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.
Median rhomboid glossitis is a condition that can affect your tongue if you have oral thrush. It causes a red, smooth patch or lump to develop in the middle of the top part of your tongue, which can be sore. You're more likely to develop oral thrush if you: have recently taken antibiotics.
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.