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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/edgeindex/ent"
_ "github.com/mattn/go-sqlite3"
)
func Example_EdgeIndex() {
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:
}
func Do(ctx context.Context, client *ent.Client) error {
// Unlike `Save`, `SaveX` panics if an error occurs.
tlv := client.City.
Create().
SetName("TLV").
SaveX(ctx)
nyc := client.City.
Create().
SetName("NYC").
SaveX(ctx)
// Add a street "ST" to "TLV".
client.Street.
Create().
SetName("ST").
SetCity(tlv).
SaveX(ctx)
// This operation will fail because "ST"
// is already created under "TLV".
_, err := client.Street.
Create().
SetName("ST").
SetCity(tlv).
Save(ctx)
if err == nil {
return fmt.Errorf("expecting creation to fail")
}
// Add a street "ST" to "NYC".
client.Street.
Create().
SetName("ST").
SetCity(nyc).
SaveX(ctx)
return nil
}
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