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.
NREM Stage 2 (N2 â 45â55% of total sleep in adults): In this stage, theta activity is observed and sleepers become gradually harder to awaken; the alpha waves of the previous stage are interrupted by abrupt activity called sleep spindles (or thalamocortical spindles) and K-complexes.