转账存储过程有关问题，求解

转账存储过程问题，求解！
create procedure transpro
 @aid1 float, @aid2 float,@num int
 as
 begindeclare @ye int
 declare @error int
 begin transaction 
select @ye=jine from account where aid=@aid1 if(@num > @ye)
  begin
  print '卡上余额不足'
  rollback transaction
  end  
else
  update account set jine=jine+@num where aid=@aid2
  set @error=@error+@@error
  update account set jine=jine-@num where aid=@aid1
  set @error=@error+@@error
  if @error>0
  begin
  print '转账失败！'
  rollback transaction
  end
  else 
  begin
  print '转账成功！'
  commit transaction
  end
 end 当转账金额为2000 而余额只有800的时候，也能输出 转账成功这是怎么回事，不知道哪里有问题，请各位大侠帮忙啊！

[解决办法]
先帮你格式化一下代码，这样没人看的

SQL code

CREATE PROCEDURE transpro  @aid1 FLOAT,  @aid2 FLOAT,  @num  INTASBEGIN  DECLARE @ye INT  DECLARE @error INT  BEGIN TRANSACTION  SELECT    @ye = jine  FROM   account  WHERE    aid = @aid1  IF(@num > @ye)  BEGIN    PRINT '卡上余额不足'    ROLLBACK TRANSACTION  END  ELSE    UPDATE account    SET    jine = jine + @num    WHERE  aid = @aid2  SET @error=@error + @@error  UPDATE account  SET    jine = jine - @num  WHERE  aid = @aid1  SET @error=@error + @@error  IF @error > 0  BEGIN    PRINT '转账失败！'    ROLLBACK TRANSACTION  END  ELSE  BEGIN    PRINT '转账成功！'    COMMIT TRANSACTION  ENDEND
[解决办法]
余额足够才进行转账，看你的代码觉得Else和最后一个End之间的代码是@num <= @ye时才执行的，因此要在Else和最后一个End之间加上Begin...End。

SQL code
CREATE PROCEDURE transpro  @aid1 FLOAT,  @aid2 FLOAT,  @num  INTASBEGIN  DECLARE @ye INT  DECLARE @error INT  BEGIN TRANSACTION  SELECT    @ye = jine  FROM   account  WHERE    aid = @aid1  IF(@num > @ye)  BEGIN    PRINT '卡上余额不足'    ROLLBACK TRANSACTION  END  ELSE  BEGIN    UPDATE account    SET    jine = jine + @num    WHERE  aid = @aid2    SET @error=@error + @@error    UPDATE account    SET    jine = jine - @num    WHERE  aid = @aid1    SET @error=@error + @@error    IF @error > 0    BEGIN      PRINT '转账失败！'      ROLLBACK TRANSACTION    END    ELSE    BEGIN      PRINT '转账成功！'      COMMIT TRANSACTION    END  ENDEND
[解决办法]
if /else 如果没有加begin /end 的话，默认只执行最接近这个关键字的那句操作，所以建议楼主要规范化编程。不然会有很多后续问题浪费你时间