NotesRoute.kt

fun Application.notesRoutes() {
    val db = DatabaseConnection.database

    routing {
        get("/notes") {
            val notes = db.from(NotesEntity).select().map {
                val id = it[NotesEntity.id]
                val note = it[NotesEntity.note]
                Note(id ?: -1, note ?: "")
            }
            call.respond(notes)
        }

        post("/notes") {
            val request = call.receive<NoteRequest>()
            val result = db.insert(NotesEntity) {
                set(it.note, request.note)
            }

            // Verify only 1 row has been inserted
            if (result == 1) {
                // To Successful response to the client
                call.respond(
                    HttpStatusCode.OK,
                    NoteResponse(
                        success = true,
                        data = "Value has been successfully inserted"
                    )
                )
            } else {
                // Send Failure response to the client
                call.respond(
                    HttpStatusCode.BadRequest,
                    NoteResponse(
                        success = false,
                        data = "Failed to Insert Value"
                    )
                )
            }
        }

        get("/notes/{id}") {
            val id: Int = call.parameters["id"]?.toInt() ?: -1
            val note = db.from(NotesEntity)
                .select()
                .where { NotesEntity.id eq id }
                .map {
                    val note = it[NotesEntity.note]!!
                    Note(id = id, note = note)
                }.firstOrNull()
            if (note == null) {
                call.respond(
                    HttpStatusCode.NotFound,
                    NoteResponse(success = false, data = "Could not find note with that id = $id")
                )
            } else {
                call.respond(
                    HttpStatusCode.OK,
                    NoteResponse(success = true, data = note)
                )
            }
        }

        put("/notes/{id}") {
            val id = call.parameters["id"]?.toInt() ?: -1
            val updatedNote = call.receive<NoteRequest>()
            val rowsEffected = db.update(NotesEntity) {
                set(it.note, updatedNote.note)
                where {
                    it.id eq id
                }
            }
            if (rowsEffected != 1) {
                call.respond(
                    HttpStatusCode.NotFound,
                    NoteResponse(success = false, data = "Could not find note with that id = $id")
                )
            } else {
                call.respond(
                    HttpStatusCode.OK,
                    NoteResponse(success = true, data = "Success")
                )
            }
        }

        delete("/notes/{id}") {
            val id: Int = call.parameters["id"]?.toInt() ?: -1
            val rowsEffected = db.delete(NotesEntity) {
                it.id eq id
            }
            if (rowsEffected != 1) {
                call.respond(
                    HttpStatusCode.NotFound,
                    NoteResponse(success = false, data = "Could not find note with that id = $id")
                )
            } else {
                call.respond(
                    HttpStatusCode.OK,
                    NoteResponse(success = true, data = "Success")
                )
            }
        }
    }

}