MySQL 快速导入数据指令load Data 详解
作者:mmseoamin日期:2023-12-11

官方文档

https://dev.mysql.com/doc/refman/8.0/en/load-data.html

样例

LOAD DATA
[LOW_PRIORITY | CONCURRENT] [LOCAL]
INFILE 'file_name'
[REPLACE | IGNORE]
INTO TABLE tbl_name
[PARTITION (partition_name [, partition_name] ...)]
[CHARACTER SET charset_name]
[{FIELDS | COLUMNS}
[TERMINATED BY 'string']
[[OPTIONALLY] ENCLOSED BY 'char']
[ESCAPED BY 'char']
]
[LINES
[STARTING BY 'string']
[TERMINATED BY 'string']
]
[IGNORE number {LINES | ROWS}]
[(col_name_or_user_var
[, col_name_or_user_var] ...)]
[SET col_name={expr | DEFAULT}
[, col_name={expr | DEFAULT}] ...]

LOCAL:是否导入本地电脑文本文件,

导入本地电脑文件:一定要启用 local_infile 参数,否则会报错。

导入非本地电脑文件:用户一定要 FILE 权限,secure_file_priv参数值如果不为空,则文件一定要在这个目录中,如果为空,则该文件只需服务器可读。

我本地使用mysql8.0。23客户端,在一切条件符合的情况下,LOAD DATA数据报错.
mysql> load data local infile '/Users/1.csv' into table ceshi.t1 ;
ERROR 2068 (HY000): LOAD DATA LOCAL INFILE file request rejected due to restrictions on access.

排错一圈,才发现踩了mysql8的一个bug,

https://bugs.mysql.com/bug.php?id=91872

  • 解决方法:

    在client端配置文件中加入

    [client]
    loose-local-infile = 1
    [mysqld]
    local_infile=1
    

    然后再在使用mysql命令行时,指定 loose-local-infile = 1 连接数据库

    mysql --local-infile=1 -uroot -p123456 -P3306 -h1.1.1.1
    

    [REPLACE | IGNORE]:如遇到唯一冲突重复处理机制

    REPLACE:覆盖写。

    IGNORE:忽略。

    如果没有指定REPLACE, IGNORE或者LOCAL,当发生错误时,会报错,并且文本余下部分不会被执行。

    示例:

    mysql> load data infile '/root/1.csv' into table ceshi.t1 ;
    ERROR 1265 (01000): Data truncated for column 'id' at row 2
    

    提示:如果要在加载数据中忽略外键约束,需要在Load data 数据之前执行SET foreign_key_checks = 0

    如果没有指定 FIELDS 或 LINES 子句,则默认值如下

    FIELDS TERMINATED BY ‘\t’ ENCLOSED BY ‘’ ESCAPED BY ‘\’

    LINES TERMINATED BY ‘\n’ STARTING BY ‘’

    提示:在 WINDOWS 系统中,想要正确的读文件需要配置 LINES TERMINATED BY ‘\r\n’,因为WINDOWS系统通常使用两个字符做为终止符。

    CHARACTER SET charset_name

    设置导入内容的字符集,默认采用character_set_database系统变量值字符集导入内容。

    提示:

    这里我踩了一个坑,我本地使用CRT连接数据库,不知为何客户端字符集是latain1了,文本中包含中文,如果以默认方式导入会出现乱码。一般情况下,不需要指定CHARACTER SET

    示例:

    root# cat 1.csv
    1,chai
    2,测试
    
    mysql> show variables like '%character%'
    -> ;
    +--------------------------+------------------------------------+
    | Variable_name | Value |
    +--------------------------+------------------------------------+
    | character_set_client | latin1 |
    | character_set_connection | latin1 |
    | character_set_database | utf8 |
    | character_set_filesystem | binary |
    | character_set_results | latin1 |
    | character_set_server | utf8 |
    | character_set_system | utf8 |
    | character_sets_dir | /usr/local/mysql57/share/charsets/ |
    +--------------------------+------------------------------------+
    8 rows in set (0.07 sec)
    
    mysql> load data local infile '/Users/1.csv' into table ceshi.t1 FIELDS TERMINATED BY ',' ENCLOSED BY '' ESCAPED BY '\\';
    Query OK, 2 rows affected (0.15 sec)
    Records: 2 Deleted: 0 Skipped: 0 Warnings: 0
    
    mysql> select * from t1;
    +----+------+
    | id | name |
    +----+------+
    | 1 | chai |
    | 2 | ?? |
    +----+------+
    2 rows in set (0.06 sec)
    
    set names utf8;
    再查询就正常了
    mysql> select * from t1;
    +----+----------------+
    | id | name |
    +----+----------------+
    | 1 | chai |
    | 2 | 测试 |
    

    FIELDS TERMINATED BY:指定两列之间分隔符,

    默认是\t ,也就是跳格,但大多时候生成的文本文件都是’,'逗号,所以在导入数据时,需要显式指定。

    示例:

    root# cat 1.csv
    1,chai
    2,测试
    
    mysql> load data local infile '/Users/1.csv' into table ceshi.t1 FIELDS TERMINATED BY ',';
    Query OK, 2 rows affected (0.20 sec)
    Records: 2 Deleted: 0 Skipped: 0 Warnings: 0
    
    mysql> select * from t1;
    +----+--------+
    | id | name |
    +----+--------+
    | 1 | chai |
    | 2 | 测试 |
    +----+--------+
    2 rows in set (0.09 sec)
    

    ENCLOSED BY:去掉字符串中包裹的符号

    示例:

    root #cat 1.csv
    1,chai
    2,测试
    3,""chayicha"
    4,"chayige"
    

    如果以之前的参数导入,则结果如下,里边的引号也会写入进去。

    mysql> load data local infile '/Users/1.csv' into table ceshi.t1 FIELDS TERMINATED BY ',';
    Query OK, 4 rows affected (0.16 sec)
    Records: 4 Deleted: 0 Skipped: 0 Warnings: 0
    
    mysql> select * from t1;
    +----+-------------+
    | id | name |
    +----+-------------+
    | 1 | chai |
    | 2 | 测试 |
    | 3 | ""chayicha" |
    | 4 | "chayige" |
    +----+-------------+
    4 rows in set (0.05 sec)
    

    ##加入 ENCLOSED BY ‘"’ 参数后,在导入时字符左右两则的双引号被删掉了。

    mysql> load data local infile '/Users/1.csv' into table ceshi.t1 
    FIELDS TERMINATED BY ',' ENCLOSED BY '"';
    Query OK, 4 rows affected (0.13 sec)
    Records: 4 Deleted: 0 Skipped: 0 Warnings: 0
    
    mysql> select * from t1;
    +----+-----------+
    | id | name |
    +----+-----------+
    | 1 | chai |
    | 2 | 测试 |
    | 3 | "chayicha |
    | 4 | chayige |
    +----+-----------+
    

    ESCAPED BY:设置转义字符,默认为\ 。

    示例:

    root#cat 1.csv
    1,chai
    2,测试
    3,"\tchayicha"
    4,wo\\a\\b\\c\tchayige
    
    mysql> load data local infile '/Users/1.csv' into table ceshi.t1 
    FIELDS TERMINATED BY ',' ENCLOSED BY '"' ESCAPED BY '\\';
    Query OK, 4 rows affected (0.13 sec)
    Records: 4 Deleted: 0 Skipped: 0 Warnings: 0
    
    mysql> select * from t1;
    +----+------------------+
    | id | name |
    +----+------------------+
    | 1 | chai |
    | 2 | 测试 |
    | 3 | chayicha |
    | 4 | wo\a\b\c chayige |
    +----+------------------+
    

    LINES STARTING BY:忽略一个公共前缀,

    如示例,只有以 cha 开头的记录正确写入到了数据库,这个参数应该不常用

    示例:

    root#cat 1.csv
    cha1,chai
    2,测试
    cha3,"yicha"
    4,chayige
    
    mysql> load data local infile '/Users/1.csv' into table ceshi.t1 
    FIELDS TERMINATED BY ',' ENCLOSED BY '"' 
    ESCAPED BY '\\' LINES STARTING BY 'cha';
    Query OK, 3 rows affected, 2 warnings (0.14 sec)
    Records: 3 Deleted: 0 Skipped: 0 Warnings: 2
    
    mysql> select * from t1;
    +----+-------+
    | id | name |
    +----+-------+
    | 1 | chai |
    | 3 | yicha |
    | 0 | NULL |
    +----+-------+
    

    LINES TERMINATED BY ‘string’:分行符,

    一般情况下遇到回行即分行 (\r\n)

    示例:

    演示一次遇到句号(。)即换行符
    root#cat 2.csv
    a,chai。2,测试。3,chayicha。
    
    mysql> load data local infile '/Users/2.csv' into table ceshi.t1 
    FIELDS TERMINATED BY ',' ENCLOSED BY '"' 
    ESCAPED BY '\\' LINES TERMINATED BY '。';
    Query OK, 4 rows affected, 4 warnings (0.15 sec)
    Records: 4 Deleted: 0 Skipped: 0 Warnings: 4
    
    mysql> select * from t1;
    +----+----------+
    | id | name |
    +----+----------+
    | 0 | chai |
    | 2 | 测试 |
    | 3 | chayicha |
    | 0 | NULL |
    +----+----------+
    4 rows in set (0.07 sec)
    

    IGNORE number {LINES | ROWS}:跳过开始的多少行才进行导入,

    如果文本中有字段名,可以跳过第一行.

    示例:

    root# cat 1.csv
    1,chai
    2,测试
    3,"yicha"
    4,chayige
    
    mysql> load data local infile '/Users/1.csv' into table ceshi.t1 FIELDS TERMINATED BY ',' ENCLOSED BY '"' ESCAPED BY '\\' IGNORE
    1 LINES;
    Query OK, 3 rows affected (0.13 sec)
    Records: 3 Deleted: 0 Skipped: 0 Warnings: 0
    
    mysql> select * from t1;
    +----+---------+
    | id | name |
    +----+---------+
    | 2 | 测试 |
    | 3 | yicha |
    | 4 | chayige |
    +----+---------+
    

    [(col_name_or_user_var [, col_name_or_user_var] …)]:手动指定要插入的列

    示例:

    root# cat 1.csv
    1,chai
    2,测试
    3,"yicha"
    4,chayige
    
    mysql> load data local infile '/Users/1.csv' into table ceshi.t1 FIELDS TERMINATED BY ',' ENCLOSED BY '"' ESCAPED BY '\\' IGNORE
    1 LINES(id,name);
    Query OK, 3 rows affected (0.16 sec)
    Records: 3 Deleted: 0 Skipped: 0 Warnings: 0
    
    mysql> select * from t1;
    +----+---------+------+
    | id | name | age |
    +----+---------+------+
    | 2 | 测试 | NULL |
    | 3 | yicha | NULL |
    | 4 | chayige | NULL |
    +----+---------+------+
    3 rows in set (0.09 sec)
    

    [SET col_name={expr | DEFAULT} [, col_name={expr | DEFAULT}] …]:在加载数据时做一些计算或更新一些其它字段值。

    示例:

    root# cat 1.csv
    1,chai
    2,测试
    3,"yicha"
    4,chayige
    

    #在写入数据时,更新age字段列

    mysql> load data local infile '/Users/1.csv' into table ceshi.t1 FIELDS TERMINATED BY ',' ENCLOSED BY '"' ESCAPED BY '\\' IGNORE
    -> 1 LINES(id,name) set age=10;
    Query OK, 3 rows affected (0.13 sec)
    Records: 3 Deleted: 0 Skipped: 0 Warnings: 0
    
    mysql> select * from t1;
    +----+---------+------+
    | id | name | age |
    +----+---------+------+
    | 2 | 测试 | 10 |
    | 3 | yicha | 10 |
    | 4 | chayige | 10 |
    +----+---------+------+
    3 rows in set (0.07 sec)
    

    #在写入数据时对数据做二次逻辑处理

    mysql> load data local infile '/Users/1.csv' into table ceshi.t1 FIELDS TERMINATED BY ',' ENCLOSED BY '"' ESCAPED BY '\\' IGNORE
    -> 1 LINES(id,@name) set name=concat(@name,1);
    Query OK, 3 rows affected (0.14 sec)
    Records: 3 Deleted: 0 Skipped: 0 Warnings: 0
    
    mysql> select * from t1;
    +----+----------+------+
    | id | name | age |
    +----+----------+------+
    | 2 | 测试1 | NULL |
    | 3 | yicha1 | NULL |
    | 4 | chayige1 | NULL |
    +----+----------+------+
    3 rows in set (0.07 sec)
    

    最后贴一个成功案例

    load data local infile 'D:\\34178517.csv' 
    into table `finance_new`            
    fields terminated by ','  
     enclosed by '"'        
    lines terminated by '\n'
    ignore 1 lines
    (@id,`uuid`, `buyer_type`, `buyer_account`, `vendor_code`, `vendor_name`, `vendor_short_name`, `policy_no`, `order_id`, `biz_id`, `parent_biz_id`, `biz_line`, `biz_type`);
    # 忽略第一行和id字段不赋值,因为表头已建好