mysql中的load data infile用法

mysql中的load data infile可以快速的将文档中的数据插入数据表中，非常方便，快捷，导入300万条数据只需两三分钟。

语法如下：

LOAD DATA [LOW_PRIORITY | CONCURRENT] [LOCAL] INFILE 'file_name.txt' [REPLACE | IGNORE] INTO TABLE tbl_name

   [FIELDS
    [TERMINATED BY 'string']
    [[OPTIONALLY] ENCLOSED BY 'char']
    [ESCAPED BY 'char' ]]
   [LINES
    [STARTING BY 'string']
    [TERMINATED BY 'string']]
   [IGNORE number LINES]
   [(col_name_or_user_var,...)]
   [SET col_name = expr,...]]

一、准备数据和表

1、在数据库test中新建表 student:

create table student(id int primary key auto_increment,name varchar(20) );

2、准备数据文件 student.txt,并保存在D盘目录下student.txt内容如下:

1,quejinlong
2,dongyuncheng
3,lixuan
4,zhouwen
5,chenming

二、测试

1、最简单的情况

mysql> use test;

mysql>load data infile 'd:\\student.txt' into table student fields terminated by ',' lines terminated by '\r\n';

以上代码即可实现，将student.txt 文件中的内容快速插入到student表中。

 fields terminated by ',' lines terminated by '\r\n' 如果没有这两句，那么默认是 fields terminated by tab lines terminated by '\n'

2、ignore和replace关键字

 因为student 表中id 是关键字，唯一的，sdudent.txt 中如果有id与表中数据一致，就会冲突，所以还需要加关键字ignore 或者replace 告诉程序碰到这种情况如何操作

mysql>load data infile 'd:\\student.txt' ignore into table student fields terminated by ',' lines terminated by '\r\n';

mysql>load data infile 'd:\\student.txt' replace into table student fields terminated by ',' lines terminated by '\r\n';

3、中文字符

如果文本中有中文字符，需要将该文本的字符集编码改为utf-8（与数据库编码一致），否则会出现乱码

查看student 表字符集（其实就是查看建表命令）可以用以下命令：

<span style="font-size: 18px;">mysql></span>show create table student;

4、忽略表头前几行

假如student.txt 内容如下：

<pre name="code" class="html" style="font-size: 18px;">第一行

第二行

0,quejinlong,2015-07-25,2015-07-25 16:37:471,dongyuncheng,2015-07-25,2015-07-25 16:37:472,lixuan,2015-07-25,2015-07-25 16:37:473,zhouwen,2015-07-25,2015-07-25 16:37:474,chenming3,2015-07-25,2015-07-25 16:37:47

mysql>load data infile 'd:\\student.txt' replace into table student fields terminated by ',' lines terminated by '\r\n' ignore 2 lines;

5、Enclosed By 和 Escaped By关键字

6、load file into 的反操作：将数据表导出为文件：

 select * from student Into OutFile 'd:/studentout.txt';