PQL Not Null

PQL NOT NULL Constraint
By default, a stable column can hold NULL values. The NOT NULL constraint enforces a column to NOT accept NULL values. The NOT NULL constraint enforces a field to always contain a value. This means that you cannot insert a new record, or update a record without adding a value to this field.

The following PQL enforces the "P_Id" column and the "LastName" column to not accept NULL values: This is normally done to make sure that columns that are used as unique identifiers for each row in a stable, and often automatically incremented, contains a value. Like in our example where we use the P_Id as an identifier.