if f.Size == 0 {
			f.Size = ref.ForeignKey.Size
		}
		ref.ForeignKey = f
	}

	for name, rel := range relation.JoinTable.Relationships.Relations {
		if _, ok := joinSchema.Relationships.Relations[name]; !ok {
			rel.Schema = joinSchema
			joinSchema.Relationships.Relations[name] = rel
		}
	}
	relation.JoinTable = joinSchema

	return nil
}

// Use use plugin
func (db *DB) Use(plugin Plugin) error {

		t.Fatalf("Should find 3 tags")
	}

	var blog1 Blog
	DB.Preload("Tags").Find(&blog1)
	if !compareTags(blog1.Tags, []string{"tag1", "tag2", "tag3"}) {
		t.Fatalf("Preload many2many relations")
	}

	// Replace
	tag5 := &Tag{Locale: "ZH", Value: "tag5"}
	tag6 := &Tag{Locale: "ZH", Value: "tag6"}
	DB.Model(&blog).Association("Tags").Replace(tag5, tag6)
	var tags2 []Tag

							return err
						}
					}
				}

				if !m.DB.DisableForeignKeyConstraintWhenMigrating && !m.DB.IgnoreRelationshipsWhenMigrating {
					for _, rel := range stmt.Schema.Relationships.Relations {
						if rel.Field.IgnoreMigration {
							continue
						}
						if constraint := rel.ParseConstraint(); constraint != nil &&

De plus, la meilleure approche était d'utiliser des normes déjà existantes.

Ainsi, avant même de commencer à coder **FastAPI**, j'ai passé plusieurs mois à étudier les spécifications d'OpenAPI, JSON Schema, OAuth2, etc. Comprendre leurs relations, leurs similarités et leurs différences.

## Conception { #design }

Ensuite, j'ai passé du temps à concevoir l'« API » de développeur que je voulais avoir en tant qu'utilisateur (en tant que développeur utilisant FastAPI).

				}
			}

			relation, ok := db.Statement.Schema.Relationships.Relations[association]
			if !ok {
				if preloadFields := strings.Split(association, "."); len(preloadFields) > 1 {
					relationships := &db.Statement.Schema.Relationships
					for _, field := range preloadFields {
						var ok bool
						relation, ok = relationships.Relations[field]
						if ok {
							relationships = &relation.FieldSchema.Relationships

		Fields:           make([]*Field, 0, 10),
		FieldsByName:     make(map[string]*Field, 10),
		FieldsByBindName: make(map[string]*Field, 10),
		FieldsByDBName:   make(map[string]*Field, 10),
		Relationships:    Relationships{Relations: map[string]*Relationship{}},
		cacheStore:       cacheStore,
		namer:            namer,
		initialized:      make(chan struct{}),
	}
	// When the schema initialization is completed, the channel will be closed

  /**
   * Verify thread safety by using a collection whose size() may be inconsistent with the actual
   * number of elements and whose elements may change over time.
   *
   * <p>This test might fail in GWT because the GWT emulations might count on the input collection
   * not to change during the copy. It is safe to do so in GWT because javascript is
   * single-threaded.
   */
  @GwtIncompatible // GWT is single threaded

         *
         * TODO(cpovirk): Consider checking onlyOnRight.containsKey instead of right.containsKey.
         * That could change behavior if the input maps use different equivalence relations (and so
         * a key that appears once in `right` might appear multiple times in `left`). We don't
         * guarantee behavior in that case, anyway, and the current behavior is likely undesirable.

         *
         * TODO(cpovirk): Consider checking onlyOnRight.containsKey instead of right.containsKey.
         * That could change behavior if the input maps use different equivalence relations (and so
         * a key that appears once in `right` might appear multiple times in `left`). We don't
         * guarantee behavior in that case, anyway, and the current behavior is likely undesirable.

## 0.30.0 (2019-06-20)

* Add support for Pydantic's ORM mode:
    * Updated documentation about SQL with SQLAlchemy, using Pydantic models with ORM mode, SQLAlchemy models with relations, separation of files, simplification of code and other changes. New docs: [SQL (Relational) Databases](https://fastapi.tiangolo.com/tutorial/sql-databases/).