MySQL 数据库升级到8.0，注意这些参数的坑！

问题现象:

MySQL 5.7.34升级到8.0.33后，LOAD DATA LOCAL INFILE ‘XXX.csv’;执行失败，报错如下,升级之前可以正常执行:

ERROR 3948 (42000): Loading local data is disabled; this must be enabled on both the client and server sides


问题原因:

1.检查my.cnf配置文件，升级前后并没有配置local_infile参数；
2.检查当前local_infile参数值，默认值为OFF，而升级前5.7版本默认值是ON。

mysql> show variables like 'local\_infile';
+---------------+-------+
| Variable\_name | Value |
+---------------+-------+
| local\_infile | OFF |
+---------------+-------+
1 row in set (0.00 sec)


可以看下官方文档:
MySQL 8.0 local_infile参数默认值:

https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar\_local\_infile


此变量控制LOAD DATA语句的服务器端LOCAL功能。根据local_infile设置，服务器拒绝或允许在客户端启用了local的客户端加载本地数据。
**MySQL 5.7 local_infile参数默认值: **

https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html


解决方案:

local_infile参数可以动态调整
1.在线修改参数

mysql> set global local\_infile=ON;
Query OK, 0 rows affected (0.00 sec)


2.修改my.cnf参数

vi my.cnf
###在secure-file-priv 参数下一行添加
local\_infile=ON


参数测试过程如下:

数据库版本:MySQL 8.0.33
准备测试数据:

mysql> use cjc;
mysql> select \* from t1;
+------+------+---------------------+
| id | name | time |
+------+------+---------------------+
| 1 | aaa | 2024-06-03 15:18:00 |
| 2 | bbb | 2024-06-03 15:18:06 |
| 3 | ccc | 2024-06-03 15:18:10 |
+------+------+---------------------+
3 rows in set (0.00 sec)


检查参数

mysql> show variables like '%secure\_file\_priv%';
+------------------+---------------------------+
| Variable\_name | Value |
+------------------+---------------------------+
| secure\_file\_priv | /db/mysqldata/3306/file/ |
+------------------+---------------------------+
1 row in set (0.00 sec)


导出csv，默认没有列名，通过UNION ALL手动添加列名

select 'id','name','time'
UNION ALL
select id,name,time
INTO OUTFILE '/db/mysqldata/3306/file/t1a.csv' FIELDS TERMINATED BY ',' ENCLOSED BY '"' LINES TERMINATED BY '\\n'
from t1;


查看导出数据

mysql> system cat /db/mysqldata/3306/file/t1a.csv
"id","name","time"
"1","aaa","2024-06-03 15:18:00"
"2","bbb","2024-06-03 15:18:06"
"3","ccc","2024-06-03 15:18:10"


导入测试
root用户可以直接导入

mysql -uroot -p cjc


检查local_infile参数为OFF

mysql> show variables like 'local\_infile';
+---------------+-------+
| Variable\_name | Value |
+---------------+-------+
| local\_infile | OFF |
+---------------+-------+
1 row in set (0.00 sec)


mysql> create table t2 like t1;
mysql> select \* from t2;
Empty set (0.00 sec)


不影响root用户的LOAD DATA导入操作:

mysql>
LOAD DATA INFILE '/db/mysqldata/3306/file/t1a.csv'
INTO TABLE t2
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
LINES TERMINATED BY '\\n'
IGNORE 1 LINES;
Query OK, 3 rows affected (0.01 sec)
Records: 3 Deleted: 0 Skipped: 0 Warnings: 0


mysql> select \* from t2;
+------+------+---------------------+
| id | name | time |
+------+------+---------------------+
| 1 | aaa | 2024-06-03 15:18:00 |
| 2 | bbb | 2024-06-03 15:18:06 |
| 3 | ccc | 2024-06-03 15:18:10 |
+------+------+---------------------+
3 rows in set (0.00 sec)


普通用户

mysql@cjc-db-01:/db/mysqldata/dbtmpfile$mysql -ucjc -p cjc
mysql> show variables like 'local\_infile';
+---------------+-------+
| Variable\_name | Value |
+---------------+-------+
| local\_infile | OFF |
+---------------+-------+
1 row in set (0.00 sec)


需要添加LOCAL关键字

mysql>
LOAD DATA INFILE '/db/mysqldata/3306/file/t1a.csv'
INTO TABLE t2
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
LINES TERMINATED BY '\\n'
IGNORE 1 LINES;
ERROR 1045 (28000): Access denied for user 'cjc'@'localhost' (using password: YES)


默认没有导出权限

mysql>
LOAD DATA LOCAL INFILE '/db/mysqldata/3306/file/t1a.csv'
INTO TABLE t2
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
LINES TERMINATED BY '\\n'
IGNORE 1 LINES;
ERROR 3948 (42000): Loading local data is disabled; this must be enabled on both the client and server sides


修改参数

mysql> set global local\_infile=ON;
Query OK, 0 rows affected (0.00 sec)


需要先退出

mysql>
LOAD DATA LOCAL INFILE '/db/mysqldata/3306/file/t1a.csv'
INTO TABLE t2
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
LINES TERMINATED BY '\\n'
IGNORE 1 LINES;
ERROR 2068 (HY000): LOAD DATA LOCAL INFILE file request rejected due to restrictions on access.


指定–local-infile参数重新登录

mysql@cjc-db-01:/db/mysqldata/dbtmpfile$mysql -ucjc -p cjc --local-infile


可以正常导出了

mysql>
LOAD DATA LOCAL INFILE '/db/mysqldata/3306/file/t1a.csv'
INTO TABLE t2
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
LINES TERMINATED BY '\\n'
IGNORE 1 LINES;
Query OK, 3 rows affected (0.01 sec)
Records: 3 Deleted: 0 Skipped: 0 Warnings: 0


mysql> select \* from t2;
+------+------+---------------------+
| id | name | time |
+------+------+---------------------+
| 1 | aaa | 2024-06-03 15:18:00 |
| 2 | bbb | 2024-06-03 15:18:06 |
| 3 | ccc | 2024-06-03 15:18:10 |
+------+------+---------------------+
3 rows in set (0.00 sec)


其他需要注意的参数:

除了local_infile参数外，升级到MySQL 8.0后，还有哪些参数默认值发生了变化:

https://dev.mysql.com/doc/refman/8.0/en/upgrading-from-previous-series.html#upgrade-server-defaults


Changed Server Defaults
Server changes

InnoDB changes

Performance Schema changes

Replication changes

Group Replication changes