CREATE TABLE A(ID nvarchar(10),PR nvarchar(10),Material nvarchar(10),Panel  nvarchar(20), QTY int, SerialID nvarchar(10),Serial varchar(50),PanelNo varchar(20))
INSERT INTO A(ID,PR,Material,Panel,QTY) VALUES('S001', 'P001','M1','H1,H2,H3',3)
INSERT INTO A(ID,PR,Material,Panel,QTY) VALUES('S002', 'P002','M3','AH2,AH5',4)
INSERT INTO A(ID,PR,Material,Panel,QTY) VALUES('S003', 'P001','M6','P01,P03',2)
INSERT INTO A(ID,PR,Material,Panel,QTY) VALUES('S004', 'P002','M5','AH3',1)
INSERT INTO A(ID,PR,Material,Panel,QTY) VALUES('S005', 'P006','M8','PA1,PA2',2)
GO

--如果只是查询：
declare @sql varchar(8000)
set @sql=''
select @sql=@sql+replace(Panel+',',',','''p,'''+id+'''d union all select ''') from a where QTY<>4
set @sql='select '''+@sql
set @sql=left(@sql,len(@sql)-19)
exec('select id,pr,Material,Panel,[Qty]=case qty when 4 then 4 else 1 end,pr+''-''+Material+''-''+p[Serial],p[PanelNo]
 from a left join ('+@sql+')b on id=d') 

--> 测试数据: #T
if object_id('tempdb.dbo.#T') is not null drop table #T
create table #T (ID varchar(4),PR varchar(4),Material varchar(2),Panel varchar(10),QTY int,Serial varchar(50),PanelNo varchar(50))
insert into #T
select 'S001','P001','M1','H1,H2,H3',3,null,null union all
select 'S002','P002','M3','AH2,AH5',4,null,null union all
select 'S003','P001','M6','P01,P03',2,null,null union all
select 'S004','P002','M5','AH3',1,null,null union all
select 'S005','P006','M8','PA1,PA2',2,null,null

;
with
    T (ID,P1,P2) as
    (
        select ID,charindex(',',','+Panel),charindex(',',Panel+',')+1 from #T where len(Panel)-len(replace(Panel,',',''))+1=Qty
        union all
        select a.ID,b.P2,charindex(',',Panel+',',b.P2)+1 from #T a join T b on a.ID=b.ID where charindex(',',Panel+',',b.P2) > 0
    ),
    P as
    (
        select a.ID,Panel=substring(a.Panel+',',b.P1,b.P2-b.P1-1),Qty=1 from #T a join T b on a.ID=b.ID
    )
select
    a.ID,
    a.PR,
    a.Material,
    a.Panel,
    Qty=isnull(b.QTY,a.Qty),
    Serial=isnull(a.PR+'-'+a.Material+'-'+b.Panel,''),
    PanelNo=isnull(b.Panel,'')
from
    #T a left join P b on a.ID=b.ID

/*
ID     PR     Material     Panel        QTY     Serial       PanelNo 
S001   P001    M1         H1,H2,H3       1      P001-M1-H1     H1 
S001   P001    M1         H1,H2,H3       1      P001-M1-H2     H2 
S001   P001    M1         H1,H2,H3       1      P001-M1-H3     H3 
S002   P002    M3         AH2,AH5        4 
S003   P001    M6         P01,P03        1      P001-M6-P01    P01 
S003   P001    M6         P01,P03        1      P001-M6-P03    P03 
S004   P002    M5         AH3            1      P002-M5-AH3    AH3 
S005   P006    M8         PA1,PA2        1      P006-M8-PA1    PA1 
S005   P006    M8         PA1,PA2        1      P006-M8-PA2    PA2 
*/

--> 测试数据: #T
if object_id('tempdb.dbo.#T') is not null drop table #T
create table #T (ID varchar(4),PR varchar(4),Material varchar(2),Panel varchar(10),QTY int,Serial varchar(50),PanelNo varchar(50))
insert into #T
select 'S001','P001','M1','H1,H2,H3',3,null,null union all
select 'S002','P002','M3','AH2,AH5',4,null,null union all
select 'S003','P001','M6','P01,P03',2,null,null union all
select 'S004','P002','M5','AH3',1,null,null union all
select 'S005','P006','M8','PA1,PA2',2,null,null

--> 4楼的是2005写法，下面这个适用2000

if object_id('tempdb.dbo.#') is not null drop table #
select top 100 ID=identity(int,1,1) into # from syscolumns,sysobjects --> select max(len(Panel)) from #T=11
if object_id('tempdb.dbo.#P') is not null drop table #P
select a.ID,Panel=substring(a.Panel+',',b.ID,charindex(',',a.Panel+',',b.ID+1)-b.ID),Qty=1 into #P from #T a inner join # b on substring(','+a.Panel,b.ID,1)=',' where len(a.Panel)-len(replace(a.Panel,',',''))+1=a.Qty

select
    a.ID,
    a.PR,
    a.Material,
    a.Panel,
    Qty=isnull(b.QTY,a.Qty),
    Serial=isnull(a.PR+'-'+a.Material+'-'+b.Panel,''),
    PanelNo=isnull(b.Panel,'')
from
    #T a left join #P b on a.ID=b.ID

/*
ID     PR     Material     Panel        QTY     Serial       PanelNo 
S001   P001    M1         H1,H2,H3       1      P001-M1-H1     H1 
S001   P001    M1         H1,H2,H3       1      P001-M1-H2     H2 
S001   P001    M1         H1,H2,H3       1      P001-M1-H3     H3 
S002   P002    M3         AH2,AH5        4 
S003   P001    M6         P01,P03        1      P001-M6-P01    P01 
S003   P001    M6         P01,P03        1      P001-M6-P03    P03 
S004   P002    M5         AH3            1      P002-M5-AH3    AH3 
S005   P006    M8         PA1,PA2        1      P006-M8-PA1    PA1 
S005   P006    M8         PA1,PA2        1      P006-M8-PA2    PA2 
*/

drop table ass
CREATE TABLE Ass(ID nvarchar(10),PR nvarchar(10),Material nvarchar(10),Panel  nvarchar(20), QTY int, Serial varchar(50),PanelNo varchar(20))
INSERT INTO Ass(ID,PR,Material,Panel,QTY) VALUES('S001', 'P001','M1','H1,H2,H3',3)
INSERT INTO Ass(ID,PR,Material,Panel,QTY) VALUES('S002', 'P002','M3','AH2,AH5',4)

INSERT INTO Ass(ID,PR,Material,Panel,QTY) VALUES('S003', 'P001','M6','P01,P03',2)
INSERT INTO Ass(ID,PR,Material,Panel,QTY) VALUES('S005', 'P006','M8','PA1,PA2',2)

INSERT INTO Ass(ID,PR,Material,Panel,QTY) VALUES('S004', 'P002','M5','AH3',1)
drop table ass
if object_id('xxx') is not null
drop proc xxx

Create proc xxx
as
Begin
  declare @tt  table(ID nvarchar(10),PR nvarchar(10),Material nvarchar(10),Panel  nvarchar(20), QTY int, Serial varchar(50),PanelNo varchar(20))
  declare @ID nvarchar(10)
  declare @PR nvarchar(10)
  declare @Material nvarchar(10)
  declare @Panel  nvarchar(20)
  declare @QTY int
  declare @t int
  declare @Panel2 nvarchar(20)
  declare @Panel3 nvarchar(20)
  set @t=1
  declare cur cursor for select ID, PR,Material,Panel,QTY  from ass  
  open cur 
  fetch cur into @ID,@PR,@Material,@Panel,@QTY
  while  @@fetch_status=0 
    Begin
       if (charindex(',',@Panel)>0) 
           Begin
              if (len(@Panel)-len(replace(@Panel,',',''))+1)=@QTY
                 Begin
                    set @Panel2=@Panel
                    while @t<=@QTY
                       Begin
                           --漏洞判断最后一次
                           if charindex(',',@Panel)>0
                               set @Panel3=Substring(@Panel,1,Charindex(