检查已提交的事务，如果是 return 一个值

Question

我想在 table 个用户中插入一个新用户（电子邮件地址）。如果成功（无重复），将新用户的基本配置插入其他tables，并return一些数据到客户端。如果不成功，在C#项目的dataset中收到相关通知。

这是示例代码，您可以轻松地对其发表评论

ALTER PROCEDURE [dbo].[CreateUser] 
  @Email nvarchar(256),   
  @Password nvarchar(256)   
AS
BEGIN
  declare @UserID uniqueidentifier;
  declare @ConfigID uniqueidentifier;
  declare @TopMostNode uniqueidentifier;

  BEGIN TRANSACTION;
    select @UserID = NEWID();
    select @ConfigID = newid();

    insert into Users (UserID,Email,Password,CurrentConfig) 
      values(@UserID, @Email, @Password, @ConfigID);

    INSERT INTO Configs (ConfigID, OwnerID, DisplayName, LastPrintID)
      VALUES (@ConfigID,@UserID, 'Default Config', 1);

  COMMIT TRANSACTION 
END

Answer 1

这是一种可能，您 return 一个包含您需要的数据的记录集和一个指示用户是否已经存在的标志。

alter procedure [dbo].[CreateUser]
(
  @Email nvarchar(256)  
  , @Password nvarchar(256)
)
as
begin
  declare @UserID uniqueidentifier, @ConfigID uniqueidentifier, @TopMostNode uniqueidentifier, @UserExists bit = 0;

  select @UserID = UserID, @UserExists = 1 from Users where Email = @Email;

  if @UserExists = 0 begin
    begin transaction;
      set @UserID = newid();
      set @ConfigID = newid();

      insert into Users (UserID, Email, [Password], CurrentConfig) 
        values (@UserID, @Email, @Password, @ConfigID);

      insert into Configs (ConfigID, OwnerID, DisplayName, LastPrintID)
        values (@ConfigID, @UserID, 'Default Config', 1);

    commit transaction 
  end

  -- Return whether the user already exists or not and the user id
  select @UserExists, @UserId

  return 0;
end

向应用程序 return 发送数据的另一种方法是使用 output 参数，例如

alter procedure [dbo].[CreateUser]
(
  @Email nvarchar(256)  
  , @Password nvarchar(256)
  , @UserId uniqueidentifier out
  , @UserExists bit out
)
as
begin
  declare @ConfigID uniqueidentifier, @TopMostNode uniqueidentifier;

  set @UserExists = 0;

  select @UserID = UserID, @UserExists = 1 from Users where Email = @Email;

  if @UserExists = 0 begin
    begin transaction;
      set @UserID = newid();
      set @ConfigID = newid();

      insert into Users (UserID, Email, [Password], CurrentConfig) 
        values (@UserID, @Email, @Password, @ConfigID);

      insert into Configs (ConfigID, OwnerID, DisplayName, LastPrintID)
        values (@ConfigID, @UserID, 'Default Config', 1);

    commit transaction 
  end

  return 0;
end

Answer 2

该代码即将完成。只需要添加一个 SELECT 到 return 的新键。如果出现错误，您将获得异常。例如：

ALTER PROCEDURE [dbo].[CreateUser] 
  @Email nvarchar(256),   
  @Password nvarchar(256)   
AS
BEGIN
  declare @UserID uniqueidentifier;
  declare @ConfigID uniqueidentifier;
  declare @TopMostNode uniqueidentifier;

  BEGIN TRANSACTION;
    select @UserID = NEWID();
    select @ConfigID = newid();

    insert into Users (UserID,Email,Password,CurrentConfig) 
      values(@UserID, @Email, @Password, @ConfigID);

    INSERT INTO Configs (ConfigID, OwnerID, DisplayName, LastPrintID)
      VALUES (@ConfigID,@UserID, 'Default Config', 1);

  COMMIT TRANSACTION 
  select @UserID UserID, @ConfigID ConfigID;
END

检查已提交的事务，如果是 return 一个值

Check transaction committed and if so return a value

sql-server

stored-procedures

commit

return-value