Komapperにおける複数クエリ共通の検索条件の定義方法

Application.kt

package org.komapper.quickstart

import org.komapper.annotation.*
import org.komapper.core.dsl.Meta
import org.komapper.core.dsl.QueryDsl
import org.komapper.core.dsl.expression.PropertyExpression
import org.komapper.core.dsl.expression.WhereDeclaration
import org.komapper.jdbc.JdbcDatabase
import java.time.LocalDateTime

@KomapperEntity
data class Employee(
    @KomapperId @KomapperAutoIncrement
    val id: Int = 0,
    val name: String,
    @KomapperVersion
    val version: Int = 0,
    @KomapperCreatedAt
    val createdAt: LocalDateTime = LocalDateTime.MIN,
    @KomapperUpdatedAt
    val updatedAt: LocalDateTime = LocalDateTime.MIN,
)

@KomapperEntity
data class Address(
    @KomapperId @KomapperAutoIncrement
    val id: Int = 0,
    val name: String,
    @KomapperVersion
    val version: Int = 0,
    @KomapperCreatedAt
    val createdAt: LocalDateTime = LocalDateTime.MIN,
    @KomapperUpdatedAt
    val updatedAt: LocalDateTime = LocalDateTime.MIN,
)


fun main() {
    val database = JdbcDatabase("jdbc:h2:mem:quickstart;DB_CLOSE_DELAY=-1")

    database.withTransaction {
        val e = Meta.employee
        val a = Meta.address

        // EmployeeとAddressのスキーマ作成
        database.runQuery {
            QueryDsl.create(e, a)
        }

        // Employeeの登録        
        database.runQuery { 
            QueryDsl.insert(e).single(Employee(name = "Alice"))
        }

        // Addressの登録
        database.runQuery {
            QueryDsl.insert(a).single(Address(name = "Tokyo"))
        }

        val dateTime = LocalDateTime.of(2024, 1, 1, 0, 0, 0)

        // Employeeの検索
        val employees = database.runQuery {
            // select t0_.id, t0_.name, t0_.version, t0_.created_at, t0_.updated_at from employee as t0_ where t0_.created_at > ?
            QueryDsl.from(e).where {
                // "e.createdAt greater dateTime" と記述するのと同じ意味
                commonWhere(e.createdAt, dateTime)()
            }
        }
        println(employees)

        // Addressの検索
        val addresses = database.runQuery {
            // select t0_.id, t0_.name, t0_.version, t0_.created_at, t0_.updated_at from address as t0_ where t0_.created_at > ?
            QueryDsl.from(a).where {
                // "a.createdAt greater dateTime" と記述するのと同じ意味
                commonWhere(a.createdAt, dateTime)()
            }
        }
        println(addresses)
    }
}

// 複数のクエリで利用できる検索条件
fun commonWhere(createdAt: PropertyExpression<LocalDateTime, LocalDateTime>, dateTime: LocalDateTime) : WhereDeclaration {
    return {
        createdAt greater dateTime
    }
}