You can use logical functions in custom tables and fields. See Adding a New Custom Table and Defining and Editing Field Formula for further details. Below are explanations of available logical functions.

IFBIGINT(condition, true value, false value)
Returns the first value if the boolean evaluate is true, else returns the second value.

IFDATETIME(condition, true value, false value)
Returns the first value if the boolean evaluate is true, else returns the second value.

IFDOUBLE(condition, true value, false value)
Returns the first value if the boolean evaluate is true, else returns the second value.

IFINT(condition, true value, false value)
Returns the first value if the boolean evaluate is true, else returns the second value.

IFSTRING(condition, true value, false value)
Returns the first value if the boolean evaluate is true, else returns the second value.

INRANGE(value,start,end)
Returns true if a given value is between start and end.

ISNULL(value)
Returns true if a given value is null.