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// Copyright 2019-present Facebook Inc. All rights reserved.
// This source code is licensed under the Apache 2.0 license found
// in the LICENSE file in the root directory of this source tree.
package main
import (
"context"
"fmt"
"log"
"github.com/facebook/ent/examples/o2m2types/ent"
_ "github.com/mattn/go-sqlite3"
)
func Example_O2M2Types() {
client, err := ent.Open("sqlite3", "file:ent?mode=memory&cache=shared&_fk=1")
if err != nil {
log.Fatalf("failed opening connection to sqlite: %v", err)
}
defer client.Close()
ctx := context.Background()
// Run the auto migration tool.
if err := client.Schema.Create(ctx); err != nil {
log.Fatalf("failed creating schema resources: %v", err)
}
if err := Do(ctx, client); err != nil {
log.Fatal(err)
}
// Output:
// User created: User(id=1, age=30, name=a8m)
// a8m
// 2
}
func Do(ctx context.Context, client *ent.Client) error {
// Create the 2 pets.
pedro, err := client.Pet.
Create().
SetName("pedro").
Save(ctx)
if err != nil {
return fmt.Errorf("creating pet: %v", err)
}
lola, err := client.Pet.
Create().
SetName("lola").
Save(ctx)
if err != nil {
return fmt.Errorf("creating pet: %v", err)
}
// Create the user, and add its pets on the creation.
a8m, err := client.User.
Create().
SetAge(30).
SetName("a8m").
AddPets(pedro, lola).
Save(ctx)
if err != nil {
return fmt.Errorf("creating user: %v", err)
}
fmt.Println("User created:", a8m)
// Output: User(id=1, age=30, name=a8m)
// Query the owner. Unlike `Only`, `OnlyX` panics if an error occurs.
owner := pedro.QueryOwner().OnlyX(ctx)
fmt.Println(owner.Name)
// Output: a8m
// Traverse the sub-graph. Unlike `Count`, `CountX` panics if an error occurs.
count := pedro.
QueryOwner(). // a8m
QueryPets(). // pedro, lola
CountX(ctx) // count
fmt.Println(count)
// Output: 2
return nil
}
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