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.
Also Read: How to get rid of sharp pain in tongue . Causes of blister on tongue. Blisters on the tongue are as a result of wide range of causes. They are named depending on the area of the tongue they affect and the time they may take to clear. The following are some of the many causes of blisters on the tongue: 1. Sexually Transmitted Diseases [STD]