mfc将mysql查询结果取出_笔记-mysql 导出查询结果
语法：
The SELECT ... INTO OUTFILE 'file_name' [options] form of SELECT writes the selected rows to a file.
示例：
select * fromstudentsinto outfile 'test/users.csv'fields terminatedby ',' optionally enclosed by '"' --fields separated by commas and enclosed within double quotation marks
lines terminated by '\r\n'
注意：
1、该语法只能在MYSQL服务器上执行；
2、数据文件的保存位置与file_name指定的值相关。
其中，文件夹需要手动创建，文件不能为已存在的文件
原因： /不懂哇~
file_name cannot be an existing file, which among other things prevents files such as /etc/passwd and database tables from being destroyed.
额外示例说明：
当前库：
select DATABASE(); --mydemo
数据文件保存位置：
select @@datadir; --D:\Programs\MySQL\Data\
--show variables like 'datadir'
示例：
1、”fname” - %datadir%/
file_name='users.csv'
file_path= D:\Programs\MySQL\data\mydemo\
2、”/fname” – rootd_%datadir%/
file_name='/users.csv'
file_path=D:\
3、”folder_name/fname” – %datadir%/folder_name
file_name='test/users.csv'
file_path= D:\Programs\MySQL\data\test\
其中，此处报错：Can't create/write to file 'D:\Programs\MySQL\Data\test\users.csv' (Errcode: 2)
根据错误编号Errcode，定位错误原因：需要手动创建文件夹 test
> perror 2OS error code2: No such file or directory
4、”/folder_name /fname” – rootd_%datadir%/folder_name
file_name='/test/users.csv'
file_path= D:\test\
导入外部文件
load data infile 'test/users.csv' REPLACE
into tablestudents
fields terminatedby ',' optionally enclosed by '"'lines terminatedby '\r\n'
参考：