i want an update trigger an a specific field. if that field value is changed i want to insert into a different table selecting all values of the row where update was made even though it was just for one field .
example
id--------value1--------value2
1-----------abc ----------efg
if value1 is updated to hij, i want to select id(1), value1(hij) and value2(efg) and insert into a different table.
i cannot do inserted.Id or inserted.value2 since both fields are not updated.
NOTE: please note only 1 field is updated, other field values are the same before and after, in my question i have just used an example, but in real life a record will be inserted and i am expected to insert the same values onto a different table. but upon insert the record wont be approved until later when approved field value is changed thats when i am expected the bring the values from other fields to different table.
In your UPDATE trigger, you have access to the Deleted and Inserted pseudo tables which contain the old values (before the UPDATE) and the new ones after the UPDATE.
So you should be able to write something like this:
CREATE TRIGGER trg_Updated
ON dbo.YourTableName
FOR UPDATE
AS
INSERT INTO dbo.ThisOtherTableOfYours(Id, Value1, Value2)
SELECT
i.Id, i.Value1, i.Value2
FROM
Inserted i
INNER JOIN
Deleted d ON i.Id = d.Id
WHERE
i.Value1 <> d.Value1
The SELECT basically joins the two pseudo tables with the old and new values, and selects those rows which have a difference in the Value1 column.
From those columns, the new values after the update are being inserted into your other table. And the Inserted table does contain ALL columns (with their new values) from your table - not just those that have been actually updated - ALL of them!
You should use a simple trigger:
create or replace trigger NAME on TABLENAME after update as
if :new.value1 = 'hij'{
insert into OTHERTABLE (id, value1, value2) values (:old.id, :old.value1, :old.value2);
}
Related
I have table 1.
I have another empty table 2 with the following columns.
I want to insert into table 2 by selecting from table 1 - so I write the query as:
insert into table2(employee,id,zone,url)
select employee, id, zone, concat('https://',employee,'.com/',id,'?',zone)
from table1
Now my table 2 looks like this,
Now for the authcode column, I do the following and insert it into the table2.
insert into table2(authcode)
SELECT CONVERT(VARCHAR(10),HASHBYTES('MD5', substring(URL,8,100)),2)
from table2.
But the insert happens differently like this AS AN ENTIRE NEW SET OF ROWS.
Can someone help me to insert the last column to the corresponding rows instead of it creating a new one?
What you should be doing is UPDATE the table to fill the column authcode, but you could do it all in 1 step while you are inserting the rows:
insert into table2(employee,id,zone,url, authcode)
select
employee,
id,
zone,
concat('https://',employee,'.com/',id,'?',zone),
CONVERT(VARCHAR(10),HASHBYTES('MD5', substring(concat('https://',employee,'.com/',id,'?',zone),8,100)),2)
from table1
or if you want to update:
update table2
set authcode = CONVERT(VARCHAR(10),HASHBYTES('MD5', substring(URL,8,100)),2)
where authcode is null
The result you are seeing is the intended behavior for an INSERT statement. It will always insert new rows.
If you want to modify existing rows your need to use an UPDATE statement.
You can either modify your INSERT to look like what #forpas has posted to get all this work done in one step. Another option is to modify the second INSERT to be an UPDATE like the following:
update table2
set authcode = CONVERT(VARCHAR(10),HASHBYTES('MD5', substring(URL,8,100)),2)
I have the following table
Data --Table name
ID -- Identity column
PCode -- Postal Code
I created the following trigger:
CREATE TRIGGER Trig
ON Data
FOR INSERT
AS
BEGIN
Select * from inserted
END
And inserted the following values
INSERT INTO Data VALUES (125)
INSERT INTO Data VALUES (126)
INSERT INTO Data VALUES (127)
It shows this:
But I was expecting something like this:
After the 1st insertion, the trigger is executed -> one row is shown in the inserted table.
After the 2nd insertion, the trigger is executed -> two rows are shown in the inserted table.
After the 3rd insertion, the trigger is executed -> three rows are shown in the inserted table.
According to msdn.microsoft all the rows inserted are in this table.
How can I access the inserted table so that I can see all the expected rows and not separately?
You can not. From the Use the inserted and deleted Tables article on microsoft.com, you can read:
The inserted table stores copies of the affected rows during INSERT and UPDATE statements.
That means that the inserted table will only contain rows for the current INSERT or UPDATE statement.
If you do want to see all rows for several such INSERT or UPDATE statements, you will have to store these rows in a table you created yourself.
There are 2 table available in a trigger, the inserted and the deleted. Each update on table XXX is actually a delete row X from XXX then an insert of row X in table XXX. So the inserted inside the trigger is a copy of what got inserted. You can do a lot with a trigger, but triggers are dangerous.
For example, on a performance gig, I found a huge SP being run by a trigger, we dropped it and the database came back online. Or another example, if you do a trigger wrong to audit logins, you can down the server.
As TT mentioned, if you want to see all the inserted records then you need to change your Trigger to something like this:
CREATE TRIGGER Trig
ON Data
FOR INSERT
AS
BEGIN
Select * into "tablename"
from
(Select * from inserted) Ins
END
I have a table that looks like the below table:
Every time the user loan a book a new record is inserted.
The data in this table is derived or taken from another table which has no dates.
I need to update this tables based on the records in the other table: Meaning I only need to update this table based on what changes.
Example: Lets say the user return the book Starship Troopers and the book return is indicated to Yes.
How do I update just that column?
What I have tried:
I tried using the MERGE Statement but it works only with unique rows of data, meaning you get an error if the same ID appears more than once.
I also tried using a basic UPDATE Statement and a JOIN but that's not going well.
I am asking because I have ran out of ideas.
Thanks for reading
If you need to update BooksReturn in target table based on the same column in source table
UPDATE t
SET t.booksreturn = s.booksreturn
FROM target t JOIN source s
ON t.userid = s.userid
AND t.booksloaned = s.booksloaned
Here is SQLFiddle demo
You can do this by simple Update & Insert statement.....
Two table A & B
From B you want to insert data into A if not exists other wise Update that data....
,First Insert into temp table....
SELECT *
INTO #MYTEMP
FROM B
WHERE BOOKSLOANED NOT IN (SELECT BOOKSLOANED
FROM A)
,Second Check data and insert into A.
INSERT INTO A
SELECT *
FROM #MYTEMP
And at last write one simple update statement which update all data of A. If any change then it also reflect to that data otherwise data as it is.
You can also update from #MYTEMP table.
I am trying to figure out which i need to use here: deleted, inserted or updated.
basically.
I need to write some data to the history table, when the main table is updated, and only if the status changes from something to either pending or active.
This is what I have now:
ALTER TRIGGER [dbo].[trg_SourceHistory] ON [dbo].[tblSource]
FOR UPDATE AS
DECLARE #statusOldValue char(1)
DECLARE #statusNewValue char(1)
SELECT #statusOldValue = statusCode FROM deleted
SELECT #statusNewValue= statusCode FROM updated
IF (#statusOldValue <> #statusNewValue) AND
(#statusOldValue = 'P' or #statusOldValue = 'A')
BEGIN TRY
INSERT * INTO tblHistoryTable)
select * from [DELETED]
so I want the new data to stay in the main table, the the history table to be updated with what is being overwritten... right now it just copies the same info over. so after update, both my tables have the same data.
There are only the Inserted and Deleted pseudo tables - there's no Updated.
For an UPDATE, Inserted contains the new values (after the update) while Deleted contains the old values before the update.
Also be aware that the triggers is fired once per batch - not once for each row. So both pseudo tables will potentially contain multiple rows! Don't just assume a single row and assign this to a variable - this
SELECT #statusOldValue = statusCode FROM deleted
SELECT #statusNewValue= statusCode FROM updated
will fail if you have multiple rows ! You need to write your triggers in such a fashion that they work with multiple rows in Inserted and Deleted !
Update: yes - there IS a much better way to write this:
ALTER TRIGGER [dbo].[trg_SourceHistory] ON [dbo].[tblSource]
FOR UPDATE
AS
INSERT INTO dbo.tblHistoryTable(Col1, Col2, Col3, ...., ColN)
SELECT Col1, COl2, Col3, ..... ColN
FROM Deleted d
INNER JOIN Inserted i ON i.PrimaryKey = d.PrimaryKey
WHERE i.statusCode <> d.statusCode
AND d.statusCode IN ('A', 'P')
Basically:
explicitly specify the columns you want to insert - both in the INSERT statement as well as the SELECT statement retrieving the data to insert - to avoid any nasty surprises
create an INNER JOIN between Inserted and Deleted pseudo-tables to get all rows that were updated
specify all other conditions (different status codes etc.) in the WHERE clause of the SELECT
This solution works for batches of rows being updated - it won't fail on a multi-row update....
You need to use both the inserted and deleted tables together to check for records that:
1. Already existed (to check it's not an insert)
2. Still exists (to check it's not a delete)
3. The Status field changed
You also need to make sure you do that in a set based approach, as per marc_s's answer, triggers are not single record processes.
INSERT INTO
tblHistoryTable
SELECT
deleted.*
FROM
inserted
INNER JOIN
deleted
ON inserted.PrimaryKey = deleted.PrimaryKey
WHERE
inserted.StatusCode <> deleted.StatusCode
AND (inserted.StatusCode = 'P' OR inserted.StatusCode = 'A')
inserted = the new values
deleted = the old values
There is no updated table, you are looking for inserted.
I want to write a trigger in SQL Server to insert 2 rows into table2 when a row is inserted into table1. I want to use a column value from table1.
So my trigger looks like this
create trigger triggername on table1
as
begin
insert into
insert into
end
How do I get the value of any column from the last inserted row (the row insertion which fires the trigger). I.e. the equivalent of 'referencing row' in oracle
Triggers in SQL Server fire per statement not per row. There are two pseudo tables inserted and deleted that you can use (for an insert trigger the only one of interest is inserted)
CREATE TRIGGER YourTrigger ON Table1
FOR INSERT
AS
INSERT INTO Table2
SELECT * from inserted /*This will contain multiple rows if it is a multi-row insert*/
hi
i have the solution myself. i missed the alias
select #patient_no=fldL1BasCode from inserted
should be
select #patient_no=i.fldL1BasCode from inserted i