Quarkus JDBC — programmatic SQL

Apply programmatic JDBC patterns in Quarkus with safe SQL and clear transactions.

What is covered in this Skill?

• Injected javax.sql.DataSource (Agroal-backed) and try-with-resources for Connection / PreparedStatement
• PreparedStatement with bind parameters — never string concatenation
• Mapping ResultSet rows to Java records (dedicated mapRow method)
• Safe single-row queries with Optional; never assume rs.next() succeeds
• SQLException translation to domain exceptions (catch-translate-rethrow)
• Streaming large result sets with setFetchSize to avoid OOM
• Batch updates with addBatch / executeBatch for bulk inserts
• @Transactional service boundaries and propagation types (TxType.REQUIRES_NEW for independent commits)
• CDI self-invocation pitfall: always call transactional methods through the injected proxy
• Dev Services for databases in dev/test
• When to prefer Panache (@412) vs raw JDBC

Scope: Apply recommendations based on the reference rules and good/bad code examples.