CREATE TABLE #T4 (Client_net varchar(80), loyalty varchar(80))
DECLARE @cntr int, @n int, @n1 int, @n2 int, @n3 int, @client_net varchar(80), @client_net2 varchar(80), @client_net3 varchar(80), @Datestr varchar(80)
DECLARE Date_Cursor SCROLL CURSOR FOR
SELECT #Temp3.art_month, #Temp3.clent_net
FROM #Temp3
Where #Temp3.clent_net LIKE '%Атлант%' OR #Temp3.clent_net LIKE '%Варяг%' OR #Temp3.clent_net LIKE '%Хознужды%'
Group BY #Temp3.art_month, #Temp3.clent_net
ORDER BY  #Temp3.clent_net, #Temp3.art_month DESC
OPEN Date_Cursor
FETCH NEXT FROM Date_Cursor
into @n2, @client_net2 
WHILE @@FETCH_STATUS = 0
BEGIN
IF @client_net2 = @client_net 
BEGIN
SET @n = @n2 - @n1
SET @Datestr=
CASE WHEN @n = 1 THEN
@Datestr+'1'
 WHEN @n = 2 THEN
@Datestr+'01'
 WHEN @n = 3 THEN
@Datestr+'001'
 WHEN @n = 4 THEN
@Datestr+'0001'
 WHEN @n = 5 THEN
@Datestr+'00001'
 WHEN @n = 6 THEN
@Datestr+'000001'
 WHEN @n = 7 THEN
@Datestr+'0000001'
 WHEN @n = 8 THEN
@Datestr+'00000001'
 WHEN @n = 9 THEN
@Datestr+'000000001'
 WHEN @n = 10 THEN
@Datestr+'0000000001'
 WHEN @n = 11 THEN
@Datestr+'00000000001'
 WHEN @n = 12 THEN
@Datestr+'000000000001'
ELSE @Datestr
END
PRINT @n
PRINT @Datestr
end
ELSE
begin
PRINT @Datestr
INSERT INTO #t4 (Client_net, loyalty) VALUES (@client_net2, @Datestr)
Set @Datestr ='0'
end

SET @Datestr = @Datestr + right(''000000000001', @n)

CREATE TABLE #T4 (Client_net varchar(80), loyalty varchar(80))
DECLARE @cntr int, @n int, @n1 int, @n2 int, @n3 int, @client_net varchar(80), @client_net2 varchar(80), @client_net3 varchar(80), @Datestr varchar(80)
DECLARE Date_Cursor SCROLL CURSOR FOR
SELECT #Temp3.art_month, #Temp3.clent_net
FROM #Temp3
Where #Temp3.clent_net LIKE '%Атлант%' OR #Temp3.clent_net LIKE '%Варяг%' OR #Temp3.clent_net LIKE '%Хознужды%'
Group BY #Temp3.art_month, #Temp3.clent_net
ORDER BY  #Temp3.clent_net, #Temp3.art_month DESC
OPEN Date_Cursor
FETCH NEXT FROM Date_Cursor
into @n2, @client_net2 
WHILE @@FETCH_STATUS = 0
BEGIN
IF @client_net2 = @client_net 
BEGIN
SET @n = @n2 - @n1
SET @Datestr=  @Datestr + right('000000000001', @n)

PRINT @n
PRINT @Datestr
end
ELSE
begin
PRINT @Datestr
INSERT INTO #t4 (Client_net, loyalty) VALUES (@client_net2, @Datestr)
Set @Datestr ='0'
end

FETCH NEXT FROM Date_Cursor
FETCH PRIOR FROM Date_Cursor
into @n2, @client_net2 
PRINT @client_net2
IF @@Fetch_Status = 0
Begin
FETCH NEXT FROM Date_Cursor
into @n1, @client_net 



End
END

CLOSE Date_Cursor
DEALLOCATE Date_Cursor 

declare @t table(art_month int, clent_net varchar(16))

insert @t values( 1, 'Атлант')
insert @t values( 3, 'Атлант')
insert @t values( 7, 'Атлант')
insert @t values( 3, 'Варяг')
insert @t values( 7, 'Варяг')
insert @t values( 11,'Варяг')
insert @t values( 11,'Варяг')
insert @t values( 7, 'Хознужды')
insert @t values( 3, 'Хознужды')
insert @t values( 7, 'Хознужды')
insert @t values( 11,'Хознужды')
insert @t values( 12,'Хознужды')

;with
myselect as ( SELECT art_month, clent_net
                      FROM @t
                      Where clent_net LIKE '%Атлант%' OR clent_net LIKE '%Варяг%' OR clent_net LIKE '%Хознужды%'
)
,
clients as ( select DISTINCT clent_net  FROM myselect )
,
months as (                               select 1 month
                                   union all select 2
                                   union all select 3
                                   union all select 4
                                   union all select 5
                                   union all select 6
                                   union all select 7
                                   union all select 8
                                   union all select 9
                                   union all select 10
                                   union all select 11
                                   union all select 12
                  )
,
-- вам чо, для каждого клиента clent_net поставить в строчке из 12 нулей '000000000000'
-- единички на место месяцев, которые есть в выборке myselect для клиента?
[01] as (select c.clent_net, m.month
                  , case 
                       when exists(select * from myselect s where s.clent_net = c.clent_net and s.art_month = m.month ) then '1'
                       else '0'
                    end [01]
              from clients c cross join months m
          )

select c.clent_net
       , replace( (select [01] as [data()] from [01] where c.clent_net = [01].clent_net order by [01].month for xml path('')), ' ','')
  from clients c

;with 
client as (select * from (values(1,'Атлант'),(2,'Варяг'),(3,'Хознужды'))tmp(id,name)),
sales as (select * from (values
	(1,1),(2,1),(7,1),
	(3,2),(7,2),(11,2),(12,2),
	(7,3),(8,3),(9,3),(11,3),(12,3),
	(2,1),(7,2),(2,1),(9,3),(7,3)
	)tmp(month,client))
-- рассчитать лояльность клиента в виде:
-- клиент, месяц первой продажи, число месяцев с ежемесячными продажами
-- т.е. получить: (1,1,2),(1,7,1),(2,3,1),(2,7,1),(2,11,2),(3,7,3),(3,11,2)
----------select c.name, s.month
----------	from sales s 
----------	join client c on c.id=s.client
----------	order by c.name, s.month
,recurs as (
	select distinct s.client,s.month, s.month last, 1 loyal
		from sales s
		left join sales p on p.client=s.client and p.month=s.month-1
		where p.month is null
	union all
	select r.client, r.month, s.month, r.loyal+1
		from recurs r
		join sales s on s.client=r.client and s.month=r.last+1
	)
,loyal as (
	select distinct *, max(loyal) OVER (PARTITION BY client,month) loyality
		from recurs r
	) 
select l.client, c.name, l.month, l.loyality
	from loyal l
	join client c on c.id=l.client
	where l.loyal=l.loyality
	order by l.loyality desc, l.month desc, l.client

client      name     month       loyality
----------- -------- ----------- -----------
3           Хознужды 7           3
2           Варяг    11          2
3           Хознужды 11          2
1           Атлант   1           2
1           Атлант   7           1
2           Варяг    7           1
2           Варяг    3           1

set nocount on
declare @t table(month int, client varchar(16))

insert @t values( 1, 'Атлант')
insert @t values( 3, 'Атлант')
insert @t values( 4, 'Атлант')
insert @t values( 5, 'Атлант')
insert @t values( 7, 'Атлант')
insert @t values( 3, 'Варяг')
insert @t values( 7, 'Варяг')
insert @t values( 10,'Варяг')
insert @t values( 11,'Варяг')
insert @t values( 11,'Варяг')
insert @t values( 7, 'Хознужды')
insert @t values( 3, 'Хознужды')
insert @t values( 7, 'Хознужды')
insert @t values( 11,'Хознужды')
insert @t values( 12,'Хознужды')

declare @ibeg table (n int identity, client varchar(16), month int, primary key clustered(client, month))
declare @iend table (n int identity, client varchar(16), month int, primary key clustered(client, month))

-- начала интервалов непрерывности
insert @ibeg (client, month )
select DISTINCT client, month
from @t T where not exists(select * from @t X where X.client = T.client and X.month=T.month-1)
order by client, month

select * from @ibeg

-- Концы интервалов непрерывности
insert @iend (client, month )
select DISTINCT client, month
from @t T where not exists(select * from @t X where X.client = T.client and X.month=T.month+1)
order by client, month

select * from @iend

-- интервалы
declare @i table (i int identity, client varchar(16), monthB int, monthE int, length int, primary key clustered(client, monthB))
insert @i(client, monthB, monthE, length )
select b.client, b.month, e.month, e.month-b.month+1
from @ibeg b inner join @iend e on b.client=e.client and b.n=e.n
order by b.client, b.month

select * from @i

-- максимальные интервалы
select *
from @i i 
where i.length = (select max(j.length) from @i j where j.client = i.client)

year(@date)*100+month(@date)

select right(@month,2)+'.'+left(@month,4)

declare @ibeg table (n int identity, clent_net varchar(80), art_month int primary key clustered(clent_net, art_month))
declare @iend table (n int identity, clent_net varchar(80), art_month int primary key clustered(clent_net, art_month))

-- начала интервалов непрерывности
insert @ibeg (clent_net, art_month)
select DISTINCT clent_net, art_month
from #Temp3 T where not exists(select * from #Temp3 X where X.clent_net = T.clent_net and X.art_month=T.art_month-1)
order by clent_net, art_month

select * from @ibeg <---- Вот в этом месте выскакивает ошибка Violation of PRIMARY KEY constraint 'PK__@ibeg__3CE3C0EF'. Cannot insert duplicate key in object '#3BEF9CB6'.
The statement has been terminated.

declare @ibeg table (n int identity, clent_net varchar(512), art_month int
, primary key clustered(clent_net, art_month))

year(@date)*100+month(@date)

right(101+yymm%12,2)+'.'+cast(yymm%12 as varchar(5))