Question

我有一个名为Student的表和名为StudentNumber

的字段名称

学生表

StudentNumber
-------------
 1
 2 
 3
 4
 5
 8
 10

期待输出

6
7
9

我试过以下

Declare @trans int;
set @trans = 1;

while(@trans <=50000)
BEGIN
    if((select StudentNumber from [Student] where StudentNumber = @trans) != @trans)
    BEGIN
        print @trans;
    END
END

set @trans = @trans + 1;

Answer 1

试试这个;

declare @id int
declare @maxStudentNumber int

set @id = 1
select @maxStudentNumber = max(StudentNumber) from Student

create table #MissingIds
(
    id int
)

while @id < @maxStudentNumber
begin
    insert into #MissingIds values(@id)
    set @id = @id + 1
end

select m.id 
from #MissingIds m 
left join Student s 
on m.id = s.StudentNumber 
where s.StudentNumber is null

drop table #MissingIds

Answer 2

您可以使用（SQL Server 2016及更高版本）：

SELECT Number
FROM (select cast([key] as int) + 
      (SELECT MIN(StudentNumber) FROM Students) as number 
      from OPENJSON( '[1' 
      + replicate(',1',(SELECT MAX(StudentNumber) FROM Students)-
                       (SELECT MIN(StudentNumber) FROM Students))+']')) n
LEFT JOIN Students s
  ON n.number = s.StudentNumber
WHERE s.StudentNumber IS NULL;

<强> DBFiddle Demo

注意：您可以将第一个子查询与任何其他计数数字生成器交换。更多信息：SQL, Auxiliary table of numbers

Answer 3

应该如下所示

Declare @trans int;
set @trans = 1;

while(@trans <=50000)
BEGIN
if NOT EXISTS (select StudentNumber from [Student] where StudentNumber = @trans)
BEGIN
    print @trans;
END
END

set @trans = @trans + 1;

Answer 4

您可以执行以下操作

;with report as(
   select 1 as missing
   union all
   select missing + 1
   from report
   where missing < @max
)


select *
from report m
where not exists ( select 1 from student s where s.id = m.missing)
option (maxrecursion 0);

这是一个有效的demo

结果

  missing
    6
    7
    9

希望这会对你有所帮助

Answer 5

你可以试试这个：

select m.number from 
(select min(StudentNumber) a,max(StudentNumber) b from Students) c ,master..spt_values M
where c.a <= m.number
and c.b > = m.number
and type ='P'
and m.number not in (select StudentNumber from Students)

如何使用SQL在Sequence字段中查找Missing number？

5 个答案: