[#1977] Remove the confusing concept of having a "main key" as opposed
to a "primary key"
[#1977] Remove the confusing concept of having a "main key" as opposed
to a "primary key" - Fixed generated code
[#1977] Remove the confusing concept of having a "main key" as opposed
to a "primary key" - Fixed the sample databases. T_BOOK_STORE shall
have a primary key, instead of a UNIQUE key
[#1977] Remove the confusing concept of having a "main key" as opposed
to a "primary key" - Regenerated H2, Oracle, Postgres