MSSQL Trigger - Updating newly inserted record on INSERT - sql-server

Question

I wish to make a modification (Set Deleted = 1) to rows being inserted into my table CustomerContact if the SELECT statement returns more than 0.
I have the following, but it remains untested:
CREATE TRIGGER mark_cust_contact_deleted ON CustomerContact
AFTER INSERT AS
BEGIN
DECLARE #numrows INT;
/* Determine if order matches criteria for marking customer contact as DELETED immediately */
SELECT #numrows = COUNT(*)
FROM [Order] o
JOIN OrderMeterDetail om
ON o.OrderID = om.OrderID
WHERE o.WorkTypeID = 3 AND o.WorkActionID = 26 AND o.WorkStageID IN (109, 309, 409)
AND om.MeterDetailTypeID = 1 AND om.MeterLocationID IN (2, 4)
AND o.orderid IN (SELECT OrderID FROM INSERTED);
/* If the order matches the criteria, mark the customer contact as deleted */
IF (#numrows >= 1)
UPDATE CustomerContact
SET Deleted = 1
WHERE CustomerContactID IN (SELECT CustomerContactID FROM INSERTED);
END
Within my IF statement, I am using FROM INSERTED, assuming that this will return the newly inserted id for the record that was created by the insert.
I have two questions about this statement:
Will this part of the statement perform an UPDATE just the record
that was just inserted into CustomerContact?
UPDATE CustomerContact
SET Deleted = 1
WHERE CustomerContactID IN (SELECT CustomerContactID FROM INSERTED);
Is this the way that would be deemed correct to make a change to a row that has just been inserted based on the result of a SELECT statement?
CustomerContactID is an auto-incrementing primary key column.

Answer 1

You say "Just the record that was inserted". Inserted can contain more than one record. If there is only one, then your trigger will function as you expect. But if there is more than one, it won't.
I would rewrite your logic into a single update statement along the lines of...
Update CustomerContact
Set Deleted = 1
From CustomerContact
inner join inserted on CustomerContact.CustomerContactID = inserted.CustomerContactID
inner join orders on inserted.OrderID = orders.OrderID
where
-- some criteria.

Answer 2

CREATE TRIGGER mark_cust_contact_deleted ON CustomerContact
AFTER INSERT AS
BEGIN
DECLARE #numrows INT;
/* Determine if order matches criteria for marking customer contact as DELETED immediately */
-- Get all the records into a temp table
SELECT * INTO #Temp
FROM inserted
Declare #ID int;
SELECT #numrows = COUNT(*)
FROM [Order] o
JOIN OrderMeterDetail om
ON o.OrderID = om.OrderID
WHERE o.WorkTypeID = 3 AND o.WorkActionID = 26 AND o.WorkStageID IN (109, 309, 409)
AND om.MeterDetailTypeID = 1 AND om.MeterLocationID IN (2, 4)
AND o.orderid IN (SELECT OrderID FROM #Temp);
IF (#numrows >= 1)
BEGIN
WHILE EXISTS (SELECT TOP 1 * FROM #Temp)
BEGIN
SELECT TOP 1 #ID = ID FROM #Temp
/* If the order matches the criteria, mark the customer contact as deleted */
UPDATE CustomerContact
SET Deleted = 1
WHERE CustomerContactID IN (SELECT CustomerContactID FROM #Temp WHERE ID = #ID);
DELETE FROM #Temp WHERE ID = #ID
END
END
DROP TABLE #Temp
END
I think you can do something like this, tweak the code to futher suit for needs, hope this will help.

Answer 3

Here is the final solution that I used to solve this issue:
CREATE TRIGGER mark_cust_contact_deleted ON CustomerContact
AFTER INSERT AS
BEGIN
UPDATE CustomerContact
SET Deleted = 1
FROM CustomerContact cc
JOIN inserted i
ON cc.CustomerContactID = i.CustomerContactID
JOIN [Order] o
ON i.OrderID = o.OrderID
JOIN OrderMeterDetail om
ON i.OrderID = om.OrderID
WHERE o.WorkTypeID = 3 AND o.WorkActionID = 26 AND o.WorkStageID IN (109, 309, 409)
AND om.MeterDetailTypeID = 1 AND om.MeterLocationID IN (2, 4)
END