I have created a DML trigger to capture the data for a table that needs to have track all the data modifications.
I am able to capture the SPID, Hostname, Appname and UserName along with the records changed.
Now, I wanted to capture the DML statement that made the modifications to the records.
For example, I can insert into the table using
Normal Insert statement with values
Insert into table using selecting the records
Using a Merge statement
Similarly, we can have multiple ways to do the other DML operations also like Update and Delete.
I wanted to capture the statement that the user has executed to modify the records.
Is there a way I can get this functionality?
Related
I'm having a little trouble with understanding functions and triggers in sql. I didn't post the code of procedure chkInsertAritcle but let's say it returns NEW if it managed to make change and NULL if it didn't.
So my question is about the trigger. If I put AFTER INSERT does that means that it will complete INSERT without depending on the return value? And what
happens with the rest of the rows?
Next question is if I put BEFORE INSERT, in what order does code runs?
Thanks!
CREATE TRIGGER ArticleIns
AFTER INSERT ON ListOfArticles
FOR EACH ROW
EXECUTE PROCEDURE chkInsertArticle();
First all BEFORE triggers run in alphabetical order, then the operation is performed, then all AFTER triggers run in alphabetical order.
Each operation sees the result of the previous one as input, and if any trigger returns NULL, processing for that row stops. So if a BEFORE trigger returns NULL, the DML operation won't take place.
This happens independently for each row affected by the triggering DML statement.
So if the trigger runs before insert, then the code runs before the data is inserted into the row and constraints are checked. So for example you might want to add a timestamp before the data is committed to the database,
If it runs after then the data is already present in the table and all constraints have been checked. This is usually where you want to trigger another process based on the row data, maybe update another table, send an e-mail etc.
In your example, the data will be in the database before your procedure runs. So if your procedure modifies the row data, it needs to be in the database.
I have a database in which I want to make a centralized trigger; if any database table is hit with an insert, update or delete operation, then this trigger should be executed and column values that are inserted, updated or deleted from that operation should be saved in my own table by the help of trigger.
I have seen fn_dblog function in SQL Server but it does not return column values which are affected. I need to save that column values also which are going to be inserted or updated.
Looking for ideas on how to write a trigger that will delete a record when a condition is met.
I have some records being written to a SQL Server 2008 database table. These records that are being written are not important and I would like to see them removed. There are two columns that will have unique information when these records are written and I would like a trigger to remove them as soon as they are written.
I could run a daily job to delete all records that equal X and Y but my thought why not delete the records as they are written.
What would this kind of trigger look like?
If you are not able to change that at any app layer you can use an INSTEAD OF INSERT trigger and those rows will not even be inserted at all.
It will save the database from both inserting and deleting.
I need a sql statement, to insert a new row in one database table and update an existing row in another database table based on some conditions.
Is there a way to do this? To insert a row in one table and update a row in another database table in one sql statement?
Thanks in advance!
Yes, they are called Transactions, and are implemented with START TRANSACTION and COMMIT/ROLLBACK with something like:
START TRANSACTION;
INSERT INTO ...
UPDATE table2 SET name='TOTO' WHERE type=1;
COMMIT;
EDIT
This is not in fact one SQL query, but the operation is done atomically - and I think that is what you need.
A single SQL statement allows you to update one table, not several; if that statement is a MERGE then you can specify insert/update/delete actions but still targeting just the same one target table.
If you just want consistency, use transactions; until a transaction is committed, changes within it are not visible to the outside world.
If you want that a single update (which you cannot control) resulted in a coordinated insert, use an on update trigger in the table being updated. The trigger would insert appropriate row(s) into other table(s).
You can use Trigger to update second table on insert of first table
Yes, it's possible with stored procedures.
Watch this: Stored procedures
I am trying to find impact of doing DDL statement against deleted and inserted logical tables inside table trigger. I have:
CREATE TRIGGER [Trigger52]
ON [dbo].[Table1]
FOR DELETE, INSERT, UPDATE
AS
BEGIN
create table inserted (c1 int)
select * from inserted
END
When it is triggered, I expected to get an error. Instead, it seems to ignore create table statement entirely and select rows that have been inserted.
Is there a documentation describing this behavior or explanation?
Inside triggers there are always two pseudo-tables existing: inserted and deleted. See Using the inserted and deleted Tables:
SQL Server automatically creates and
manages these tables. You can use
these temporary, memory-resident
tables to test the effects of certain
data modifications and to set
conditions for DML trigger actions.
You cannot directly modify the data in
the tables or perform data definition
language (DDL) operations on the
tables.