The result of the above SQL statement will be the number 3, because the customer Smith has made 3 orders in total. If you don't specify a WHERE clause when using COUNT, your statement will simply return the total number of rows in the table, which in our case is 7:
Uses of Sleep Spindles Edit. Sleep spindles are one of several measures employed by the brain to keep a sleeper in an unconscious state. This pattern is produced during sleep to inhibit the processing of unnecessary information, which would especially interrupt stage 2 sleep.
Sleep spindle activity has furthermore been found to be associated with the integration of new information into existing knowledge as well as directed remembering and forgetting (fast sleep spindles). During NREM sleep, the brain waves produced by people with schizophrenia lack the normal pattern of slow and fast spindles. Loss of sleep spindles are also a feature of familial fatal insomnia, a prion disease. Changes in spindle density are observed in disorders such as epilepsy and autism. Gender Differences