Caution. You cannot use simple case to test for null because it always uses the equals operator ( = ). That is because the condition null = null is not true5—consequently, a when null clause never applies. If the <common operand> is null , the else clause applies .
Read moreHow do you indicate NULL?
The Greek lowercase omega (ω) character is used to represent Null in database theory.
Read moreHow do you put a NULL in a query?
You also can specify the NULL keyword in the VALUES clause to indicate that a column should be assigned a NULL value . The following example inserts values into three columns of the orders table: INSERT INTO orders (orders_num, order_date, customer_num) VALUES (0, NULL, 123);
Read moreAre null checks bad?
Generally speaking, returning null from a method should be considered really bad . This forces the user of the method to do null checks and create conditional code paths.
Read moreWhere do you put null checks?
If you have implemented layering in your project, good place to do null checks are the layers that receives data externally .
Read moreAre null checks good?
It is a good idea to check for null explicitly because: You can catch the error earlier. You can provide a more descriptive error message.
Read moreHow do you check for null and null?
How to Test for NULL Values? It is not possible to test for NULL values with comparison operators, such as =, <, or <>. We will have to use the IS NULL and IS NOT NULL operators instead.
Read more