| 1 | test |
+—-+——+
1 row in set (0.00 sec)
mysql>
mysql> system cat /home/zhuxu/1.txt
1,new update
2,new update
mysql>
mysql> LOAD DATA INFILE ‘/home/zhuxu/1.txt’ INTO TABLE tmp_loaddata FIELDS TERMINATED BY ‘,’;
ERROR 1062 (23000): Duplicate entry ’1′ for key ‘PRIMARY’
# 出现唯一性约束冲突，会失败回滚
mysql> select * from tmp_loaddata;
+—-+——+
| id | name |
+—-+——+
| 1 | test |
+—-+——+
1 row in set (0.00 sec)
mysql> LOAD DATA INFILE ‘/home/zhuxu/1.txt’ IGNORE INTO TABLE tmp_loaddata FIELDS TERMINATED BY ‘,’;
Query OK, 1 row affected (0.00 sec)
Records: 2 Deleted: 0 Skipped: 1 Warnings: 0
# 使用IGNORE对于冲突的数据丢弃掉。
mysql> select * from tmp_loaddata;
+—-+————+
| id | name |
+—-+————+
| 1 | test |
| 2 | new update |
+—-+————+
2 rows in set (0.00 sec)
mysql> LOAD DATA INFILE ‘/home/zhuxu/1.txt’ REPLACE INTO TABLE tmp_loaddata FIELDS TERMINATED BY ‘,’;
Query OK, 3 rows affected (0.00 sec)
Records: 2 Deleted: 1 Skipped: 0 Warnings: 0
# 使用REPLACE对于冲突的数据进行更新。
mysql> select * from tmp_loaddata;
+—-+————+
| id | name |
+—-+————+
| 1 | new update |
| 2 | new update |
+—-+————+
2 rows in set (0.00 sec)
（2）远程客户端导入远程客户端文本
[zhuxu@xentest9-vm1 tmp]$ mysql -uzhuxu -pzhuxu test -h10.254.5.151
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 15
Server version: 5.1.47-log Source distribution
Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
This software comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to modify and redistribute it under the GPL v2 license
Type ‘help;’ or ‘\h’ for help. Type ‘\c’ to clear the current input statement.
mysql> select * from tmp_loaddata;
+—-+——+
| id | name |
+—-+——+
| 1 | test |
+—-+——+
1 row in set (0.00 sec)
mysql> system cat /tmp/2.txt
1,new update
2,new update
3,new update
mysql>
mysql> LOAD DATA INFILE ‘/tmp/2.txt’ INTO TABLE tmp_loaddata FIELDS TERMINATED BY ‘,’;
ERROR 13 (HY000): Can’t get stat of ‘/tmp/2.txt’ (Errcode: 2)
# 由于数据库服务器没有对应的文本文件，所以报错。
mysql>
mysql> LOAD DATA LOCAL INFILE ‘/tmp/2.txt’ INTO TABLE tmp_loaddata FIELDS TERMINATED BY ‘,’;
ERROR 1148 (42000): The used command is not allowed with this MySQL version
# 进去mysql远程客户端，还需要加–local-infile=1参数指定。
mysql> exit
Bye
[zhuxu@xentest9-vm1 tmp]$ mysql -uzhuxu -pzhuxu test -h10.254.5.151 –local-infile=1 –show-warnings -v -v -v \
> -e “LOAD DATA LOCAL INFILE ‘/tmp/2.txt’ INTO TABLE tmp_loaddata FIELDS TERMINATED BY ‘,’”;
————–
LOAD DATA LOCAL INFILE ‘/tmp/2.txt’ INTO TABLE tmp_loaddata FIELDS TERMINATED BY ‘,’
————–
Query OK, 2 rows affected (0.00 sec)
Records: 3 Deleted: 0 Skipped: 1 Warnings: 0
Bye
mysql> select * from tmp_loaddata;
+—-+————+
| id | name |
+—-+————+
| 1 | test |
| 2 | new update |
| 3 | new update |
+—-+————+
3 rows in set (0.00 sec)
#
[zhuxu@xentest9-vm1 tmp]$ mysql -uzhuxu -pzhuxu test -h10.254.5.151 –local-infile=1 –show-warnings -v -v -v \
> -e “LOAD DATA LOCAL INFILE ‘/tmp/2.txt’ IGNORE INTO TABLE tmp_loaddata FIELDS TERMINATED BY ‘,’”;
————–
LOAD DATA LOCAL INFILE ‘/tmp/2.txt’ IGNORE INTO TABLE tmp_loaddata FIELDS TERMINATED BY ‘,’
————–
Query OK, 0 rows affected (0.00 sec)
Records: 3 Deleted: 0 Skipped: 3 Warnings: 0
Bye
mysql> select * from tmp_loaddata;
+—-+————+
| id | name |
+—-+————+
| 1 | test |
| 2 | new update |
| 3 | new update |
+—-+————+
3 rows in set (0.00 sec)
#
[zhuxu@xentest9-vm1 tmp]$ mysql -uzhuxu -pzhuxu test -h10.254.5.151 –local-infile=1 –show-warnings -v -v -v \
> -e “LOAD DATA LOCAL INFILE ‘/tmp/2.txt’ REPLACE INTO TABLE tmp_loaddata FIELDS TERMINATED BY ‘,’”;
————–
LOAD DATA LOCAL INFILE ‘/tmp/2.txt’ REPLACE INTO TABLE tmp_loaddata FIELDS TERMINATED BY ‘,’
————–
Query OK, 4 rows affected (0.00 sec)
Records: 3 Deleted: 1 Skipped: 0 Warnings: 0
Bye
mysql> select * from tmp_loaddata;
+—-+————+
| id | name |
+—-+————+
| 1 | new update |
| 2 | new update |
| 3 | new update |
+—-+————+
3 rows in set (0.00 sec)
–EOF–