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.
White tongue: White spots, patches or coating of the tongue. See detailed information below for a list of 29 causes of White tongue, Symptom Checker, including diseases and drug side effect causes.Â» Review Causes of White tongue: Causes | Symptom Checker Â».he following medical conditions are some of the possible causes of White tongue. There are likely to be other possible causes, so ask your doctor about your symptoms. 1  Oral candidiasis. 2  Candidiasis. 3  Leukoplakia-white tongue or mouth lining. 4  Keratosis pharyngis-usually white lumps on the tonsils.