A value of NULL indicates that the value is unknown. A value of NULL is different from an empty or zero value. No two null values are equal. Comparisons between two null values, or between a NULL and any other value, return unknown because the value of each NULL is unknown.
Skin Spots on the Face. Most causes of spots on face are harmless. They can be a variety of colors including white, red, black or brown. Common causes include cumulative sun exposure, acne, and skin tags. Keratoacanthoma (hyperkeratosis) is a lesion that grows rapidly, usually on areas exposed to the sun.
If someone who's never had measles complains of cold or flu-like symptoms, looking inside the person's mouth can tell a lot. There are small, red, irregular spots called Koplik's spots that develop on the inside of the cheeks, near the molars. Each spot will have a whitish or bluish centre. Koplik's spots are a sure sign of measles and appear about two days after initial symptoms, which is about 2 days before the rash develops.