SQL: While loop in While Loop - sql

Question

I am trying to insert 10K names in Parent table, Using 10 described names while adding number in the back. But managing to write only first thousand. I need your eyes to see where I am failing. I do understand that #i is not increesing but dont know why.
DECLARE #TempNameTable table (ID int , Name varchar (50))
DECLARE #i int = 1,
#tempNameValue varchar(50),
#randNumber int = 1
INSERT INTO #TempNameTable VALUES
(1,'Jonas'), (2,'Petras'),(3,'Antanas')
, (4,'Stasys'), (5,'Dainius'), (6,'Giedrius')
, (7,'Mindaugas'), (8,'Povilas'), (9,'Kestutis')
, (10,'Darius')
WHILE ((SELECT COUNT(Name) FROM Parent) < 10000)
BEGIN
WHILE #i < 11
BEGIN
SET #tempNameValue = CASE
WHEN #i = 1 THEN
(SELECT Name from #TempNameTable WHERE ID = #i)
WHEN #i = 2 THEN
(SELECT Name from #TempNameTable WHERE ID = #i)
WHEN #i = 3 THEN
(SELECT Name from #TempNameTable WHERE ID = #i)
WHEN #i = 4 THEN
(SELECT Name from #TempNameTable WHERE ID = #i)
WHEN #i = 5 THEN
(SELECT Name from #TempNameTable WHERE ID = #i)
WHEN #i = 6 THEN
(SELECT Name from #TempNameTable WHERE ID = #i)
WHEN #i = 7 THEN
(SELECT Name from #TempNameTable WHERE ID = #i)
END
WHILE #randNumber < 1000
BEGIN
INSERT INTO Parent VALUES
(#tempNameValue + CAST(#randNumber as varchar(1000)))
SET #randNumber = #randNumber + 1
END
SET #i = #i + 1
END
END

Answer 1

I suppose your query becomes:
DECLARE #TempNameTable table (ID int , Name varchar (50))
DECLARE #tempNameValue varchar(50),
#randNumber int = 1
INSERT INTO #TempNameTable VALUES
(1,'Jonas'), (2,'Petras'), (3,'Antanas'),
(4,'Stasys'), (5,'Dainius'), (6,'Giedrius'),
(7,'Mindaugas'), (8,'Povilas'), (9,'Kestutis'), (10,'Darius')
WHILE ((SELECT COUNT(Name) FROM Parent) < 10000)
BEGIN
SET #randNumber = 1
WHILE #randNumber <= 1000
BEGIN
INSERT INTO Parent
SELECT Name + CAST(#randNumber as varchar(1000))
FROM #TempNameTable
SET #randNumber = #randNumber + 1
END
END

Answer 2

I'd do it like the below. Just tested and it outputs each name * 1,000 rows. It's more verbose but its obvious what it's doing and it works.
Declare #Jonas varchar(20) = 'Jonas'
Declare #Petras varchar(20) = 'Petras'
Declare #Antanas varchar(20) = 'Antanas'
Declare #Stasys varchar(20) = 'Stasys'
Declare #Dainius varchar(20) = 'Dainius'
Declare #Giedrius varchar(20) = 'Giedrius'
Declare #Mindaugas varchar(20) = 'Mindaugas'
Declare #Povilas varchar(20) = 'Povilas'
Declare #Kestutis varchar(20) = 'Kestutis'
Declare #Darius varchar(20) = 'Darius'
Declare #TempJonas varchar(20)
Declare #TempPetras varchar(20)
Declare #TempAntanas varchar(20)
Declare #TempStasys varchar(20)
Declare #TempDainius varchar(20)
Declare #TempGiedrius varchar(20)
Declare #TempMindaugas varchar(20)
Declare #TempPovilas varchar(20)
Declare #TempKestutis varchar(20)
Declare #TempDarius varchar(20)
Declare #NameIncrement int = 0
WHILE #NameIncrement <= 1000
BEGIN
Set #TempJonas = #Jonas + CONVERT(varchar(6),#NameIncrement)
Set #TempPetras = #Petras + CONVERT(varchar(6),#NameIncrement)
Set #TempAntanas = #Antanas + CONVERT(varchar(6),#NameIncrement)
Set #TempStasys = #Stasys + CONVERT(varchar(6),#NameIncrement)
Set #TempDainius = #Dainius + CONVERT(varchar(6),#NameIncrement)
Set #TempGiedrius = #Giedrius + CONVERT(varchar(6),#NameIncrement)
Set #TempMindaugas = #Mindaugas + CONVERT(varchar(6),#NameIncrement)
Set #TempPovilas = #Povilas + CONVERT(varchar(6),#NameIncrement)
Set #TempKestutis = #Kestutis + CONVERT(varchar(6),#NameIncrement)
Set #TempDarius = #Darius + CONVERT(varchar(6),#NameIncrement)
Insert Into Parent
Select #TempJonas
Insert Into Parent
Select #TempPetras
Insert Into Parent
Select #TempAntanas
Insert Into Parent
Select #TempStasys
Insert Into Parent
Select #TempDainius
Insert Into Parent
Select #TempGiedrius
Insert Into Parent
Select #TempMindaugas
Insert Into Parent
Select #TempPovilas
Insert Into Parent
Select #TempKestutis
Insert Into Parent
Select #TempDainius
Set #NameIncrement = #NameIncrement + 1
END

Answer 3

Set based answer without loops:
rextester: http://rextester.com/EBM78452
declare #TempNameTable table (id int , Name varchar (50))
insert into #TempNameTable values
(1,'Jonas'), (2,'Petras'), (3,'Antanas')
, (4,'Stasys'), (5,'Dainius'), (6,'Giedrius')
, (7,'Mindaugas'), (8,'Povilas'), (9,'Kestutis')
, (10,'Darius');
if object_id('tempdb..#r') is not null drop table #r;
create table #r (n int not null primary key, r int not null);
with n as (select n from (values(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) t(n))
, d as (
select n=row_number() over (order by (select 1))
, r=convert(int,((rand(checksum(newid())) * 10)+1))
from n as deka
cross join n as hecto
cross join n as kilo
cross join n as tenK
)
insert into #r (n, r)
select n, r from d;
--insert into Parent
select Name=Name+convert(varchar(13),n)
from #r as r
inner join #TempNameTable t on r.r=t.id
This uses convert(int,((rand(checksum(newid())) * 10)+1)) to generate a random number from 1 to 10, and uses that to join the temp table #r to #TempNameTable