Logical Operators Logical NOT. Evaluates to  1  if the operand is  0 , to  0  if the operand is nonzero, and  NOT NULL  returns NULL . mysql>  SELECT NOT 10; -> 0 mysql>  SELECT NOT 0; -> 1 mysql>  SELECT NOT NULL; -> NULL mysql>  SELECT ! (1+1); -> 0 mysql>  SELECT ! 1+1; -> 1 The last example produces  1  because the expression evaluates the same way as  (!1)+1 . The  ! , operator is a nonstandard MySQL extension. As of MySQL 8.0.17, this operator is deprecated; expect it to be removed in a future version of MySQL. Applications should be adjusted to use the standard SQL  NOT  operator. Logical AND. Evaluates to  1  if all operands are nonzero and not  NULL , to  0  if one or more operands are 0 , otherwise  NULL  is returned. mysql>  SELECT 1 AND 1; -> 1 mysql>  SELECT 1 AND 0; -> 0 mysql>  SELECT 1 AND NULL; -> NULL mysql>  SELECT 0 AND NULL; -> 0 mysql>  SELECT NULL AND 0; -> 0 The  && , operator is a nonstandard MySQL extension. As of MySQL 8.0.17, this operator is deprecated; expect support for it to be removed in a future version of MySQL. Applications should be adjusted to use the standard SQL  AND  operator. Logical OR. When both operands are non- NULL , the result is  1  if any operand is nonzero, and  0 otherwise. With a  NULL  operand, the result is  1  if the other operand is nonzero, and  NULL  otherwise. If both operands are  NULL , the result is  NULL . mysql>  SELECT 1 OR 1; -> 1 mysql>  SELECT 1 OR 0; -> 1 mysql>  SELECT 0 OR 0; -> 0 mysql>  SELECT 0 OR NULL; -> NULL mysql>  SELECT 1 OR NULL; • NOT ,  ! • AND ,  && • OR ,  || 2132