With PostgreSql, there is a difference between an empty string value (represented as '') and a NULL value.

With Oracle and SQL-Server, an empty string is always inserted as NULL.

So, if there is a unique constraint on a column and the application insert a empty string, the constraint will be violated for the second insertion.

It would be nice to have an option to insert empty string values as NULL for dotConnect for PostgreSQL, to have the same behavior than Oracle or SQL-Server, and not specifically avoid empty strings in the application to work with PostgreSQL...