Automatically fill row with value based on inserted id - sql

I have a table where the user is able to insert the ID of a Node that corresponds to a title elsewhere in the database. I want this tile to be automatically inserted into the row after the user has chosen the id.
This is my table:
I need to have the "SommerhusNavn" column be automatically filled with values based on the "SommerhusId" inserted.
I am using a third party to handle the CRUD functionality, where the user picks the ID from a dropdown. I already know in which table the title for the ID is located, I'm just not sure how to fill the row with the insert statement. Would I need to run a separate query for this to happen?
Edit:Solution
CREATE TRIGGER [dbo].[BlokeredePerioderInsert]
ON dbo.BlokeredePerioder
AFTER INSERT
AS
BEGIN
SET NOCOUNT ON;
UPDATE BlokeredePerioder SET SommerhusNavn = text FROM umbracoNode AS umbNode
where SommerhusId = umbNode.id
END
GO

Yes, you need to run additional UPDATE query. Let's assume that you have the TitlesTable, with columns ID and Title. Then it should look like:
UPDATE MyTable SET SommerhusNavn = Title FROM TitlesTable AS A
WHERE SommerhusId = A.ID
AND SommerhusNavn IS NOT NULL --not necessary

Perhaps i'm not understanding, but why can't you use send the value across in the initial update?
Can you use a trigger on the database side?
Alternatively, you'll need to send a update across, following the insert.

Related

Is it possible to create and execute 2 triggers on one table

I am trying to find some workaround to create and execute multiple triggers for different tables on one table. I have 2 tables
Person Detail
Address
The way this table is designed is when a user updates Person's address it creates a new record into address table instead of updating the existing one and I want to insert the changes into auditlog table when a user updates person details or address.
I was able to create a trigger for person table but dont know how can i make it work by using or calling multiple triggers on Person Table
Following is the code for Person table update trigger
CREATE TRIGGER [dbo].[tr_tblPersonDetail_ForUpdate]
ON [dbo].[PersonDetail]
FOR Update
AS
BEGIN
Declare #Id int,
Declare #OldFirstName varchar(50), #NewFirstName varchar(50)
BEGIN
Select #Id=personId,#NewFirstName = NewFirstName from Inserted
select #OldFirstName = NewFirstName from deleted where #id = personId
if(#OldFirstName <> #NewFirstName )
Insert into AuditLog values('some value','AfterValue','Before Value')
Yes, one table may have multiple triggers. You do need to exercise caution, however - you may not want every update to fire both triggers, or you may have need to execute the triggers in a particular order.
It really sounds like you want an INSTEAD OF UPDATE trigger for the requirement of
creates a new record into address table instead of updating the existing one
If you need your trigger to execute only if specific field(s) were updated, use UPDATED() to test for them.
You can use sp_settriggerorder to dictate which trigger should execute and which one last.
In your case, I would suggest an AFTER UPDATE for any operation that changes only the person's name, and then an INSTEAD OF UPDATE which handles cases where the address is changed (which will also need to handle the name change).
If you choose to continue down the path of using triggers at all.

How to insert into the table a user name record

I've a table. In this table I have two columns - 'insert_name' and 'modified_name'. I need to insert into this columns data about who has inserted data into the table('insert_name') and who has changed these data in the table (modified_name). How it can be done?
You are looking for basic DML statements.
If your record is already in the table, then you need to UPDATE it. Otherwise, when you are about to add your record to it and it doesn't already exist in the destination table then you are looking for INSERT INTO statement.
Example of updating information for record with first id:
UPDATE yourtable SET insert_name = 'value1', modified_name = 'value2' WHERE id = 1
Example of inserting new record:
INSERT INTO yourtable(id, company_name, product_name, insert_name)
VALUES (1, 'Google', 'PC', 'value1')
If you are looking for automatic changes to those columns then you need to look into triggers.
Remember that more often than not you may find that the application connecting to the database is using single database user in which case you probably know the context within the application itself (who inserts, who updates). This does eliminate triggers and put the task straight on simple insert/update commands from within your application layer.
You might be able to use the CURRENT_USER function to find the name of the user making the change.
The value from this function could then be used to update the appropriate column. This update could be done as part of the INSERT or UPDATE statement. Alternatively use an INSERT or UPDATE trigger.
Personally I avoid triggers if I can.
For those 2 columns add Current_User as Default constraint.
As the first time Insert Statement will save them with current login user names. For update write an Update trigger with the same Current_User statement for the column Modified_Name.
If and only if your application business logic can't update the column modified_nme then only go for Trigger.
See the use of Current_Use
https://msdn.microsoft.com/en-us/library/ms176050.aspx

Change column value after INSERT if the value fits criteria?

I have never really worked with Triggers before in MSSQL but I think it'll be what I need for this task.
The structure of the table is as such:
ID|****|****|****|****|****|****|****|TOUROPERATOR
The Tour Operator Code is the code that tells us what company owned the flight we carried out for them. Two of those codes (there are 24 in total) are outdated. Our users requested that those two be changed but the tour operator code is pulled from a database we don't control. The FlightData table however, we do control. So I was thinking a trigger could change the tour operator code if it was one of the two outdated ones, to the correct ones instead respectively when they were inserted.
So I went into good ol' SQL Management Studio and asked to make a trigger. It gave me some sample code and here is my Pseudo Code below:
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TRIGGER ChangeProvider
ON FlightData
AFTER INSERT
AS
BEGIN
IF(TheInsertedValue == Criteria)
UPDATE FlightData
SET TheInsertedValue = NewValue
ENDIF
END
GO
I am not that good with this type of Database Programming so excuse my mistakes.
How would I go about doing this?
You could add a computed column to your table instead of adding a trigger.
Then the new column could just use a case statement to either show
the original TourOperator column value or the new value you wanted.
You'd add a new column to your table like this
TourOperatorCorrect = CASE WHEN TourOperator = 'Whatever value' THEN 'ChangedValue'
--I just want to use what I have already in the TourOperator column
ELSE TourOperator
END AS VARCHAR(50)
Basics of computed columns are here - https://msdn.microsoft.com/en-ie/library/ms188300.aspx
Your misconception here is that the trigger runs once per inserted value - it is in fact run once per insert statement, so you can and will find more than one row inserted at once.
You'll find that your inserted values are in the pseudo table inserted, which has the same structure as your FlightData table in this case. You write a select statement against that, specifying any criteria you wish.
However, it's not immediately clear what your logic is - does the FlightData table you are updating in your trigger only have one row? Do you update every row in the table with the newest inserted value? It is hard to understand what you are trying to now, and what the purpose of the table and this trigger are - let alone what you would want to do if you inserted more than one row at once.
When inserted table contains mutiple rows,your code will fail,so change code to work with inserted table as whole
UPDATE F
SET f.TheInsertedValue = i.value
from inserted i
join
Flighttable F
on f.matchingcolumn=i.matchingcolumn
and i.somevalue='criteria'

Concat specific string to every inserted row

This is an hypothetical case..
I'm trying to find a good approach to make sure that every value inserted in an specific column col1 of my table mytable has a specific string http:// at the begining of the value.
Example:
I want to insert myprofile into mytable so (after my check condition..) the final value would be http://myprofile
I guess that a good approach could be using a trigger on insert but I didn't find anything concrete yet..
Any ideas?
Thank you.
You can try something like this as a starting point - this is for SQL Server (don't know MySQL well enough to provide that trigger code for you):
-- create the trigger, give it a meaningful name
CREATE TRIGGER PrependHttpPrefix
ON dbo.YourTableName -- it's on a specific table
AFTER INSERT, UPDATE -- it's for a specific operation, or several
AS
BEGIN
-- the newly inserted rows are stored in the "Inserted" pseudo table.
-- It has the exact same structure as your table that this trigger is
-- attached to.
-- SQL Server works in such a way that if the INSERT affected multiple
-- rows, the trigger is called *once* and "Inserted" contains those
-- multiple rows - you need to work with "Inserted" as a multi-row data set
--
-- You need to join the "Inserted" rows to your table (based on the
-- primary key for the table); for those rows newly inserted that
-- **do not** start with "http://" in "YourColumn", you need to set
-- that column value to the fixed text "http:/" plus whatever has been inserted
UPDATE tbl
SET YourColumn = 'http://' + i.YourColumn
FROM dbo.YourTableName tbl
INNER JOIN Inserted i ON tbl.PKColumn = i.PKColumn
WHERE LEFT(i.YourColumn, 7) <> 'http://'
END

How to check if a column is being updated in an INSTEAD OF UPDATE Trigger

I am making some tweaks to a legacy application built on SQL Server 2000, needless to say I only want to do the absolute minimum in the fear that it may just all fall apart.
I have a large table of users, tbUsers, with a BIT flag for IsDeleted. I want to archive off all current and future IsDeleted = 1 user records into my archive table tbDeletedUsers.
Moving the currently deleted users is straight forward, however I want a way to move any future users where the IsDeleted flag is set. I could use a standard AFTER trigger on the column however I plan to add some constraints to the tbUser table that would violate this, what I'd like is for my INSTEAD OF UPDATE trigger to fire and move the record to archive table instead?
I guess my question is... is it possible to trigger an INSTEAD OF UPDATE trigger on the update of an individual column? This is what I have so far:
CREATE TRIGGER trg_ArchiveUsers
INSTEAD OF UPDATE ON tbUsers
AS
BEGIN
...
END
GO
If so an example (SQL 2000 compatible) would be much appreciated!
Using the UPDATE(columnname) test, you can check in a trigger whether a specific column was updated (and then take specific actions), but you can't have a trigger fire only on the update of a specific column. It will fire as soon as the update is performed, regardless of the fact which column was the target of the update.
So, if you think you have to use an INSTEAD OF UPDATE trigger, you'll need to implement two kinds of actions in it:
1) insert into tbDeletedUsers + delete from tbUsers – when IsDeleted is updated (or, more exactly, updated and set to 1);
2) update tbUsers normally – when IsDeleted is not updated (or updated but not set to 1).
Because more than one row can be updated with a single UPDATE instruction, you might also need to take into account that some rows might have IsDeleted set to 1 and others not.
I'm not a big fan of INSTEAD OF triggers, but if I really had to use one for a task like yours, I might omit the UPDATE() test and implement the trigger like this:
CREATE TRIGGER trg_ArchiveUsers
ON tbUsers
INSTEAD OF UPDATE
AS
BEGIN
UPDATE tbUsers
SET
column = INSERTED.column,
…
FROM INSERTED
WHERE INSERTED.key = tbUsers.key
AND INSERTED.IsDeleted = 0
;
DELETE FROM tbUsers
FROM INSERTED
WHERE INSERTED.key = tbUsers.key
AND INSERTED.IsDeleted = 1
;
INSERT INTO tbDeletedUsers (columns)
SELECT columns
FROM INSERTED
WHERE IsDeleted = 1
;
END