Want to pseudo column is used to implement the following function, but found no direct pseudo column MySQL function,,,

Topic: check which service has the highest HuoJiangShu,

Data dictionary:

The Sales, after-sales service table)
Salesno int after-sales service number;
Sname varchar after-sales service projects;

The Client (the customer table)
Clientno int customer number;
Cname varchar customer name;
Empno int employee number;
The Age int Age;
Ctele varchar customer calls;
Houseno varchar number;
Sex varchar Sex;
Goodsno varchar prize number;
Salesno int after-sales service number;

The customer information table:

After-sales service table:


Kindly bosses, help me take a look at this how to write, and the pseudo column does need to use,,,

CodePudding user response:

This is your initial idea,,, (not finish)

CodePudding user response:

SELECT * FROM (

SELECT s.s name, COUNT (*) as the FROM CNT sales s LEFT JOIN client c ON s.s alesno=c.s. alesno GROUP BY s.s alesno

B) as the ORDER BY CNT desc
Limit 1;
Has been solved, need not trouble bosses,,,

CodePudding user response:

Holiday also in work, good!

CodePudding user response:

big brother, I also read undergraduate course,,, this is your final project,,,

CodePudding user response:

big brother, I also read undergraduate course,,, this is your final project,,,