Mysql- database

MYSQL acquaintance:

• Database Advantages:

  • Stability Program: Program crash will not affect the data and services

  • Data consistency: all the data stored together

  • Concurrency: concurrent database itself

  • Efficiency: CRUD efficient use of database data is higher

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• Database Category:

  • Relational database (table structure):

    • Characteristics of relatively slow, strong correlation between data

    • mysql，oracle，sqlserver，sqllite，accesse

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  • Non-relational databases (key: value):

    • Characteristics of relatively fast, small data associated with the data

    • redis, mongodb, memcache (out of - memory level, eliminated),

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• Mysql statement is divided into three types:

  • DDL statements, database definition language: databases, tables, views, indexes, stored procedures, e.g. create, drop, alter

  • DML statements, database manipulation language: insert, delete, update, query data, insert, delete, update, select

  • DCL statement, the database control language: user's access rights, grant, revoke

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Mysql installation:

• Mysql installation:

  • Path can not have Chinese

  • Path can not have special characters

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• InnoDB to create databases and tables generated after file:

  • Database: folder table: File

  • db.opt character set

  • .frm table structure

  • Each tablespace .idb a table (table data and table index)

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• account number:

  • Delete anonymous account (security):

    • drop user ''@localhost;

    • drop user 'root'@'::1';

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  • Setting administrator account:

    • 1, using the administrator login: mysql -uroot

    • 2, modify the administrator password: set password = password ( "123");

    • 3, sign-on administrator account: mysql -uroot -p123

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  • Create a database account:

    • View created account: select user (); select host, user from mysql.user;

    • Create an account:

      • create user "haiyang"@"192.168.13.%" identified by "123";

      • flush privileges;

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    • grant account Empowerment (CRUD):

      • All grant all permissions

      • There is an account Empowerment: grant select on mysql * to "hai" @ "192.168.13%.".

      • No account creation, and give read permission:

        • grant select on mysql.* to "hai"@"192.168.13.%" identified by "123";

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      • Create a login ip address specified, you can only specify the ip address can log:

        • mysql -uhaiyang -p123 -h192.168.13.144

    • Permissions can be assigned to the account recovery ........

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Database operations:

• Simple library operations:

  • Create a library: create database ftp;

  • Switch libraries: use the library name;

  • Delete Library: drop database database name;

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• Simple table operations:

  • Creating format: create table table name (id int, name char (character))

  • Create a table: create table table name (id int, name char (12));

  • View Table: show tables;

  • View table structure: desc table; = describe table name;

  • For more information see the table structure: show create table userinfo;

  • View Jian table statement: show create table table name;

  • Delete tables: drop table table name;

  • Modify the table: alter table table name rename haha;

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• CRUD statements:

  • increase

    • Data Insert: insert into table values ​​(1, "haiyang");

    • Insert two: insert into table values ​​(1, "haha"), (2, "dudu");

    • View table data: select * from table name;

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  • delete:

    • delete from 表名;

    • Remove the data ID in the table 1: delete from table where id = 1;

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  • change:

    • Examples of errors: update userinfo set name = "aa"; (ID is not specified all modifications)

    • The modified table data ID field: update table set name = "fafa" where id = 2;

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  • check:

    • delete from 表名;

    • Check all the data in the table: select * from table name;

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