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.
Someone with red spots on their tongue may be suffering from geographic tongue, according to Mayo Clinic. Other causes of red spots on the tongue include folic acid and vitamin B-12 deficiencies and scarlet fever, WebMD states. Continue Reading.
1. Leukoplakia. This is a condition that causes excessive growth of cells in the mouth hence leading to the formation of white patches in the mouth, on the lips, gums, tongue, inside cheeks and on the floor or roof of the mouth.