The SQL NULL is the term used to represent a missing value. A NULL value in a table is a value in a field that appears to be blank. A field with a NULL value is a field with no value. It is very important to understand that a NULL value is different than a zero value or a field that contains spaces.
spot under tongue pierce. Secondly, tongue piercing is another cause of dark spots on tongue and lips. After the tongue piercing has healed, a dark spot is left on the tongue. The piercing also can lead to dark spot on tongue symptoms because the practice promotes fungal infections. More so, at pierce point, normal tongue pigmentation is lost.
Black hairy or furry tongue or yellow furry tongue: This is caused by dead skin and food buildup, and occurs commonly when the papillae become enlarged, swollen, or rough. When this buildup is paired with bacteria or yeast, it can cause the tongue to look yellow or black and hairy.