at/rollback/server2/update.go

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

package main

import (
	"context"
	"fmt"
	"time"
)

func updateDataFail(ctx context.Context) error {
	// generate an err : data row not exists where id=10000 , affected rows is 0.
	sql := "update order_tbl set descs=? where id=?"
	ret, err := db.ExecContext(ctx, sql, fmt.Sprintf("NewDescs1-%d", time.Now().UnixMilli()), 10000)
	if err != nil {
		fmt.Printf("update failed, err:%v\n", err)
		return err
	}

	rows, err := ret.RowsAffected()
	if err != nil {
		fmt.Printf("update failed, err:%v\n", err)
		return err
	}
	fmt.Printf("update success： %d.\n", rows)
	if rows == 0 {
		return fmt.Errorf("rows affected 0")
	}
	return nil
}