And in the knowledge database
1: What is the data (Data)
Symbol records describe things is called data, this symbol can be numbers, text, pictures, sound, language, etc.
2: What is the database (DataBase, referred to as DB)
The database is stored in the data warehouse, the library is normally stored on a computer storage device, and the data is stored in a certain format
3: What is a database management system (DataBase Mangement System abbreviation: DBMS)
Relational data: there can be between data associated with the data and limitations; databases are usually relational table structure, that is, means that you are using relational data when
Non-relational database: based on key-value store, there is no table structure
Relational: such as: sqllite, db2, oracle, access, sq1 sever, MySQL, note: sql statement General
Non-relational: mongodb (document type data, very close to non-relational data relational), redis, memcache
Second, the acquaintance MySQL
1, MySQL is a relational database management system, developed by the Swedish company MySQL AB, Oracle's currently owned company
What mysql that?
Is based on a socket (socket) prepared by the c / s architecture of the software, is essentially a web-based application to communicate
Server
- based socket communication
- messaging
-SQL statement (a common standard)
client
- based socket communication
- messaging
-SQL Statement
ps: MySQL only supports MySQL client to operate, but also support other programming languages directly manipulate
python, java, c ++, php, c, etc., just not the same syntax
2, related concepts:
MySQL can actually see it as a software support remote file operations
Library: that folder
Table: is the file
Record: data in the file line by line in a section called the record
Header: is the first row of the table
Fields: Field Name Field Type +
Third, the installation and use of MySQL
In the IT industry, Do not try to install the latest version of the software. Unstable, not necessary Bug prone, and difficult to repair
1, substantially the steps of:
Download the official website (5.7 / 5.6 version) >> Download >> Open unzip find mysl.exe bin directory, copy the path environment variable to add >>> >>>
Open CMD >>> mysqld with administrator privileges to open the server >> mysql -uroot -p open a connection to the server to server >> made into a system service (boot)
2, start command : D: (switching to the D drive) >>> cd + exe file folder path where the input mysql.exe or mysqld.exe >>
3, Common operation command:
(1) mysql sql statement is a semicolon; for the end, do not lose a semicolon, by default you do not have losers, will continue waiting for input,
(2) When the command input can be used when error \ c cancels the previous command cancel
(3) \ s View mysql server simple configuration
4, client logon : mysql -h 127.0.0.1 -P 3306 -uroot -p can be abbreviated: mysql -uroot -p
If you do not enter a user name and password by default is landed guest mode function can be used rarely
5, the client logout : exit; quit;
6, to see all the databases: show databases;
7, view a process : tasklist | findstr name (mysql or mysqld)
8, kill the process: taskkill / F / PID process ID (dynamic)
to start the path to the file where the environment variable added to the system's
Note: After configuring a while to restart the mysql server and terminal cmd
production system services you must be the Administrator cmd terminal
without a password
mysqladmin -uroot -p password 123
the password case
mysqladmin -uroot -p123 (original password) password 123456
mysqld --skip-grant-tables skip start the server authorization table
2. modify the administrator password corresponding to the user
update mysql.user set password = password (123 ) where user = 'the root' and Host = 'localhost';
3. the server again to close the current username and password verification as to start
4. in the normal manner username and password server connected mysql
13: Profile
suffix configuration files are usually ini end
it you can create a configuration file my.ini
mysql server will automatically load the configuration in your configuration file in the startup my.ini
# Above mysql5.5: modifications subject to change [mysqld] Character -set-Server = UTF8 collation -server = utf8_general_ci [Client] default -CHARACTER-SET = UTF8 [MySQL] default -CHARACTER-SET = UTF8 # 2. Restart service # 3 View modify the result: \ S
Can also be in the configuration file, the customer service end user and password in mysql bind directly to run as an administrator to view
Fourth, the basic operation of the database:
Library: similar to folders
By create database db1; investigation show databases; check all show create database db1; check single change ALTER Database charset = DB1 'GBK' ; modified encoding puncturing drop database db1; deletion library
Table: Similar documents
You need to be specified when creating a table of library specify the library: use library name to view the current, although in the library: select database () by create table userinfo (id int, name char); check show tables; all of the following to view a library table Show Create table UserInfo; desc UserInfo; <==> DESCRIBE UserInfo; modified ALTER Modify table UserInfo name char ( 32 ); puncturing drop table userinfo;
Record: data in the file line by line in a section called the record
Create to a library or specify an existing library switch to this library to create the table and then the operation record
Create Database DB1; Create Table UserInfo (ID int, name char ( 32 ), password int); growth INSERT INTO UserInfo values ( . 1 , ' Jason ' , 123 ); inserting a single data iNSERT INTO UserInfo values ( . 1, ' Jason ' , 123), (2, ' Egon ' , 123), (. 3, ' Tank ' , 123 ); inserting a plurality of data search the SELECT * from UserInfo; to query all field information name SELECT from UserInfo; field information query specifies SELECT ID, name from UserInfo ID = WHERE. 1 or name = Tank; information field with filter conditions change Update UserInfo SET name = ' Kevin ' WHERE ID =. 1 ; modify a data field information Update UserInfo SET name = ' Jason ' , password = WHERE ID = 666. 1 ; a plurality of data fields modify delete delete from UserInfo ID = WHERE. 1 ; designated qualified data deletion delete from UserInfo; delete all the data in the table