Question

I have a table with two DATETIME columns.

One of them is never NULL, but one of them is sometimes NULL.

I need to write a query which will set all the NULL rows for column B equal to the values in column A.

I have tried this example but the SQL in the selected answer does not execute because MySQL Workbench doesn’t seem to like the FROM in the UPDATE.

Answer 1

Sounds like you’re working in just one table so something like this:

update your_table
set B = A
where B is null