sql server2000存储过程sp_password

create procedure sp_password
    @old sysname = NULL,        -- the old (current) password
    @new sysname,               -- the new password
    @loginame sysname = NULL    -- user to change password on
as
    -- SETUP RUNTIME OPTIONS / DECLARE VARIABLES --
 set nocount on
    declare @self int
    select @self = CASE WHEN @loginame is null THEN 1 ELSE 2 END

    -- RESOLVE LOGIN NAME
    if @loginame is null
        select @loginame = suser_sname()

    -- CHECK PERMISSIONS (SecurityAdmin per Richard Waymire) --
 IF (not is_srvrolemember('securityadmin') = 1)
        AND not @self = 1
 begin
    dbcc auditevent (107, @self, 0, @loginame, NULL, NULL, NULL)
    raiserror(15210,-1,-1)
    return (1)
 end
 ELSE
 begin
    dbcc auditevent (107, @self, 1, @loginame, NULL, NULL, NULL)
 end

    -- DISALLOW USER TRANSACTION --
 set implicit_transactions off
 IF (@@trancount > 0)
 begin
  raiserror(15002,-1,-1,'sp_password')
  return (1)
 end

    -- RESOLVE LOGIN NAME (disallows nt names)
    if not exists (select * from master.dbo.syslogins where
                    loginname = @loginame and isntname = 0)
 begin
  raiserror(15007,-1,-1,@loginame)
  return (1)
 end

 -- IF non-SYSADMIN ATTEMPTING CHANGE TO SYSADMIN, REQUIRE PASSWORD (218078) --
 if (@self <> 1 AND is_srvrolemember('sysadmin') = 0 AND exists
   (SELECT * FROM master.dbo.syslogins WHERE loginname = @loginame and isntname = 0
    AND sysadmin = 1) )
  SELECT @self = 1

    -- CHECK OLD PASSWORD IF NEEDED --
    if (@self = 1 or @old is not null)
        if not exists (select * from master.dbo.sysxlogins
                        where srvid IS NULL and
            name = @loginame and
                     ( (@old is null and password is null) or
                              (pwdcompare(@old, password, (CASE WHEN xstatus&2048 = 2048 THEN 1 ELSE 0 END)) = 1) )   )
        begin
      raiserror(15211,-1,-1)
      return (1)
     end

    -- CHANGE THE PASSWORD --
    update master.dbo.sysxlogins
 set password = convert(varbinary(256), pwdencrypt(@new)), xdate2 = getdate(), xstatus = xstatus & (~2048)
 where name = @loginame and srvid IS NULL

 -- UPDATE PROTECTION TIMESTAMP FOR MASTER DB, TO INDICATE SYSLOGINS CHANGE --
 exec('use master grant all to null')

    -- FINALIZATION: RETURN SUCCESS/FAILURE --
 if @@error <> 0
        return (1)
    raiserror(15478,-1,-1)
 return  (0) -- sp_password