Question

I need populate with dummy values a table.

I need create a random generated value “RANDOM_VALUE” for every single row created.

Random value must be a string and its range could be only ‘A’ or ‘B’.

The script should be able to list a series of row with value A or B randomly generated

Here an example of how should work:

ROW   RANDOM_VALUE
1     A
2     B
3     B
4     A
...   ...

Any ideas how to do it? Thanks!

Answer 1

Rand() is only evaluated once per column so will be the same for all rows to get around this you can use NewId() as below.

SELECT CHAR(65+ABS(CHECKSUM(NEWID()))%2), RestOfCols
FROM YourTable

If you need the output exactly as per your question just join onto a big enough table. e.g.

WITH cte AS
(
SELECT 
      ROW_NUMBER() OVER (ORDER BY (SELECT 0)) AS ROW,
      CHAR(65+ABS(CHECKSUM(NEWID()))%2) AS RANDOM_VALUE
FROM sys.objects
)
INSERT INTO DummyTable
SELECT ROW,RANDOM_VALUE 
FROM cte 
WHERE ROW<= 4