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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/m2m2types/ent"
"github.com/facebook/ent/examples/m2m2types/ent/group"
"github.com/facebook/ent/examples/m2m2types/ent/user"
_ "github.com/mattn/go-sqlite3"
)
func Example_M2M2Types() {
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:
// [Group(id=1, name=GitHub) Group(id=2, name=GitLab)]
// [Group(id=1, name=GitHub)]
// [User(id=1, age=30, name=a8m) User(id=2, age=28, name=nati)]
}
func Do(ctx context.Context, client *ent.Client) error {
// Unlike `Save`, `SaveX` panics if an error occurs.
hub := client.Group.
Create().
SetName("GitHub").
SaveX(ctx)
lab := client.Group.
Create().
SetName("GitLab").
SaveX(ctx)
a8m := client.User.
Create().
SetAge(30).
SetName("a8m").
AddGroups(hub, lab).
SaveX(ctx)
nati := client.User.
Create().
SetAge(28).
SetName("nati").
AddGroups(hub).
SaveX(ctx)
// Query the edges.
groups, err := a8m.
QueryGroups().
All(ctx)
if err != nil {
return fmt.Errorf("querying a8m groups: %v", err)
}
fmt.Println(groups)
// Output: [Group(id=1, name=GitHub) Group(id=2, name=GitLab)]
groups, err = nati.
QueryGroups().
All(ctx)
if err != nil {
return fmt.Errorf("querying nati groups: %v", err)
}
fmt.Println(groups)
// Output: [Group(id=1, name=GitHub)]
// Traverse the graph.
users, err := a8m.
QueryGroups(). // [hub, lab]
Where(group.Not(group.HasUsersWith(user.Name("nati")))). // [lab]
QueryUsers(). // [a8m]
QueryGroups(). // [hub, lab]
QueryUsers(). // [a8m, nati]
All(ctx)
if err != nil {
return fmt.Errorf("traversing the graph: %v", err)
}
fmt.Println(users)
// Output: [User(id=1, age=30, name=a8m) User(id=2, age=28, name=nati)]
return nil
}
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