这段代码生成的 `dict` 只包含创建 `item` 模型时显式设置的数据，而不包括默认值。

然后再用它生成一个只含已设置（在请求中所发送）数据，且省略了默认值的 `dict`：

{* ../../docs_src/body_updates/tutorial002.py hl[34] *}

### 使用 Pydantic 的 `update` 参数

接下来，用 `.copy()` 为已有模型创建调用 `update` 参数的副本，该参数为包含更新数据的 `dict`。

例如，`stored_item_model.copy(update=update_data)`：

{* ../../docs_src/body_updates/tutorial002.py hl[35] *}

### 更新部分数据小结

简而言之，更新部分数据应：

* 使用 `PATCH` 而不是 `PUT` （可选，也可以用 `PUT`）；

    public synchronized void insert(final SynonymItem item) {
        try (SynonymUpdater updater = new SynonymUpdater(item)) {
            reload(updater);
        }
    }

    @Override
    public synchronized void update(final SynonymItem item) {
        try (SynonymUpdater updater = new SynonymUpdater(item)) {
            reload(updater);
        }
    }

    @Override

		t.Errorf("failed to return updated age column")
	}
}

func TestUpdateWithDiffSchema(t *testing.T) {
	user := GetUser("update-diff-schema-1", Config{})
	DB.Create(&user)

	type UserTemp struct {
		Name string
	}

	err := DB.Model(&user).Updates(&UserTemp{Name: "update-diff-schema-2"}).Error
	AssertEqual(t, err, nil)
	AssertEqual(t, "update-diff-schema-2", user.Name)
}

		return fmt.Sprintf("You are running an older version of MinIO released %s, update: %s", newerThan, downloadURL)
	}

	// Return the nicely colored and formatted update message.
	return colorizeUpdateMessage(downloadURL, newerThan)
}

// colorizeUpdateMessage - inspired from Yeoman project npm package https://github.com/yeoman/update-notifier
func colorizeUpdateMessage(updateString string, newerThan string) string {

		line1 := fmt.Sprintf("%s %s", plainMsg, color.YellowBold(testCase.expectedSubStr))
		line2 := fmt.Sprintf("Update: %s", color.CyanBold(testCase.dlURL))
		// Uncomment below to see message appearance:
		// fmt.Println(output)
		switch {
		case testCase.dlURL == "" && output != "":
			t.Errorf("Testcase %d: no newer release available but got an update message: %s", i+1, output)
		case output == "" && testCase.dlURL != "" && testCase.older > 0:

		cusUser := CustomizeUser{
			Name: "update-has-one-associations",
			Account: CustomizeAccount{
				Number:  number,
				Number2: number,
			},
		}

		if err := DB.Create(&cusUser).Error; err != nil {
			t.Fatalf("errors happened when create: %v", err)
		}
		cusUser.Account.Number += "-update"
		cusUser.Account.Number2 += "-update"

        project.findProperty("currentReleasedVersionBuildTimestamp").toString()
    )
}

val updateAgpVersions = tasks.register<UpdateAgpVersions>("updateAgpVersions") {
    comment = " Generated - Update by running `./gradlew updateAgpVersions`"
    currentGradleVersion = gradleModule.identity.version
    propertiesFile = layout.projectDirectory.file("gradle/dependency-management/agp-versions.properties")

     * This includes namespace updates and module conversion using domtrip.
     * Returns the upgraded document.
     */
    private Document performModelUpgrade(
            Document pomDocument, UpgradeContext context, String currentVersion, String targetModelVersion) {
        // Create Editor from domtrip Document
        Editor editor = new Editor(pomDocument);

        // Update model version element

            }
        }
        return target;
    }

    /**
     * Updates a document with additional metadata and enhancements.
     * Adds click counts, favorite counts, document boosting, and generates document ID.
     * Also applies language-specific updates through the language helper.
     *
     * @param map the document data map to update with additional metadata
     */

				}
			}
		}

		return tx.Model(dest).Updates(assigns)
	}

	return tx
}

// Update updates column with value using callbacks. Reference: https://gorm.io/docs/update.html#Update-Changed-Fields
func (db *DB) Update(column string, value interface{}) (tx *DB) {
	tx = db.getInstance()
	tx.Statement.Dest = map[string]interface{}{column: value}
	return tx.callbacks.Update().Execute(tx)
}