How to Add column Value to a Set Variable in Mysql in an Update Statement?

Question

This works:

update my_table set credits_total = credits_total + 1 where id = 4;

But this doesn't:

SET @add_credits = 1;
update my_table set credits_total = credits_total + @add_credits where id = 4;

It's giving me a 'column credits_total cannot be null' error.

What am I doing wrong? Thanks.

Answer 1

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