WHERE clause supports = , > , < , >=, <= predicates and IN ( value1,value2…,valueN ) & LIKE. it also supports AND, OR and NOT, using Parentheses. Expressions can be used and also the DAY, Month and Year functions.
Strict String equality executes and returns results quickly if = or IN is used, but will run less quickly if other
comparison predicates are used. String comparisons are not case sensitive. You can also use a subquery with one parameter with IN.
Null values may be checked in the following manner: expression IS NULL or expression = NULL. You can also use a NULL where a string would be expected in order to specify a null parameter.
You cannot use NULL with numeric or date expressions.