Use trigger after multiple insert to update log table - sql

Question

I have the following trigger:
ALTER TRIGGER [Staging].[tr_UriData_ForInsert]
ON [Staging].[UriData]
FOR INSERT
AS
BEGIN
DECLARE #_Serial NVARCHAR(50)
DECLARE #_Count AS INT
IF ##ROWCOUNT = 0
RETURN
SET NOCOUNT ON;
IF EXISTS(SELECT * FROM inserted)
BEGIN
SELECT #_Count = COUNT(Id) FROM inserted
SELECT #_Serial = SerialNumber FROM inserted
INSERT INTO [Staging].[DataLog]
VALUES (CURRENT_TIMESTAMP, #_Serial + ': Data Insert --> Rows inserted: ' + #_Count, 'New data has been received')
END
END
The table receives multiple rows at once. I want to be able to add one row in the log table to tell me the insert has happened.
It works great with one row being inserted, but with multiple rows, the trigger doesn't fire. I have read other items on here and it is quite clear that you shouldn't use ROW_NUMBER().
In summary: I want to update my log table when a multiple row insert happens in another table called UriData.
The data is inserted from C# using the following:
using (var sqlBulk = new SqlBulkCopy(conn, SqlBulkCopyOptions.Default, transaction))
{
sqlBulk.DestinationTableName = tableName;
try
{
sqlBulk.WriteToServer(dt);
}
catch(SqlException sqlEx)
{
transaction.Rollback();
var msg = sqlEx.Message;
return false;
}
finally {
transaction.Commit();
conn.Close();
}
}
I don't want to know what is being inserted, but when it has happened, so I can run a set of SPROCS to clean and pivot the data.
TIA

Answer 1

The problem is your trigger assumes that only one row will be updated. A scalar variable can only have 1 value. So, for example, the statement SELECT #_Serial = SerialNumber FROM inserted will set #_Serial with the last value returned from the object inserted.
Treat your data as what it is, a dataset. This is untested, however, I suspect this gives you the result you want:
ALTER TRIGGER [Staging].[tr_UriData_ForInsert]
ON [Staging].[UriData]
FOR INSERT
AS
BEGIN
--No need for a ROWCOUNT. If there are no rows, then nothing was inserted, and this trigger won't happen.
INSERT INTO [Staging].[DataLog] ({COLUMNS LIST})
SELECT CURRENT_TIMESTAMP,
SerialNumber + ': Data Insert --> Rows inserted: ' +
CONVERT(varchar(10),COUNT(SerialNumber) OVER (PARTITION BY SerialNumber)), --COUNT returns an INT, so this statement would have failed with a conversion error too
'New data has been received'
FROM inserted;
END
Please note my comments or sections in braces ({}).
Edit: Sean, who has since deleted his answer, used GROUP BY. I copied what exact method you had, however, GROUP BY might well be the clause you want, rather than OVER.

Answer 2

So after a lot of digging and arguing, my hosting company told me that they have disabled bulk inserts of any kind, without bothering to notify their customers.