Free your mind with JDBI

using explicit SQL mappers...

...in enterprise applications

Maciej Małecki, Architecture Community, Capgemini 2021.

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↔

Why?

1: SQL-POJO binding

2: SQL dialect-agnostic

3: transparent persistence

Transparent persistence

change detection

associations

n+1

proxies

no boundaries

fetching strategies

entity graphs

stateful session

⇯⇯⇯ hidden complexity ⇯⇯⇯

What are the SQL mappers?

1: SQL-POJO binding

When should I consider a mapper?

🧅, hexagonal, DDD
"read-only" app - dump data on screen
"write-only" app - data importers & updaters
CQRS
event sourcing
"small" apps of any kind

SQL ↭ POJO mapper

fluent API

... or declarative API

wraps around JDBC

native SQL

no limitations

no fake persistence

get what you code

(and nothing more)

JDBI

example config in Spring

... and the same in Spring/Kotlin

Simple SELECT

... and in Kotlin

Simple INSERT

or simply

or bean mapped INSERT

Result beans

if names are excluded from the bytecode

... or use Kotlin

SQL Object

SQL Objects / Transactions

Templating

Find by criteria (Devonfw style)

"advanced" topics

Entity & event sourcing