MySQL preliminary, data types and SQL statements

Source: Internet
Author: User

RDBMS: relational database management system

1, database creation, deletion

2. Create a table, delete a table, modify a table

3. Creation and deletion of indexes

4. Users and Permissions

5. Data increase, deletion, change

6. Enquiry


DML: Data Manipulation language

Insert, replace, UPDATE, delete

DDL: Data Definition language

Create, ALTER, drop

DCL: Data Control Language

GRANT, REVOKE


Dbms:

Data management Independence

Effectively complete data access

Data integrity and security

Centralized data management

Concurrent storage and failure recovery

Reduce application Development Time


Syntax analysis

-->sql commands such as applications or users

||

Analyzer Plan Actuator Optimizer


Transaction manager

How files are accessed


Recovery Manager

Cache device
Lock Manager Disk space Manager


Package format

Package Manager-specific formats

RPM package, EXE format, etc.

Universal binary Format

SOURCE program

Tcp/3306,mysql user, MySQL group, installed by default in/var/lib/mysql


MySQL Client

Interactive mode

Batch mode: Execute MySQL Script

Command categories in interactive mode: Client commands and server-side commands. The server-side command must use the statement terminator, which defaults to a semicolon

Relational database objects: tables, indexes, views, constraints, stored procedures, stored functions, triggers, cursors, users, permissions, transactions

The key and main is: Table Table branch row and column field/column, table must have at least one column


Data type

Character:

CHAR (n)

varchar (n) Variable length

Binary (n) case-sensitive, national length

varbinary (n)

Text (n) literal large object, clear description of storage length

BLOB (n) binary large object

Numerical:

Exact values

Shaping modifier: Unsigned unsigned, NOT NULL

tinyint

smallint

Int

bigint

Decimal

Decimal

Approximate values

Floating point Type

Float

Double

Date Time

Date

Time

Datetime

Stamp

Boolean


Creating the database: Create databases [if not EXISTS] db_name;

Display database: show databases;

Delete databases: drop database [if not EXISTS] db_name;


Creating tables: Create TABLE Tb_name (Coll,col2 ...);

View table: Show tables from Tb_name;

View table structure: desc tb_name;

Modify table: ALTER TABLE Tb_name

Modify: Modifying properties

Change: Modify Name

Add: Adding

Drop: Delete

Help alter table--for assistance.


Insert data: INSERT INTO Tb_name (Col1,clo2 ...) values|value (' string ', num ...);

Replace into replacement

Modified data: Update tb_name set com= ' value ' where col1= ';

Delete data: Delete from Tb_name where


Choose

The Select field from the tb_name where condition;

*: Denotes all fields

Where: no where means all rows


Created by: Create user ' username ' @ ' host ' identified by ' password ';

Delete users: Drop user ' username ' @ ' host ';

User authorization: Grant permission on Db_name.tb_name to ' username ' @ ' host ' [identified by ' Password '];

View User rights: Show grant for ' username ';


Set a password for a user

1, set password for ' username ' @ ' host ' =password (' password ');

Flush privileges;

2, #mysqladmin-uusername-hhost-p PASSWORD ' PASSWORD ';

3. Update user set Password=password (' Password ') where user= ' username '


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This article is from the "ngames" blog, make sure to keep this source http://ngames.blog.51cto.com/3187187/1562164

MySQL preliminary, data types and SQL statements

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