When one column of data is added to mysql, the error Datatruncatedforcolumn 'tg _ level' atrow1 is returned.

When mysql adds a new column of data, the error Datatruncatedforcolumn 'tg _ level' atrow1 is inserted with this column altertabletg_userchangetg_leveltg_leveltinyint (1) the error "Data truncated for column 'tg _ level' at row 1" is returned when unsignedno is added to mysql.
Insert the alter table tg_user change tg_level tinyint (1) unsigned not null column. Please help me

------ Solution --------------------
It's not update, it's add, so it's strange that the root cause is not found.

Discussion

Delete the original data in the database, because the original data is set to not null, which is in conflict.