本文章介绍了利用 mysqlimport命令来实现数据导入方法,包括txt,csv,.sql的文件的操作,有需要了解的同学可参考一下。
mysqlimport
示例
mysqlimport -uroot -p123456 test /tmp/mytbl.txt;
约定:文件名的最后一部分为表名,以上语句导入到表mytbl
mysqlimport必须指定,以上语句数据库为test
导入csv
mysqlimport -uroot -p --local --lines-terminated-by="rn" --fields-terminated-by="," --fields-enclosed-by=""" test /tmp/mytbl.csv
load data
示例
mysql> load data infile '/tmp/mytbl.txt' into table mytbl
load data可以不指定数据库
以上语句中,mysql必须有/tmp/的读权限
导入csv
mysql> load data infile '/tmp/mytbl.csv' into table mytbl fields terminated by ',' enclosed by '"' lines terminated by 'rn'
处理重复主键
替换已有值
mysql> load data infile '/tmp/mytbl.txt' replace into table mytbl fields terminated by 't' lines terminated by 'n'
表中已有则不导入
mysql> load data infile '/tmp/mytbl.csv' ignore into table mytbl fields terminated by ',' enclosed by '"' lines terminated by 'rn'
跳过文件行
以下示例为跳过第一行
mysql> load data infile '/tmp/mytbl.txt' into table mytbl ignore 1 lines;
预处理
文件data.txt内容:
Date Time Name Weight State
2006-09-01 12:00:00 Bill Wills 200 Nevada
2006-09-02 09:00:00 Jeff Deft 150 Oklahoma
2006-09-04 03:00:00 Bob Hobbs 225 Utah
2006-09-07 08:00:00 Hank Banks 175 Texas
文件必须被加载入如下的表
create table tbl
(
dt datetime,
last_name char(10),
first_name char(10),
weight_kg float,
st_abbrev char(2)
)
create table states
(
name varchar(20),
shortname char(2)
)
states 表中内容:
name shortname
Nevada NV
Oklahoma OK
Utah UT
Texas TX
insert into states
values('Nevada','NV')
,('Oklahoma','OK')
,('Utah', 'UT')
,('Texas', 'TX')
导入:
load data infile '/tmp/data.txt' into table tbl
ignore 1 lines
(@date,@time,@name,@weight_lb,@state)
set dt=concat(@date,' ',@time),
first_name=substring_index(@name,' ',1),
last_name=substring_index(@name,' ',-1),
weight_kg=@weight_lb * .454,
st_abbrev = (select shortname from states where name=@state);
结果:
mysql> select * from tbl; +---------------------+-----------+------------+-----------+-----------+
| dt | last_name | first_name | weight_kg | st_abbrev |
+---------------------+-----------+------------+-----------+-----------+
| 2006-09-01 12:00:00 | Wills | Bill | 90.8 | NV |
| 2006-09-02 09:00:00 | Deft | Jeff | 68.1 | OK |
| 2006-09-04 03:00:00 | Hobbs | Bob | 102.15 | UT |
| 2006-09-07 08:00:00 | Banks | Hank | 79.45 | TX |
+---------------------+-----------+------------+-----------+-----------+
将windows本地文件导入到下的mysql数据库,加local
load data local infile 'C:/mytbl.txt' into table mytbl fields terminated by 't' lines terminated by 'rn'

InnoDBBufferPool reduces disk I/O by caching data and indexing pages, improving database performance. Its working principle includes: 1. Data reading: Read data from BufferPool; 2. Data writing: After modifying the data, write to BufferPool and refresh it to disk regularly; 3. Cache management: Use the LRU algorithm to manage cache pages; 4. Reading mechanism: Load adjacent data pages in advance. By sizing the BufferPool and using multiple instances, database performance can be optimized.

Compared with other programming languages, MySQL is mainly used to store and manage data, while other languages such as Python, Java, and C are used for logical processing and application development. MySQL is known for its high performance, scalability and cross-platform support, suitable for data management needs, while other languages have advantages in their respective fields such as data analytics, enterprise applications, and system programming.

MySQL is worth learning because it is a powerful open source database management system suitable for data storage, management and analysis. 1) MySQL is a relational database that uses SQL to operate data and is suitable for structured data management. 2) The SQL language is the key to interacting with MySQL and supports CRUD operations. 3) The working principle of MySQL includes client/server architecture, storage engine and query optimizer. 4) Basic usage includes creating databases and tables, and advanced usage involves joining tables using JOIN. 5) Common errors include syntax errors and permission issues, and debugging skills include checking syntax and using EXPLAIN commands. 6) Performance optimization involves the use of indexes, optimization of SQL statements and regular maintenance of databases.

MySQL is suitable for beginners to learn database skills. 1. Install MySQL server and client tools. 2. Understand basic SQL queries, such as SELECT. 3. Master data operations: create tables, insert, update, and delete data. 4. Learn advanced skills: subquery and window functions. 5. Debugging and optimization: Check syntax, use indexes, avoid SELECT*, and use LIMIT.

MySQL efficiently manages structured data through table structure and SQL query, and implements inter-table relationships through foreign keys. 1. Define the data format and type when creating a table. 2. Use foreign keys to establish relationships between tables. 3. Improve performance through indexing and query optimization. 4. Regularly backup and monitor databases to ensure data security and performance optimization.

MySQL is an open source relational database management system that is widely used in Web development. Its key features include: 1. Supports multiple storage engines, such as InnoDB and MyISAM, suitable for different scenarios; 2. Provides master-slave replication functions to facilitate load balancing and data backup; 3. Improve query efficiency through query optimization and index use.

SQL is used to interact with MySQL database to realize data addition, deletion, modification, inspection and database design. 1) SQL performs data operations through SELECT, INSERT, UPDATE, DELETE statements; 2) Use CREATE, ALTER, DROP statements for database design and management; 3) Complex queries and data analysis are implemented through SQL to improve business decision-making efficiency.

The basic operations of MySQL include creating databases, tables, and using SQL to perform CRUD operations on data. 1. Create a database: CREATEDATABASEmy_first_db; 2. Create a table: CREATETABLEbooks(idINTAUTO_INCREMENTPRIMARYKEY, titleVARCHAR(100)NOTNULL, authorVARCHAR(100)NOTNULL, published_yearINT); 3. Insert data: INSERTINTObooks(title, author, published_year)VA


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Dreamweaver Mac version
Visual web development tools

WebStorm Mac version
Useful JavaScript development tools

Zend Studio 13.0.1
Powerful PHP integrated development environment