How do I insert random characters into a sql database column?

Question

I want to populate a column of my database table with 253 lines of 'M' and 'F' randomly placed in the column, is this possible?

Example of what it may look like:

Gender:
M
M
F
M
F
F
M
F
M

Answer 1

For MS SQL you can use NEWID and CHECKSUM functions like:

  UPDATE Users 
  SET Gender = (CASE WHEN ABS(CHECKSUM(NEWID()) % 2) = 1 THEN 'M' ELSE 'F' END)

• NEWID() will generate random GUID

• CHECKSUM() will generate hash of that GUID

• ABS() to make it either 1 or 0

---

WARNING! While some people suggesting to use RAND function - please do not use it for this particular case. The query like this:

UPDATE Users SET Gender = CASE WHEN (RAND() > 0.5) THEN 'M' ELSE 'F' END

.. will result that you have all values either M or either F.

Potentially you can seed RAND function with some value like Id, but distribution of values will be not very good: like first 30-40% all M, then 30-40% all F, then M again.