Query Object Pattern
Definition
A Query Object is an interpreter, that is, a structure of objects that can form itself into a SQL query (martin fowler).
Applicability
- When there is a need to avoid to know what the database schema looks like to form queries.
Consequences
- Hides the SQL inside parameterized methods.
- Those who write the queries can do so independently of the database schema and changes to the schema can be localized in a single place.
Downsides
- Makes it difficult to form more ad hoc queries.
Sample Code
Comments