3 MySQL SQL Basics

Directory

1. SQL Overview
2. Database operations
3. Table Operations
4. Record operations

1. SQL Overview

SQL, Structured Query Language (structured Query Language), a database query and programming language for accessing data and querying, updating, and managing relational database systems. Case insensitive.

It consists of 6 main parts:
1. Data definition Language (DDL): common reserved words create and drop.
2. Data Query Language (DQL): SELECT, ORDER by.
3. Data manipulation Language (DML): Insert,update and delete.
4. Data Control Language (DCL): Grant,revoke.
5. Transaction processing Language (TPL): BEGIN transaction,commit and rollback.
6. Pointer Control Language (CCL): DECLARE cursor,fetch into.

SQL main operation: increase, delete, change, check.
SQL Primary Action object: Database, table, record.
(Note: The following lab operations are only getting started practiced hand, SQL is far more powerful than these!) ）

2. Database operations

2.1 Create a database. Enter MySQL via phpMyAdmin, click on the SQL button in the left column, for example.

In the pop-up box, enter:CREATE database schooldb; Click Execute.

2.2 Querying the database
　　show databases;

　　
2.3 Deleting a database
　　Drop database schooldb;

　　

show databases;

　　

3. Table Operations
3.1 Creating a Table
　　Create Database schooldb;
Select Schooldb in the left column, and click the SQL button in the right navigation bar , such as. The following actions in the database allow you to open the SQL edit box with this button.

　　
　　CREATE TABLE Student (
ID Int (5) is not NULL,
Name varchar (20),
Birthday Date
);

3.2 Enquiry Form
　　Show tables;
DESC student;

3.3 Change Table
Add column
Delete Column alter table student drop column phone;

3.4 Delete table
drop table student;

4. Record operations
4.1 Creating a Table
　　CREATE TABLE Student (
ID Int (5) is not NULL,
Name varchar (20),
Birthday Date
);
Inserting records
　　INSERT into student values (1, ' Guo Jing ', ' 1990-01-01 ');
INSERT into student values (2, ' Huang Rong ', ' 1992-02-02 ');
INSERT into student values (3, ' Ling Hu ', ' 1993-03-03 ');
INSERT into student values (4, ' Dong Fang ', ' 1994-04-04 ');

4.2 Querying records
　　SELECT * from student;

　　

4.3 Change record
　　Update student set birthday= ' 1993-04-04 ' where Name= ' Dong Fang ';

4.4 Deleting records
　　Delete from student where Name= ' Dong Fang ';

3 MySQL SQL Basics