Golang连接mysql执行事务

蔚落 2023-09-29 18:35 14阅读 0赞

#### 文章目录 ####

*  Golang连接mysql执行事务

## Golang连接mysql执行事务 ##

**`接上一节`**：[Golang连接&操作mysql数据库][Golang_mysql]

**下面是一个使用事务的例子：**

*  创建一个订单，如果库存够，则更新album表里面库存数量，然后往album\_order里插入新行，提交事务。最后返回一个订单ID。
 *  如果过程中有失败，则回滚。

// createOrder creates an order for an album and return the new order ID.
    func createOrder(ctx context.Context, albumID, quantity, customID int) (int64, error) {
        
    	// Create a helper function for preparing failure result.
    	fail := func(err error) (int64, error) {
        
    		return 0, fmt.Errorf("createOrder: %v", err)
    	}
    
    	// Get a Tx for making transaction request.
    	tx, err := db.BeginTx(ctx, nil)
    	if err != nil {
        
    		fail(err)
    	}
    	// Defer a rollback in case anything fails
    	defer tx.Rollback()
    
    	// Confirm the album inventory is enough for the order.
    	var enough bool
    	if err = tx.QueryRowContext(ctx, "SELECT (quantity >= ?) FROM album WHERE id = ?", quantity, albumID).Scan(&enough); err != nil {
        
    		if err == sql.ErrNoRows {
        
    			fail(fmt.Errorf("no such album"))
    		}
    		return fail(err)
    	}
    	if !enough {
        
    		fail(fmt.Errorf("no enough inventory"))
    	}
    
    	// Update the album inventory to remove the quantity in the order.
    	_, err = tx.ExecContext(ctx, "UPDATE album SET quantity = quantity - ? WHERE id = ?", quantity, albumID)
    	if err != nil {
        
    		fail(err)
    	}
    
    	// Create a new row in the album_order table.
    	result, err := tx.ExecContext(ctx, "INSERT INTO album_order (album_id, custom_id, quantity, date) values (?, ?, ?, ?)", albumID, customID, quantity, time.Now())
    	if err != nil {
        
    		fail(err)
    	}
    	// Get the ID of the order item just created.
    	orderID, err := result.LastInsertId()
    	if err != nil {
        
    		fail(err)
    	}
    
    	// Commit the transaction.
    	if err = tx.Commit(); err != nil {
        
    		fail(err)
    	}
    
    	// Return the order ID.
    	return orderID, nil
    }

[Golang_mysql]: https://blog.csdn.net/qq_46480020/article/details/128638431?spm=1001.2014.3001.5501