sql复习

创建数据库my_tester

CREATE DATABASE my_tester DEFAULT charset utf8;

查看数据库是否创建成功 

SHOW DATABASES;

创建表

CREATE TABLE my_tester (
id INT (10) NOT NULL UNIQUE PRIMARY KEY,
name VARCHAR (20) NOT NULL,
sex VARCHAR (2),
birth YEAR,
address VARCHAR (50),
) ENGINE = INNODB DEFAULT CHARSET = utf8;

根据已有的表my_tester创建新表（复制表）

复制my_tester表结构，创建新表my_tester2

CREATE TABLE my_tester2 LIKE my_tester;

复制my_tester表结构和数据，创建新表my_tester3

CREATE TABLE my_tester3 AS SELECT * FROM my_test

复制my_tester表结构的id,name,sex字段,创建新表my_tester4

CREATE TABLE my_tester4 AS SELECT id, name, sex FROM my_tester WHERE 1 <> 1;