In today’s article, we will explain what Is Null and how to use it in PostgreSQL.
Null is not a value, so NULL should not be confused with other values.
Addition, subtraction and comparison of Null with any value always gives a NULL value.
For example NULL=NULL is not equal to value and therefore NULL value is returned.
Let’s make an example
First, let’s select from our student table.
As you can see, the vize value of our last record appears to be NULL.
When we try to set the vize column seen above equal to NULL, the result is not returned.
To obtain NULL (column with no data entered), it will be sufficient to write ‘is null’ after the column in the where condition.