sqlserver触发器引起的死锁问题

使用一个触发器，只是添加时才触发，目的为了限制ip三分钟发送一条短信，这个表某一段时间内访问频率非常之高，今天高峰时出现了死锁的情况

可能是因为没有判断用户的原因，现在加上用户判断再观察一下，代码大概如下：

 
  ALTER  
  trigger  
  [ 
  dbo 
  ]. 
  [ 
  trg_drv_yzm_insert 
  ]  
  on  
  [ 
  dbo 
  ]. 
  [ 
  drv_yzm 
  ]  
  for  
  insert 
  
 
  as 
  
 
  begin 
  
      
  if ( 
  CURRENT_USER 
  = 
  ' 
  testuser 
  ') 
  
      
  begin 
  
          
  declare  
  @lastcreatet  
  varchar( 
  50) 
  
          
  declare  
  @lastdate  
  datetime 
  
          
  declare  
  @id  
  int, 
  @clientip  
  varchar( 
  15), 
  @type  
  varchar( 
  20) 
  
          
  
          
  select  
  @id 
  =id, 
  @clientip 
  =clientip, 
  @type 
  =type  
  from inserted; 
  
          
  select  
  top  
  1  
  @lastcreatet 
  =createt  
  from drv_yzm  
  where clientip 
  = 
  @clientip  
  and type 
  = 
  ' 
  pre 
  '  
  and id 
  <> 
  @id  
  order  
  by createt  
  desc 
  
 
  
          
  set  
  @lastdate  
  =  
  convert( 
  datetime, 
  substring( 
  left( 
  @lastcreatet, 
  8) 
  + 
  ' 
    
  '  
  +  
  substring( 
  @lastcreatet, 
  9, 
  2) 
  + 
  ' 
  : 
  '  
  +  
  substring( 
  @lastcreatet, 
  11, 
  2) 
  + 
  ' 
  : 
  '  
  +  
  substring( 
  @lastcreatet, 
  13, 
  2), 
  1, 
  17)) 
  
          
  set  
  @lastdate  
  =  
  dateadd(mi, 
  3, 
  @lastdate) 
  
          
  
          
  if( 
  @lastdate 
  > 
  GETDATE()  
  and  
  @type 
  = 
  ' 
  pre 
  ') 
  
              
  update drv_yzm  
  set status 
  = 
  ' 
  0 
  '  
  where id 
  = 
  @id 
  
      
  end 
  
 
  end