MySQL 9th job - connection Query & sub query

1. Inquire about “Chisel” Workshop number of the workshop 、 Name of workshop director 、 Contact information of the director    
2. select no,name,phone from lingjinzheng_workshop where no in(select
   shop_no from zhongzheng_worker where name=“Chisel”);

 

Query the names of all employees 、 Employee contact number 、 Workshop address 、 Name of workshop director 、 Contact information of the director

 select z.name,z.phone,x.address,x.name,x.phone from lingjinzheng_worker
z right join lingjinzheng_workshop x on z.shop_no=x.no;

 

Inquire about “Chisel” Names of all employees in the workshop 、 Employee contact number 、 Workshop address
select z.name,z.phone,x.address from lngjinzheng_worker z inner join
lingjinzheng_workshop x on z.shop_no=x.no where z.shop_no=“WS1”;

  Query the product number of products with qualified quality 、 Employee name 、 Employee contact number
select z.no,x.name,x.phone from lingjinzheng_product z inner join
lingjinzheng_worker x on z.work_no=x.no where is_qualified=“1”

1. Query the workshop number of the workshop where the products have been produced 、 Average length of service

select shop_no ,avg(seniority) from lingjinzheng_worker where
shop_no=“WS2”;

 

Check the product number of all products 、 Qualified or not （ Qualified return true Unqualified return false）、 Employee number 、 Employee name 、 Employee contact information 、 Workshop number 、 Workshop address
select z.no,z.is_qualified,a.no,a.name,a.phone,b.no,b.address from
linjinzheng_product z inner join lingjinzheng_worker a on z.work_no=a.no
inner join lingjinzheng_workshop b on a.shop_no=b.no;

 

1. Query whether there exists in the employee table “common” Employees of the type of work , If it exists, query the employee table “common” All field information of employees of the type of work

select * from lingjinzheng_worker where work_type=“common”;

 

Query the workshop number of resigned employees 、 Workshop director 、 Contact information of the director
select no,name,phone from lingjinzheng_workshop where no in(select
shop_no from lingjinzheng_worker where is_onwork=“0”);