SQL statement-case when then else end, SQL-case

SQL statement-case when then else end, SQL-case

Output the following results based on the preceding table information:

The following are the database and table structure data:

create table DeptSales(deptID int,SubjMonth int ,sales int ,deptname varchar(50))

insert into deptsales (deptid ,subjmonth,sales) values (1,1,55);insert into deptsales (deptid ,subjmonth,sales) values (2,1,66);insert into deptsales (deptid ,subjmonth,sales) values (3,1,77);insert into deptsales (deptid ,subjmonth,sales) values (2,2,34);insert into deptsales (deptid ,subjmonth,sales) values (4,2,56);insert into deptsales (deptid ,subjmonth,sales) values (3,3,78);

Execute the SQL statement:

Mysql> select deptID as 'department ', sum (case SubjMonth when 1 then sales end) 'January sales end', sum (case SubjMonth when 2 then sales end) 'February sales end ', sum (case SubjMonth when 3 then sales end) 'October sales', sum (case SubjMonth when 4 then sales end) 'October sales' from deptsales d group by deptID; + ------ + ------------ + | Department | sales in December | + ------ + ------------ + | 1 | 55 | NULL | 2 | 66 | 34 | NULL | 3 | 77 | NULL | 78 | NULL | 4 | NULL | 56 | NULL | + ------ + ------------ + 4 rows in set

Case whenthenelseend

In case of XXX, if XXX fails, XXX ends.
Case when ...... Then ...... Else ...... End

Case whenthenelseend)

Select ByeTime, case when len (ByeTime)> 0 then str (DATEDIFF (day, ComeInTime, ByeTime) + '(resigned )'
Else str (DATEDIFF (day, ComeInTime, getdate () end as test
From myUser where DelFlag = '0' and UserID = 'cq'
Try this. The syntax should be correct.