alter trigger EmpIns
on Emp for delete
as
begin
     rollback;
end

delete from emp;
select * from emp;
//nie daje usunac
-----------------------------------------
create trigger EmpInss
on Emp for insert
as
begin
     update emp set
	 comm=0
	 where comm is null;
end

insert into emp(empno, ename, comm)values
(2322, 'Kowalski',120),
(2323,'Kowalski2',NULL)

select * from emp;
//zmienia wszystki znaczenia w kolumnie comm na 0(zero);
-------------------------------------------------------------------
create trigger EmpInsUpd
on Emp for insert
as
begin
    --inserted,deleted
	select*from inserted;--widzimy ktore dane byly wstawione
	if EXISTS(select 1 from inserted where sal<1000)
	Begin
	    declare @TempTable table
		(
		id int identity primary key,
		Empno varchar(20)
		);
		insert into @TempTable(Empno)
		select Empno, SAL from inserted;

		Declare @MinId int = (select min(id) from @TempTable);
		Declare @MaxId int = (select max(id) from @TempTable);
		while(@MinId<=@MaxId)
		 begin
		 if EXISTS(Select 1 from @TempTable where SAL<1000 and id= @MinId)
		 begin
		  declare @Empno varchar(30)
		  update emp set
		  sal = (select sal from emp deleted where empno = @Empno)
		  where empno =@Empno
		  end
		  set @MinId = @MinId+1;
		  end

	end
end

update emp set sal=sal-100;

select * from emp;
----------------------------------------------------------------------------------------
CREATE TRIGGER T6Z6
ON EMP FOR INSERT, UPDATE, DELETE
AS
BEGIN
	IF EXISTS(SELECT 1 FROM INSERTED WHERE INSERTED.ENAME != ENAME)
	BEGIN
		ROLLBACK;
	END
	IF EXISTS(SELECT 1 FROM INSERTED WHERE EXISTS (SELECT ENAME FROM EMP
	WHERE INSERTED.ENAME = ENAME))
	BEGIN
		ROLLBACK;
	END
	IF NOT EXISTS(SELECT 1 FROM INSERTED WHERE SAL > 0)
	BEGIN
		ROLLBACK;
	END
END

INSERT INTO EMP(EMPNO, ENAME, COMM, SAL)
VALUES(2325, 'Kowalski', 120, 1900);

DELETE FROM EMP
WHERE SAL > 0;

UPDATE EMP
SET ENAME = 'Zmiennik';

SELECT * FROM EMP;