Today has been a very unpleasant day, since I work as a DBA and made changes in production that ended badly due to a huge BUG that HeidiSQL has.
If you have a Primary Key configured with Auto_Increment, and then modify the Data Type, changing it to another type ..
Eg change an INT type to MEDIUMINT
HeidiSQL removes the Auto_Increment as a property of the field and leaves a '0' as the DEFAULT value.
all subsequent INSERTs fail when they detect duplicate key.
(I have tested this on all other tools available on the market and none of them give this fault)
And not only that ... any numerical data that you modify, if it does not have a DEFAULT value assigned ... it forces a '0' which is a very big error.
I thought it was because I had version 10.3, but now with the latest version .. still with the error.
Please correct this .. it is very bad.