Your <code>TEXT</code> field contains a string of no characters. This is not the same as a field containing the value <code>NULL</code>. You can, if you like, add a check constraint which says that the field must not be the zero-length string.
Your <code>TEXT</code> field contains a string of no characters. This is not the same as a field containing the value <code>NULL</code>. You can, if you like, add a check constraint which says that the field must not be the zero-length string.