Java ORM tools are mature for RDBMS, but MongoDB's document model needs ODM (Object-Document Mapping) for clean Java integration. This post surveys the landscape and introduces dbVisitor as a JDBC-based solution.

Simple rules like @{and, name = :name} handle single conditions well, but real-world queries often need nested logic like (A AND B) OR (C AND D). This article shows how dbVisitor rules handle complex compound conditions in one line.

A normal SELECT * loads all results into memory, easily causing OOM on huge tables. This article shows how to use dbVisitor's streaming query to read MySQL tables of any size safely.