在表上设置触发器以限制INSERT，DELETE，UPDATE操作的数量

Question

例如：在给定的时间点，用户在特定表上执行INSERT，DELETE和UPDATE的次数不应超过X次，如果用户执行操作[[X + 1次，则将触发一个触发器。

Answer 1

create table dbo.targetTable
(
    id int,
    colA varchar(10)
);
go
create or alter trigger dbo.DMLxTimes on dbo.targetTable
for insert, update, delete
as
begin
    /*
        --old days..
        IF @@ROWCOUNT > 5
        begin
            rollback;
        end
    --*/

    declare @maxrows int = 5; --maximum number of rows allowed per dml action

    if 
    (select count(*) from inserted) > @maxrows
    or
    (select count(*) from deleted) > @maxrows
    begin
        rollback;
    end
end
go

insert into dbo.targetTable(id, colA)
values (0, 'a'),(0, 'a'),(0, 'a'),(0, 'a'),(0, 'a'); --5 rows inserted
go
insert into dbo.targetTable(id, colA)
values (0, 'a'),(0, 'a'),(0, 'a'),(0, 'a'),(0, 'a'),(0, 'a'); --6 rows inserted ... error
go
insert into dbo.targetTable(id, colA)
values (0, 'a'),(0, 'a'); --2 rows inserted
go

--all updated, error
update dbo.targetTable
set colA = colA;
go

--ok
update top(5) dbo.targetTable
set colA = colA;
go

delete top (4) from dbo.targetTable;
go

--ok
update top(15) dbo.targetTable
set colA = colA;
go