The usual logical operators are available: AND, OR, NOT

SQL uses a three-valued Boolean logic where the null value represents "unknown". Observe the following truth tables:

Table 3-14 AND/OR Truth Table

a	b	a AND b	a OR b
True	True	True	True
True	False	False	True
True	Null	Null	True
False	False	False	False
False	Null	False	Null
Null	Null	Null	Null

Table 3-15 NOT Truth Table

a	NOT a
True	False
False	True
Null	Null

The operators AND and OR are commutative, that is, you can switch the left and right operand without affecting the result.