数据库的操作笔记

MySQL的常见操作在这里先做一下总结，已经整合到代码里面，经过检验无误。

/*创建一个数据库*/create database xuning_test;/*说明当时使用数据库对象*/use xuning_test;/*向数据库中添加表并且定义表的结构*/create table person(id int not null,name varchar(16) not null,sex varchar(16) not null,age int not null,address varchar(128) not null,remark varchar(512) not null);/*向数据库的表中插入数据*/insert into person value(1,'name_1','men',99,'beijing','This is a frindsheep boy'),(2,'name_2','men',88,'shanghai','ok great'),(1,'name_3','man',77,'guangzhou','This is lickly'),(1,'name_4','men',66,'beijing','This is a frindsheep boy'),(1,'name_5','men',55,'beijing','you dont going to shool'),(1,'name_6','man',44,'beijing','This is a frindsheep boy'),(1,'name_7','men',33,'beijing','This is a frindsheep boy'),(1,'name_8','man',22,'beijing',''),(1,'name_9','men',11,'beijing','This is a frindsheep boy');/*查询时否成功插入*/select * from person;/*下面是多种查询方式*//*根据列的名称属性值*/select name from person;/*添加条件-根据性别*/select name from person where sex = 'men';/*也可以用比较符作为条件--一定逗号隔开*/select name,address from person where age > 50;/*看做对象去使用数据库和表的关系=---双表关联--对象关系一定要明确*/select xuning_test.person.name, xuning_test.person.id, xuning_test.person.age, xuning_test.person.addressfrom xuning_test.person, test1.test_xuningwhere xuning_test.person.id = test1.test_xuning.id;/*使用表的别名进行查询*/use xuning_test;select c.name,sex from person as c where c.age > 40 and c.address='beijing';