T-SQL 操作练习

 create table Person #新建表格
 (
     Ids int auto_increment primary key, #主键,自增
     Name varchar(50) not null, #非空
     Age int,
     Sex bit,
     Nation varchar(50) references Nation(Code) #外键
 );
 create table Person_1 #新建表格
 (
     Ids int auto_increment primary key,
     Name varchar(50) not null,
     Age int,
     Sex bit,
     Nation varchar(50) references Nation(Code)
 );
 create table Nation #新建表格
 (
     Code varchar(50) primary key,
     Name varchar(50)
 );

 drop table Person_1;#删除表格

 #增加加数据 insert into 表名[(列)] values(数据.对应,可为空)

 insert into Person values('','张三',18,1,'汉族');
 insert into Person values('','李四',28,2,'回族');
 insert into Person values('','李五',28,2,'回族');
 insert into Person(Name) values('王五');
 insert into Nation values('','汉族');
 insert into Nation values('','回族');

 #删除数据 delete from 表名;删除整个表
 #delete from 表名 where 条件
 #delete form Person where Ids=3;

 #更改数据 update 表名 set 列 = "" where 条件;
 update Person set Name="张八" where Ids=2;
 update Person set Nation="维吾尔族" where Name="王五";

 #查找数据
 select * from Person;
 select * from Nation where Code='';

 delete from Person where name="李五";

 #################################################
 #新建表
 create table Family
 (
     Name varchar(50) not null,
     Number int,
     Code varchar(50) primary key,
     Color varchar(50) references Color(Code)
 );
 create table Color
 (
     Code int auto_increment primary key,
     Name varchar(50)
 );
 #CRUD
 #insert into 表名 values(数据),
 #insert into 表名(列) values(数据),
 insert into Family values('1户',4,'','red');
 insert into Family values('2户',3,'','');
 insert into Family values('4户',3,'','');
 insert into Family(Code) values('');
 insert into Family(Name) values('3户');
 insert into Color values('','red');
 insert into Color values('','blue');
 insert into Color values('','blue');

 #update
 #update Table_Name set Cols_Name='' where Condition
 update Family set Color='white' where Code='';

 #delete
 #delete from Table_Name;
 #delete from Table_Name where Condition;
 delete from Family where Name='4户';
 delete from Color where Code='';

 #select
 #select * from Table_Name;
 #select * from Table_Name where Condition;

 select * from Family ;
 select * from Color where Code=''