Komapperでエンティティの関連づけを行うAPIの例

AssociationExample.kt

val d = Dept.meta
val e = Emp.meta

val query = SqlDsl.from(d).innerJoin(e){ d.id eq e.deptId }.associate(d, e)
val aggregate = db.runQuery { query }
val map: Map<Dept, Set<Emp>> = aggregate.oneToMany(d, e)

AssociationExample2.kt

// associateを呼んだ分だけ実行結果から関連づけされたMapを取得できる

val d = Dept.meta
val e = Emp.meta
val a = Address.meta

val query = SqlDsl.from(d)
  .innerJoin(e){ d.id eq e.deptId }
  .innerJoin(a){ a.id eq e.addressId }
  .associate(d, e)
  .associate(e, a)
val aggregate = db.runQuery { query }
val map1: Map<Dept, Set<Emp>> = aggregate.oneToMany(d, e)
val map2: Map<Emp, Address?> = aggregate.oneToOne(e, a)