Day06 homework - skill question 7

1. establish db_test database

create database db_test character set utf8;

2. establish yuangong surface

create table yuangong(
empno int not null primary key,
ename varchar(50),
job varchar(50),
mgr int,
hiredate date,
sal decimal(7,2),
COMM decimal(7,2),
deptno int
)
desc yuangong;

3. towards yuangong Add records to the table

insert into yuangong value 
(1001,' Gan Ning ',' Clerk ',1013,'2000-12-17',8000.00,null,20),
(1002,' Daisy ',' Salesperson ',1006,'2001-02-20',16000.00,3000.00,30),
(1003,' Yin Zhengtian ',' Salesperson ',1006,'2001-02-22',12500.00,5000.00,30),
(1004,' Liu bei ',' The manager ',1009,'2001-04-02',29750.00,null,20),
(1005,' Thank sun ',' Salesperson ',1006,'2001-09-28',12500.00,14000.00,30),
(1006,' Guan yu ',' The manager ',1009,'2001-05-01',28500.00,null,30),
(1007,' Zhang Fei ',' The manager ',1009,'2001-09-01',24500.00,null,10),
(1008,' Zhugeliang ',' analysts ',1004,'2007-04-19',30000.00,null,20),
(1009,' Zeng a Niu ',' Chairman of the board of directors ',null,'2001-11-17',50000.00,null,10),
(1010," Xiangr "," Salesperson ",1006,"2001-09-08",15000.00,0.00,30),
(1011," Zhou Tai "," Clerk ",1008,"2007-05-23",11000.00,null,20),
(1012," Cheng pu "," Clerk ",1006,"2001-12-03",9500.00,null,30),
(1013," Pang Tong "," analysts ",1004,"2001-12-03",30000.00,null,20),
(1014," Huang Gai "," Clerk ",1007,"2002-01-23",13000.00,null,10),
(1015," Zhang San "," Clerk ",1007,"2002-01-23",53000.00,null,50)

Use sql Statement completes the following functions ：

(1) Look up everything in the table

select * from student;

 

(2) Change the table name to ”emp”

alter table yuangong rename emp;

(3) modify ename The type of field is varchar(40)

alter table emp MODIFY COLUMN ename varchar(40);
desc emp;

(4) Delete... From the table empno yes 1014 also ename It's Huang Gai's employee information

delete from emp where empno=1014 and ename=' Huang Gai ';
select * from emp;

(5) In the query table empno The value of the field is 1007,1009 or 1011 All records of employees

select * from emp where empno in(1007,1009,1011);

(6) Query all in the table job All the information of the employee whose field is clerk and whose name is Zhang San

select * from emp where job=' Clerk ' and ename=' Zhang San ';

(7) Query table in 2001 Information of employees who have been employed since

select * from emp where hiredate >'2001-12-31';