It'd be more accurate to say the illusion of type safety.
Under the hood many[0] ORMs simply construct a query similar to my example above and then convert result set of tabulated strings to the appropriate types (usually using reflection).
This means two things:
First, that the "type-safety" portions of an ORM are really located in the "mapping" code, so not really related to querying.
And second: you don't really have type safety. A database schema could change at any time and break the code even if static analysis seems to think it should work.
[0] Notable exceptions are languages that offer type providers (e.g. F#) but I digress
Under the hood many[0] ORMs simply construct a query similar to my example above and then convert result set of tabulated strings to the appropriate types (usually using reflection).
This means two things:
First, that the "type-safety" portions of an ORM are really located in the "mapping" code, so not really related to querying.
And second: you don't really have type safety. A database schema could change at any time and break the code even if static analysis seems to think it should work.
[0] Notable exceptions are languages that offer type providers (e.g. F#) but I digress