SQL Insert iterative number and Id of select Table 1 into table2 - sql

Question

I have a numeric sequence of items that I need to insert into an entire table [Table 2].
Table 2 is made of items related to Table 1.
I need to add a set number of elements (A SET of ITEMS) into Table 2 , each set for each ID of Table 1. ID 1 in Table 1 will have roughly 100 elements referenced in Table 2 items 1-99, 100-199 would be associated with ID 2.
That might not be as clear as the pseudo code below. That is what I am trying to achieve.
Pseudo Code is
For Each Record in Select All Records from Table 1 ***(this is where I need help to know how to do)***
SET #cnt=1;
While (#cnt <100)
Insert Into Table 2, PK=#cnt, Name_#Cnt, Record.Id
SET #cnt =#cnt+1;
End
Maybe there is an easier way - by creating a temp table and insert on Innerjoin ??
I do not know I am rustier than I would like to be..

Answer 1

On the latest version of SQL Server, this is simply a case of using GENERATE_SERIES:
INSERT INTO dbo.Table2 (<Column List>)
SELECT <T1 Column List>,
GS.Value
FROM dbo.Table1 T1
CROSS APPLY GENERATE_SERIES(1,100,1);
On older versions, then you'll want to use a Tally. Ideally you'll want to create a function, but you can do this inline:
WITH N AS (
SELECT N
FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL))N(N)),
Tally AS (
SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS I
FROM N N1, N N2) --100 rows
INSERT INTO dbo.Table2 (<Column List>)
SELECT <T1 Column List>,
T.I
FROM dbo.Table1 T1
CROSS JOIN Tally T;
If you wanted to create a function, then the one I use is the following:
CREATE FUNCTION fn.Tally (#End bigint, #StartAtOne bit)
RETURNS table
AS RETURN
WITH N AS(
SELECT N
FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL))N(N)),
Tally AS(
SELECT 0 AS I
WHERE #StartAtOne = 0
UNION ALL
SELECT TOP (#End)
ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS I
FROM N N1, N N2, N N3, N N4, N N5, N N6, N N7, N N8)
SELECT I
FROM Tally;
Then you could use that in your INSERT in a similar way to GENERATE_SERIES:
INSERT INTO dbo.Table2 (<Column List>)
SELECT <T1 Column List>,
T.I
FROM dbo.Table1 T1
CROSS APPLY fn.Tally(100,1);