create trigger opera on Access
instead of insert
as
begin
    if exists (select 1 from inserted where mark='取')
    begin
        if exists (select 1 from inserted a inner join Depositor b on a.dno = b.dno and a.mark='取' and a.accessnum>b.remainder)
        begin
            print '该客户没有足够的金额可取'
            rollback tran
        end
        
        update Depositor set remainder = remainder - accessnum
        from Depositor a inner join inserted b on a.dno = b.dno and b.mark='取'
    
    end
    
    if exists (select 1 from inserted where mark='存' )
    begin
        update Depositor set remainder = remainder + accessnum
        from Depositor a inner join inserted b on a.dno = b.dno and b.mark='存'
        
    end

    insert into Access
    select * from inserted
end

create trigger opera on Access
instead of insert
as
begin
    if exists (select 1 from inserted where mark='取')
    begin
        if exists (select 1 from inserted a inner join Depositor b on a.dno = b.dno and a.mark='取' and a.accessnum>b.remainder)
        begin
            print '该客户没有足够的金额可取'
            rollback tran
        end
      else 
        begin 
           update Depositor set remainder = remainder - accessnum
           from Depositor a inner join inserted b on a.dno = b.dno and b.mark='取'
        end   
    end
    
    if exists (select 1 from inserted where mark='存' )
    begin
        update Depositor set remainder = remainder + accessnum
        from Depositor a inner join inserted b on a.dno = b.dno and b.mark='存'
        
    end

    insert into Access
    select * from inserted
end

------解决方案--------------------
SQL code

create trigger opera on Access
instead of insert
as
begin
    if exists (select 1 from inserted where mark='取')
    begin
        if exists (select 1 from inserted a inner join Depositor b on a.dno = b.dno and a.mark='取' and a.accessnum>b.remainder)
        begin
            print '该客户没有足够的金额可取'
            rollback tran
        end
        else
        begin
        
        update Depositor set remainder = remainder - accessnum
        from Depositor a inner join inserted b on a.dno = b.dno and b.mark='取'
        end
    end
    else 
    if exists (select 1 from inserted where mark='存' )
    begin
        update Depositor set remainder = remainder + accessnum
        from Depositor a inner join inserted b on a.dno = b.dno and b.mark='存'
        
    end

    insert into Access
    select * from inserted
end

try