What if a database NULL assigned to a not-null Delphi field?

BIZ TMS Aurelius
1

Question 1: For example, the following mapping: FDateis mapped as NULLABLE (i.e., optional/not-required) database field, but its underlying Delphi type is not nullable?

    [Column('Date', [], 255)]
    FDate: TDate;

Question 2:
In the context of Aurelius, is string a nullable type? Do I need to use Nullable < string > ? Is it even meaningful?

2

  1. When reading from the database, it will get the default value of TDate, which is 0 (zero), meaning date 31/12/1899.

  2. string is not a nullable type in Aurelius context. It can hold only empty string, which is different from null values. However, you have to take into account that some databases consider NULL and empty string as the same thing. Also, the underlying database access component library you are using might have also options that treat empty string as nulls.