8uABJXmZ

1/* Create MyTable.DateAdded w/ constraint if it doesn't already exist */
2IF COL_LENGTH('MyTable', 'DateAdded') IS NULL
3BEGIN
4	ALTER TABLE MyTable
5	ADD [DateAdded] [datetime] NULL;
6	
7	ALTER TABLE MyTable
8	ADD CONSTRAINT [DF_MyTable_DateAdded] DEFAULT (getdate()) FOR [DateAdded];
9END
10GO
11
12/* Create MyTable.DateAdded w/ constraint if it doesn't already exist */
13IF COL_LENGTH('MyTable', 'DateUpdated') IS NULL
14BEGIN
15	ALTER TABLE MyTable
16	ADD [DateUpdated] [datetime] NULL;
17	
18	ALTER TABLE MyTable
19	ADD CONSTRAINT [DF_MyTable_DateUpdated] DEFAULT (getdate()) FOR [DateUpdated];
20END
21GO
22
23/* Drop trigger if it already exists */
24DROP TRIGGER IF EXISTS UpdateDateUpdated_MyTable
25GO
26
27/* Create trigger */
28CREATE TRIGGER UpdateDateUpdated_MyTable
29ON MyTable
30AFTER UPDATE
31AS
32BEGIN
33	IF NOT UPDATE(DateUpdated)
34	BEGIN
35		UPDATE t
36		SET t.DateUpdated = CURRENT_TIMESTAMP
37		FROM MyTable AS t INNER JOIN inserted AS i
38		ON t.OrderID = i.OrderID;
39	END
40END
41GO