Table entry was reset after "commit work"

Hi,

I met a problem: in my function, I update an entry in a table by using:

update zs_aa set filed_a = value_a where field_b = value_b.

commit work.

when I do debugging, I found the table can be updated after processing first statement. But after running "commit work", the entry was reset to original.

Do you know the reason?

Thanks and Best regards,

Long