Select child tables and update by sql trigger on parent after update -related to SQL Server 2008 r2

Here's one way of doing it ...

IF OBJECT_ID('Update_table_1','TR') is not null
	DROP TRIGGER Update_table_1
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TRIGGER Update_table_1
	ON  [table 1] AFTER UPDATE  
AS 
BEGIN
	SET NOCOUNT ON;
	
	-- identify child tables of this table ([table 1]) that have a column isLocked
	-- NB we know the name of the parent table as that's the one we're putting the trigger on :-)
	-- Alternatively you could maintain a table with these relationships defined and just query that
	select C.name 
	into #children 
	from sysforeignkeys A
	join syscolumns B on A.fkeyid=B.id and A.fkey=B.colid
	join sysobjects C on A.fkeyid=C.id
	where rkeyid = (select id from sysobjects where name = 'table 1')
	and fkeyid in (select id from syscolumns where  name = 'id')

	declare @tname varchar(50)	-- table name
	declare @sql varchar(1024)	-- dynamic sql statement
	declare @id int			-- id of a row changed on [table 1]
	
	-- step through all of the child tables building up the sql to update them
	declare cur1 cursor for
		SELECT name from #children
	open cur1
	fetch next from cur1 into @tname
	while @@FETCH_STATUS = 0
	begin
			-- step through the keys of the changed rows
			declare curkeys cursor for
				select id from inserted	-- inserted table contains all the rows affected by the update
				-- replace "id" with the pk column name on table 1
			open curkeys
			fetch next curkeys into @id
			while @@FETCH_STATUS = 0
			begin
				-- replace "id" here with the fk column name on child tables
				set @sql = 'update ' + @tname + ' set isLocked = 1 where id = ' + @id
				exec(@sql)
				fetch next from curkeys into @id
			end
			close curkeys
			deallocate curkeys
		fetch next from cur1 into @tname
	end
	drop table #children
	close cur1
	deallocate cur1
END

If the child tables have different column names as the foreign keys "pointing" back to the parent then you can find out what those column names are with something similar to this ...

DECLARE @ForId varchar(200)
SET @ForId = (select COLUMN_NAME from INFORMATION_SCHEMA.KEY_COLUMN_USAGE
    WHERE CONSTRAINT_NAME LIKE 'FK%' AND TABLE_NAME = @tname)
PRINT @ForId

and then change the dynamic sql to something like

@sql = 'update ' + @tname + ' set isLocked = 1 where ' + @ForId + ' = ' + @id

I didn't amend the sql above as it was easier just to show you how you can get this info.
Note that this will only work if you have a single-column primary key on your tables - now that you know the name of the sql view Google can provide more complex examples if you need them.
Also note that information_schema is a better approach than using sysobjects (or sys.objects for later versions) as it is less likely to change.