数据导入
1.mysqlimport命令行导入数据
在使用mysqlimport命令导入数据时，数据来源文件名要和目标表一致，不想改文件名的话，可以复制一份创建临时文件，示例如下。
建立一个文本users.txt，内容如下：
1001,张三,zhangsan@163.com 1002,李四,zhangsan@126.com 1003,王五,zhangsan@qq.com 1004,李白,zhangsan@hotmail.com
创建一个表users
mysql> create table if not exists users(
-> id int(11) not null default 1000,
-> name varchar(50),
-> email varchar(50)
-> );
Query OK, 0 rows affected (0.15 sec)
使用mysqlimport将users.txt中数据导入users表
PS F:\> mysqlimport -u root -p123456 zz --default-character-set=gbk --fields-terminated-by=‘,‘ f:\users.txt zz.users: Records: 3 Deleted: 0 Skipped: 0 Warnings: 0 -----------------------------验证---------------------------------- mysql> select * from users\G *************************** 1. row *************************** id: 1003 name: 王五 email: wangwu@163.com *************************** 2. row *************************** id: 1001 name: 张三 email: zhangsan@163.com *************************** 3. row *************************** id: 1002 name: 李四 email: lisi@hotmail.com
分列，使用--fields-terninated-by参数来指定每列的分隔符，例如：
1004#李白#libai@hotmail.com --文本内容 ---------------------------验证---------------------------------- PS F:\> mysqlimport -u root -p7758520 zz --fields-terminated-by=‘#‘ f:\users.txt zz.users: Records: 1 Deleted: 0 Skipped: 0 Warnings: 0 mysql> select * from users; +------+------+-------------------+ | id | name | email | +------+------+-------------------+ | 1004 | 李白 | libai@hotmail.com | +------+------+-------------------+ 1 row in set (0.00 sec)
如果列值中出现了分隔符，例如 1004"#李#白"#"[email protected]"
PS F:\> mysqlimport -u root -p7758520 zz --fields-terminated-by=‘#‘ --fields-enclosed-by=\" f:\users.txt
如果遇到一条记录有多行，则可以使用--lines-terminated-by=name来指定行的结束符
PS F:\> mysqlimport -u root -p7758520 zz --fields-terminated-by=‘#‘ --fields-enclosed-by=\" --lines-terminated-by=‘xxx\n‘ f:\users.txt
2.使用Load Data语句导入数据
Load Data 语句的使用语法如下：
LOAD DATA [LOW_PRIORITY | CONCURRENT] [LOCAL] INFILE ‘file_name‘
[REPLACE | IGNORE]
INTO TABLE tbl_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,...)]
[SET col_name = expr,...]
刚开始看到这个语法吓了一跳，这么长，其实没这么复杂，一般只需记住LOAD DATA INFILE file_name INTO TABLE tb_name这个即可，示例：
首先创建一个表sql_users，利用上面的users表复制一下
mysql> create table sql_users as select * from users; Query OK, 1 row affected (0.06 sec) Records: 1 Duplicates: 0 Warnings: 0 mysql> truncate table sql_users; Query OK, 0 rows affected (0.00 sec) mysql> select * from sql_users; Empty set (0.00 sec)
文本sql_users.txt
1004#李白#[email protected] 1005#杜牧#[email protected] 1006#杜甫#[email protected] 1007#苏轼#[email protected]
利用LOAD DATA INFILEE语句导入数据
mysql> load data infile ‘f:\sql_users.txt‘ into table sql_users fields terminated by ‘#‘; Query OK, 4 rows affected (0.00 sec) Records: 4 Deleted: 0 Skipped: 0 Warnings: 0 mysql> select * from sql_users; +------+------+--------------------+ | id | name | email | +------+------+--------------------+ | 1004 | 李白 | [email protected] | 1005 | 杜牧 | [email protected] | 1006 | 杜甫 | [email protected] | 1007 | 苏轼 | [email protected] | +------+------+--------------------+ 4 rows in set (0.00 sec)
如果在导入数据时，遇到字符串无法识别时，一般都是字符集有问题，使用charset选项即可解决
mysql> load data infile ‘f:\sql_users.txt‘ into table sql_users fields terminated by ‘#‘; ERROR 1366 (HY000): Incorrect string value: ‘\xC0\xEE\xB0\xD7‘ for column ‘name‘ at row 1 --------------------------------字符集不一样----------------------- mysql> load data infile ‘f:\sql_users.txt‘ into table sql_users character set gbk fields terminated by ‘#‘; Query OK, 4 rows affected (0.03 sec) Records: 4 Deleted: 0 Skipped: 0 Warnings: 0
LOAD DATA INFILE命令默认要导入数据存放在服务上，如果要导入客户端的数据，可以指定LOCAL，那么mysql将从客户端读取数据，这样的方式会比服务器上操作要慢一点，因为客户端的数据需要通过网络传输到服务器。
mysql> load data local infile ‘f:\sql_users.txt‘ into table sql_users fields terminated by ‘#‘;
如果需要忽略与主键值重复的记录值或者替换重复值，可以使用IGNORE或REPLACE选项，但是LOAD DATA INFILE命令语法中有两处IGNORE关键字，前面一个是用来此功能的，后面一个用来指定需要忽略的前N条记录。
--------------------文本中的内容---------- PS F:\> MORE .\sql_users.txt 1004#李白#libai@hotmail.com 1005#杜牧#dumu@hotmail.com 1006#杜甫#dufu@hotmail.com 1007#苏轼#sushi@hotmail.com 1007#苏轼#sushi@hotmail.com -----------------------导入------------------- mysql> LOAD DATA INFILE ‘F:\sql_users.txt‘ IGNORE INTO TABLE sql_users CHARACTER SET GBK FIELDS TERMINATED BY ‘#‘; Query OK, 4 rows affected (0.00 sec) Records: 5 Deleted: 0 Skipped: 1 Warnings: 0 mysql> select * from sql_users; +------+------+--------------------+ | id | name | email | +------+------+--------------------+ |1004 | 李白 | libai@hotmail.com |005 | 杜牧 | dumu@hotmail.com |006 | 杜甫 | dufu@hotmail.com |1007 | 苏轼 | sushi@hotmail.com +------+------+--------------------+ 4 rows in set (0.00 sec)
如果不想导入数据文件的前N行，使用IGNORE N LINES来处理
mysql> SELECT * FROM SQL_USERS; Empty set (0.00 sec) mysql> LOAD DATA INFILE ‘F:\sql_users.txt‘ IGNORE INTO TABLE sql_users CHARACTER SET GBK FIELDS TERMINATED BY ‘#‘ IGNORE 1 LINES; Query OK, 3 rows affected (0.00 sec) Records: 4 Deleted: 0 Skipped: 1 Warnings: 0 mysql> SELECT * FROM SQL_USERS; +------+------+--------------------+ | id | name | email | +------+------+--------------------+ |005 | 杜牧 | dumu@hotmail.com |006 | 杜甫 | dufu@hotmail.com |1007 | 苏轼 | sushi@hotmail.com +------+------+--------------------+ 3 rows in set (0.00 sec)
如果在数据文件中记录行头有某些字符，又不想被导入，可以使用LINES STARTING BY来解决，但是如果某行记录不包含这些字符的话，那么这行记录也会被忽略。
---------------文本---------------- PS F:\> MORE .\sql_users.txt zzz1004#李白#libai@hotmail.com 1005#杜牧#dumu@hotmail.com zzz1006#杜甫#dufu@hotmail.com 1007#苏轼#sushi@hotmail.com zzz1007#苏轼#sushi@hotmail.com ---------------验证----------------------- mysql> select * from sql_users; Empty set (0.00 sec) mysql> LOAD DATA INFILE ‘F:\sql_users.txt‘ IGNORE INTO TABLE sql_users CHARACTER SET GBK FIELDS TERMINATED BY ‘#‘ LINES STARTING BY ‘zzz‘; Query OK, 3 rows affected (0.00 sec) Records: 3 Deleted: 0 Skipped: 0 Warnings: 0 mysql> select * from sql_users; +------+------+--------------------+ | id | name | email | +------+------+--------------------+ |1004 | 李白 | libai@hotmail.com |006 | 杜甫 | dufu@hotmail.com | 1007 | 苏轼 | sushi@hotmail.com | +------+------+--------------------+ 3 rows in set (0.00 sec)
数据文件为Excel文件的处理，首先将Excel文件保存为CSV格式，这样字段间都是用逗号隔开的，再进行处理。
-----------excel转换成CSV的数据-------------
PS F:\> MORE .\stu.csv
学号,姓名,班级
4010404,祝小贤,A1012
4010405,肖小杰,A1013
4010406,钟小喜,A1014
4010407,钟小惠,A1015
--------------------进行导入--------------------
mysql> CREATE TABLE stu(
-> sno int not null primary key,
-> sname varchar(30),
-> class char(6)
-> );
Query OK, 0 rows affected (0.05 sec)
mysql> LOAD DATA INFILE ‘F:\stu.csv‘ INTO TABLE stu CHARACTER SET GBK FIELDS TERMINATED BY ‘,‘ IGNORE 1 LINES;
Query OK, 4 rows affected (0.00 sec)
Records: 4 Deleted: 0 Skipped: 0 Warnings: 0
mysql> SELECT * FROM STU;
+---------+--------+--------+
| sno | sname | class |
+---------+--------+--------+
|4010404 | 祝小贤 | A1012
|4010405 | 肖小杰 | A1013
|4010406 | 钟小喜 | A1014
|4010407 | 钟小惠 | A1015
+---------+--------+--------+
4 rows in set (0.00 sec)
数据文件列值中有特殊符号，使用enclosed by来处理。例如，列值中有分隔符
---------------------文本-------------------- PS F:\> MORE .\stu.csv 学号,姓名,班级 4010404,祝小贤,"A1012,01" 4010405,肖小杰,"A1013,02" 4010406,钟小喜,"A1014,03" 4010407,钟小惠,"A1015,04" --------------------导入------------------------ mysql> select * from stu; Empty set (0.00 sec) mysql> LOAD DATA INFILE ‘F:\stu.csv‘ INTO TABLE stu CHARACTER SET GBK FIELDS TERMINATED BY ‘,‘ ENCLOSED BY ‘"‘ LINES TER MINATED BY ‘\r\n‘ IGNORE 1 LINES; Query OK, 4 rows affected (0.01 sec) Records: 4 Deleted: 0 Skipped: 0 Warnings: 0 mysql> select * from stu; +---------+--------+----------+ | sno | sname | class | +---------+--------+----------+ | 4010404 | 祝小贤 | A1012,01 | | 4010405 | 肖小杰 | A1013,02 | | 4010406 | 钟小喜 | A1014,03 | | 4010407 | 钟小惠 | A1015,04 | +---------+--------+----------+ 4 rows in set (0.00 sec)
数据导入时换行符的问题，在上面的示例中，有几个数据导入到表中后，查询时结果显示有点别扭，不知大家注意到了没。
在Windows系统中，文本格式的换行符有"\r+\n"组成，而在linux系统中，换行符是"\n"。因此出出现上述问题，解决方法就是指定换行符LINES TERMINATED BY。
mysql> LOAD DATA INFILE ‘F:\stu.csv‘ INTO TABLE stu CHARACTER SET GBK FIELDS TERMINATED BY ‘,‘ ENCLOSED BY ‘"‘ LINES TERMINATED BY ‘\r\n‘ IGNORE 1 LINES;
表的列数多余数据文件中的列数，解决方法就是指定要导入到表的字段，如下所示
mysql> desc stu; --查看表结构 +-------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+-------------+------+-----+---------+-------+ | sno | int(11) | NO | PRI | NULL | | | sname | varchar(30) | YES | | NULL | | | class | varchar(20) | YES | | NULL | | | age | int(11) | YES | | NULL | | +-------+-------------+------+-----+---------+-------+ ---------------------导入数据------------------- mysql> LOAD DATA INFILE ‘F:\stu.csv‘ INTO TABLE stu CHARACTER SET GBK FIELDS TERMINATED BY ‘,‘ ENCLOSED BY ‘"‘ LINES TER MINATED BY ‘\r\n‘ IGNORE 1 LINES (SNO,SNAME,CLASS); Query OK, 4 rows affected (0.00 sec) Records: 4 Deleted: 0 Skipped: 0 Warnings: 0 mysql> SELECT * FROM STU; +---------+--------+-------+------+ | sno | sname | class | age | +---------+--------+-------+------+ | 4010404 | 祝小贤 | A1012 | NULL | | 4010405 | 肖小杰 | A1013 | NULL | | 4010406 | 钟小喜 | A1014 | NULL | | 4010407 | 钟小惠 | A1015 | NULL | +---------+--------+-------+------+ 4 rows in set (0.00 sec)
如果是表的列数少于数据文件中的列数呢，解决办法可以指定用户变量来接收多余的列值，如下
-------------------文本数据------------------------- PS F:\> MORE .\stu.csv 学号,姓名,班级 4010404,祝小贤,"A1012",20,male 4010405,肖小杰,"A1013",22,female 4010406,钟小喜,"A1014",24,male 4010407,钟小惠,"A1015",26,female ------------------导入----------------------------- mysql> LOAD DATA INFILE ‘F:\stu.csv‘ INTO TABLE stu CHARACTER SET GBK FIELDS TERMINATED BY ‘,‘ ENCLOSED BY ‘"‘ LINES TER MINATED BY ‘\r\n‘ IGNORE 1 LINES (SNO,SNAME,CLASS,AGE,@GENDER); Query OK, 4 rows affected (0.05 sec) Records: 4 Deleted: 0 Skipped: 0 Warnings: 0 mysql> SELECT * FROM STU; +---------+--------+-------+------+ | sno | sname | class | age | +---------+--------+-------+------+ | 4010404 | 祝小贤 | A1012 | 20 | | 4010405 | 肖小杰 | A1013 | 22 | | 4010406 | 钟小喜 | A1014 | 24 | | 4010407 | 钟小惠 | A1015 | 26 | +---------+--------+-------+------+ 4 rows in set (0.00 sec)
如果表的列数与数据文件的不同，且某些字段类型都不一致，那怎么解决呢？方法如下：
------------------文本---------------------- PS F:\> MORE .\stu.csv 学号,姓名,班级 4010404,祝小贤,"A1012",20,male,信息学院 4010405,肖小杰,"A1013",22,female,外院 4010406,钟小喜,"A1014",24,male,会计学院 4010407,钟小惠,"A1015",26,female,商学院 --------------------处理------------------------- mysql> desc stu; //表结构 +--------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------+-------------+------+-----+---------+-------+ | sno | int(11) | NO | PRI | NULL | | | sname | varchar(30) | YES | | NULL | | | class | varchar(20) | YES | | NULL | | | age | int(11) | YES | | NULL | | | gender | tinyint(4) | YES | | NULL | | +--------+-------------+------+-----+---------+-------+ 5 rows in set (0.01 sec) mysql> LOAD DATA INFILE ‘F:\stu.csv‘ INTO TABLE stu CHARACTER SET GBK FIELDS TERMINATED BY ‘,‘ ENCLOSED BY ‘"‘ LINES TER MINATED BY ‘\r\n‘ IGNORE 1 LINES (SNO,SNAME,CLASS,AGE,@GENDER,@x) SET GENDER=IF(@GENDER=‘MALE‘,1,0); Query OK, 4 rows affected (0.09 sec) Records: 4 Deleted: 0 Skipped: 0 Warnings: 0 mysql> SELECT * FROM STU; +---------+--------+-------+------+--------+ | sno | sname | class | age | gender | +---------+--------+-------+------+--------+ | 4010404 | 祝小贤 | A1012 | 20 | 1 | | 4010405 | 肖小杰 | A1013 | 22 | 0 | | 4010406 | 钟小喜 | A1014 | 24 | 1 | | 4010407 | 钟小惠 | A1015 | 26 | 0 | +---------+--------+-------+------+--------+ 4 rows in set (0.00 sec)
数据导出
数据导出比较简单，只要会SELECT ...INTO OUTFILE语句即可，例如
mysql> SELECT * FROM STU INTO OUTFILE "F:\stu_bak.txt" CHARACTER SET GBK FIELDS TERMINATED BY ‘##‘ LINES TERMINATED BY‘\r\n‘; Query OK, 4 rows affected (0.00 sec) -------------------------------stu_bak.txt----------------------- PS F:\> MORE .\stu_bak.txt 4010404##祝小贤##A1012##20##1 4010405##肖小杰##A1013##22##0 4010406##钟小喜##A1014##24##1 4010407##钟小惠##A1015##26##0
还有一个SELECT...INTO DUMPFILE，这个语句也是将数据导出到文件，但是不能格式化语句，如FIELDS,LINES这些，它是将数据原汁原味输出到文件。但是只能输出一个记录，用处不大。
时间： 2024-10-27 08:11:42