问题
For example: A user should not be able to perform INSERT
, DELETE
and UPDATE
operations more than X number of times on a particular table at a given point of time, if the user performs an operation X+1 times than a trigger will be launched.
回答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
来源:https://stackoverflow.com/questions/60375074/setup-a-trigger-on-table-to-limit-the-number-of-insert-delete-update-operation