Question

I am doing a matrix multiplication project which involves with matrix
So here is my table format:

   create table A ( row integer, col integer, val integer);

What i need to do is to fill in each table with data,
Task 1: create a 200*200 matrix A and all of its element initialized to 1.
That means I would do manually
insert<0,0,1> <0,1,1> <0,2,1> ….<0,199,1>
insert<1,0,1> <1,1,1> <0,2,1> …..<1,199,1> and so

Task 2: create 200*200 matrix A and its diagonal elements are 1’s.

So I am wondering instead of doing this manually, if there anyway to automate initialize all the elements?
The following is an attempt using while loop:

create table A ( row integer, col integer, val integer);
DECLARE @count INT
SET @count = 0
DECLARE @count2 INT
SET @count2 = 0
WHILE (@count < 200)
BEGIN
   WHILE (@count2 <200)
   BEGIN
      INSERT INTO A([row], [col]) VALUES (@count, @counts)
      SET @count2 = (@count2 + 1)
   END
   SET @count = (@count + 1)
END

This the above correct? I am fairly new to sql:(

Answer 1

Avoid loops and iterative stuff. You’re in SQL Server – think set-based

Try this

insert into A( row, col, val )
select row, col, 1
from 
(
        SELECT Row = number from master..spt_values 
        where type='P' and number between 1 and 200
) Rows
CROSS JOIN
(
        SELECT Col = number from master..spt_values 
        where type='P' and number between 1 and 200
) Cols

For your second requirement, you can be lazy and add

where Row = Col

If it’s a one-off thing then this ought to be ok.

The master..spt_values bit is all about getting a range of numbers between 1 and 200. You can also have this variation:

; WITH cte AS
  (
    SELECT n = number  FROM master..spt_values 
    WHERE type = 'P'  AND  number BETWEEN 1 AND 20
  ) 
INSERT INTO A ( row, col, val )
SELECT Rows.n, Cols.n, 1
FROM
    cte AS Rows
  CROSS JOIN
    cte AS Cols ;