public void RemoveAuthorWithBooksUsingTransaction()
{
var transactionTask = new TransactionTask(dbContext =>
{
var firstAuthor = dbContext.Set <Author>().FirstOrDefault(a => a.Books.Any());
dbContext.Remove(firstAuthor);
dbContext.SaveChanges();
});
var transanctionTaskResult = transactionTaskManager.UseTransaction(transactionTask);
transanctionTaskResult.Failure.Should().BeTrue();
transanctionTaskResult.Exception.Should().BeAssignableTo <DbUpdateException>();
}
private TransactionTaskResult TryUseTransaction(TransactionTask transactionTask)
{
using (var dbContext = _newDbContext())
using (var transaction = dbContext.Database.BeginTransaction())
try
{
transactionTask.Action(dbContext);
dbContext.SaveChanges();
transaction.Commit();
var transactionTaskSuccess = new TransactionTaskResult(transaction.TransactionId, transactionTask);
return(transactionTaskSuccess);
}
catch (Exception e)
{
transaction.Rollback();
var transactionTaskFailure = new TransactionTaskResult(transaction.TransactionId, transactionTask, e);
return(transactionTaskFailure);
}
}
public void InsertAndUpdateBooksUsingTransaction()
{
var newAuthor = fakerAuthor.Generate();
var transactionTask = new TransactionTask(dbContext =>
{
var authorDbSet = dbContext.Set <Author>();
var bookDbSet = dbContext.Set <Book>();
authorDbSet.Add(newAuthor);
var authorsInserted = dbContext.SaveChanges();
var firstAuthor = authorDbSet.FirstOrDefault();
var booksFirstAuthor = bookDbSet.AsTracking().Where(b => b.AuthorId == firstAuthor.AuthorId).ToList();
booksFirstAuthor.ForEach(b => b.AuthorId = newAuthor.AuthorId);
var booksUpdated = dbContext.SaveChanges();
});
var transanctionTaskResult = transactionTaskManager.UseTransaction(transactionTask);
transanctionTaskResult.Success.Should().BeTrue();
}
/// <summary>
/// 取分布式锁（基于DB方式）
/// </summary>
/// <param name="moduleFlag">模块标识，模块表名/类名</param>
/// <param name="method_Flag">方法名标识</param>
/// <param name="expirtime">自定义过期时间（秒）</param>
/// <param name="des">锁描述</param>
/// <returns></returns>
public static string DistributeDbLock(string moduleFlag, string method_Flag, double?expirtime = null, string des = null)
{
try
{
if (WebConfigHelper.GetAppSettingValue("EnabledDistributeLock") != "true") //未启用分布式锁
{
return(string.Empty);
}
string hostname = System.Net.Dns.GetHostName(); //当前服务器
string processId = ApplicationObject.GetCurrentProcessId(); //当前进程
string threadId = ApplicationObject.GetCurrentThreadId(); //当前线程
lock (tempObjDistriLock)
{
string errMsg = string.Empty;
int timeout = 30; //30秒超时
DateTime initTime = DateTime.Now;
DatabaseType dbType = DatabaseType.MsSqlServer;
string connStr = ModelConfigHelper.GetModelConnStr(typeof(Other_DistributedLock), out dbType, false);
while ((DateTime.Now - initTime).TotalSeconds <= timeout)
{
double updateTimesamp = Globals.GetTimestamp(DateTime.Now); //当前时间戳
double invalidTimesamp = expirtime.HasValue && expirtime.Value > 0 ? updateTimesamp + expirtime.Value : updateTimesamp + 20; //过期时间戳
Other_DistributedLock methodLock = CommonOperate.GetEntity <Other_DistributedLock>(x => x.ModuleFlag == moduleFlag && x.Method_Flag == method_Flag && x.Invalid_Timesamp > updateTimesamp, null, out errMsg);
//锁存在，继续循环再取
if (methodLock != null)
{
Thread.Sleep(10);
continue;
}
//锁不存在，取得锁成功，插入锁标识
methodLock = new Other_DistributedLock()
{
ModuleFlag = moduleFlag,
Method_Flag = method_Flag,
Update_Timesamp = updateTimesamp,
Invalid_Timesamp = invalidTimesamp,
Maching = hostname,
ProcessId = processId,
ThreadId = threadId,
Des = des
};
TransactionTask tranAction = (conn) =>
{
CommonOperate.DeleteRecordsByExpression <Other_DistributedLock>(x => x.ModuleFlag == moduleFlag && x.Method_Flag == method_Flag, out errMsg, false, connStr, dbType, conn);
if (!string.IsNullOrEmpty(errMsg))
{
throw new Exception(errMsg);
}
CommonOperate.OperateRecord <Other_DistributedLock>(methodLock, ModelRecordOperateType.Add, out errMsg, null, false, false, connStr, dbType, conn);
if (!string.IsNullOrEmpty(errMsg))
{
throw new Exception(errMsg);
}
};
CommonOperate.TransactionHandle(tranAction, out errMsg, connStr, dbType);
//取锁成功
if (string.IsNullOrEmpty(errMsg))
{
return(string.Empty);
}
else
{
WritLockLog(moduleFlag, method_Flag, errMsg);
}
//取锁失败，继续循环取
Thread.Sleep(10);
}
return("获取分布式锁超时"); //取锁失败
}
}
catch
{
return(string.Empty);
}
}
/// <summary> /// 执行事务 /// </summary> /// <param name="transTask">事务处理函数</param> /// <param name="errorMsg">异常信息</param> /// <param name="connString">数据库连接字符串</param> public abstract void TransactionHandle(TransactionTask transTask, out string errorMsg, string connString = null);
/// <summary>
/// 执行事务
/// </summary>
/// <param name="transTask">事务处理函数</param>
/// <param name="errorMsg">异常信息</param>
/// <param name="connString">数据库连接字符串</param>
public void TransactionHandle(TransactionTask transTask, out string errorMsg, string connString = null)
{
errorMsg = string.Empty;
_dal.TransactionHandle(transTask, out errorMsg, connString);
}
public TransactionTaskResult UseTransaction(TransactionTask transactionTask)
=> transactionTask is null
? throw new ArgumentNullException(nameof(transactionTask))
