I want to write a stored procedure (SQL server 2008r2), say I have a table:
person
Columns:
Id int (pk)
Date_of_birth date not null
Phone int allow null
Address int allow null
Name nvarchat(50) not null
Sample data:
Id=1,Date_of_birth=01/01/1987,phone=88888888,address=null,name='Steve'
Update statement in Stored procedure, assume
The parameters are already declare:
Update person set
Date_of_birth=#dob,phone=#phone,address=#address,name=#name where id=#id
The table has a trigger to log any changes.
Now I have an asp.net update page for updating the above person table
The question is, if user just want to update address='apple street' , the above update statement will update all the fields but not check if the original value = new value, then ignore this field and then check the next field. So my log table will log all the event even the columns are not going to be updated.
At this point, my solutions
Select all the value by id and store them into local variables.
Using if-else check and generate the update statement. At last,
dynamically run the generated SQL (sp_executesql)
Select all the value by id and store them into local variables.
Using if-else check and update each field seperately:
If #dob <> #ori_dob
Begin
Update person set date_of_birth=#dob where id=#id
End
May be this is a stupid question but please advice me if you have better idea, thanks!
This is an answer to a comment by the OP and does not address the original question. It would, however, be a rather ugly comment.
You can use a statement like this to find the changes to Address within an UPDATE trigger:
select i.Id, d.Address as OldAddress, i.Address as NewAddress
from inserted as i inner join
deleted as d on d.Id = i.Id
where d.Address <> i.Address
One such statement would be needed for each column that you want to log.
You could accumulate the results of the SELECTs into a single table variable, then summarize the results for each Id. Or you can use INSERT/SELECT to save the results directly to your log table.
Related
I have this question that I can see what it's asking but just can't wrap my head around how to write it specifically:
When a new tuple is inserted into the sales order detail, your trigger should insert a corresponding raw material tuple in the Inventory Report table for the Report date (i.e., beginning inventory level, consumption quantity, same-day order quantity, next-day order quantity)
Assumptions I gathered from the notes:
itemID = itemID from RAWMATERIALS table
reportDate = dueDate from SALESORDERS table
begInv = inventoryLevels from RAWMATERIALS table
consumpQty = itemID from FINISHEDGOODS * rmQuantity (raw material required to make each finished good) from FINISHED GOODS
orderNextDay = If consumpQty <= begInv then orderNextDay = consumpQty
orderSameDay = 0
orderSameDay = If consumpQty > begInv then orderNextDay = begInv
orderSameDay = consumpQty - begInv
I thought the trigger might go something like:
CREATE OR REPLACE TRIGGER inv_report
BEFORE INSERT
ON SALESORDERDETAIL
FOR EACH ROW
DECLARE
item_id RAWMATERIALS.ITEMID%TYPE
reportDate SALESORDERS.DUEDATE%TYPE
begInv RAWMATERIALS.INVENTORYLEVEL%TYPE
And then I understand we would probably need to INSERT into INVENTORYREPORT table (which currently has no data in it) and maybe do an IF ELSEIF statement to satisfy the orderNextDay and orderSameDay columns but i'm still not familiar enough with PL/SQL to know exactly how to tackle this.
Can anyone help me out with this? Thanks!
I'll try to find some time to write up some code for you on this, but my first recommendation is to NOT do this in a trigger. Instead, create a procedure "insert_so_detail" that inserts into the the SALESORDERDETAIL and then does the related insert into INVENTORYREPORT.
That procedure is then always called to insert into the S-O-D table. Executing DML inside triggers is a tricky thing to do because the database might decide it needs to restart the DML and then possibly do another insert into the I-R table. Check out this AskTOM thread for more details.
You are always better off putting your DML into PL/SQL package APIs, then only allow DML on the table through the API (grant execute on the package, do NOT grant insert or update or delete on the table directly to a user).
I am testing the trigger named, "tulockout" listed below, with this alter statement..."alter user testuser account lock;" to see if the trigger log a record of what happened in table, "log_table_changes".
However, certain values are not accurately logging into the table, "log_table_changes". To be specific v_dusr.start_dt is returning NULL when the trigger, "tulockout" fires off after I execute "alter user testuser account lock;" statement.
I am not certain as to why. Can you please assist?
How can I fix this issue? Thanks.
create or replace trigger tulockout
after alter on schema
declare
cursor v_abc is
select du.username, max(us.start_dt)
from dba_users du, user_session us, users_info ui
where ui.db_user_name = du.username
and ui.db_user_name = us.user_name
and ui.db_user_name = ora_login_user;
v_dusr v_abc%ROWTYPE;
begin
if(ora_sysevent = 'ALTER' and v_dusr.username = ora_dict_obj_name and
v_dusr.account_status = 'LOCKED') then
insert into log_table_changes(username,
lastlogin_date,
notes,
execute_date,
script_name
)
values(
v_dusr.username,
v_dusr.start_dt,
ora_dict_obj_type||', '||
ora_dict_obj_name||' has been locked out.',
sysdate,
ora_sysevent
);
end;
You are declaring a cursor, and a record based on that; but you don't ever execute the cursor query or populate the variable.
Your cursor query is currently missing a group-by clause so will error when run, because of the aggregate function. You don't really need to include the user name in the select list though, as you already know that value. You are, though, later referring to the v_duser.account_status field, which doesn't exist in your cursor query/rowtype, so you need to add (and group by) that too.
The trigger also needs to be at database, not schema, level; and unless you intend to record who performed the alter command, you don't ned to refer to ora_login_user - looking that user's status up doesn't seem very helpful.
You don't really need a cursor at all; a select-into would do, something like (assuming there will always be a row returned from the joins to your user_session and users_info tables; which implies they store the username in the same case as dba_users does - although I'm not sure why you are joining to users_info at all?):
create or replace trigger tulockout
after alter on database
declare
v_start_dt user_session.start_dt%TYPE;
v_account_status dba_users.account_status%TYPE;
begin
select du.account_status, max(us.start_dt)
into v_account_status, v_start_dt
from dba_users du
join user_session us on us.db_user_name = du.username
-- join not needed?
-- join users_info ui on ui.db_user_name = us.user_name
where du.username = ora_dict_obj_name
group by du.account_status;
if(ora_sysevent = 'ALTER' and ora_dict_obj_type = 'USER'
and v_account_status = 'LOCKED') then
insert ...
and then use those date and status variables and ora_dict_obj_name(the user that was altered) in the insert.
I've also switched to modern join syntax, and tweaked the conditions a bit.
Untested, but should give you the idea.
You could make it even easier by doing a single insert ... select against those tables, removing the need for local variables.
I am trying to build a simple hotel room check-in database as a learning exercise.
CREATE TABLE HotelReservations
(
roomNum INTEGER NOT NULL,
arrival DATE NOT NULL,
departure DATE NOT NULL,
guestName CHAR(30) NOT NULL,
CONSTRAINT timeTraveler CHECK (arrival < departure) /* stops time travelers*/
/* CONSTRAINT multipleReservations CHECK (my question is about this) */
PRIMARY KEY (roomNum, arrival)
);
I am having trouble specifying a constraint that doesn't allow inserting a new reservation for a room that has not yet been vacated. For example (below), guest 'B' checks into room 123 before 'A' checks out.
INSERT INTO HotelStays(roomNum, arrival, departure, guestName)
VALUES
(123, date("2017-02-02"), date("2017-02-06"), 'A'),
(123, date("2017-02-04"), date("2017-02-08"), 'B');
This shouldn't be allowed but I am unsure how to write this constraint. My first attempt was to write a subquery in check, but I had trouble figuring out the proper subquery because I don't know how to access the 'roomNum' value of a new insert to perform the subquery with. I then also figured out that most SQL systems don't even allow subquerying inside of check.
So how am I supposed to write this constraint? I read some about triggers which seem like it might solve this problem, but is that really the only way to do it? Or am I just dense and missing an obvious way to write the constraint?
The documentation indeed says:
The expression of a CHECK constraint may not contain a subquery.
While it would be possible to create a user-defined function that goes back to the database and queries the table, the only reasonable way to implement this constraint is with a trigger.
There is a special mechanism to access the new row inside the trigger:
Both the WHEN clause and the trigger actions may access elements of the row being inserted, deleted or updated using references of the form "NEW.column-name" and "OLD.column-name", where column-name is the name of a column from the table that the trigger is associated with.
CREATE TRIGGER multiple_reservations_check
BEFORE INSERT ON HotelReservations
BEGIN
SELECT RAISE(FAIL, "reservations overlap")
FROM HotelReservations
WHERE roomNum = NEW.roomNum
AND departure > NEW.arrival
AND arrival < NEW.departure;
END;
I'm having some issues using checkboxes in combination with an insert/update statement. As it stands, I have a report of available credit cards, with a checkbox next to each row. The user can select as many as they like to approve, then hit a submit button to have their profile updated. This is where I am stuck.
I would like to have a single PSQL process that will update the user profile table based on whether or not said credit card is there. If it doesn't exist, then we insert all relevant information. If it already is there, all I want to do is update that record by changing 'Approved_flag' to 'Y'. I've written this code chunk, which inserts new records and it works fine:
FOR i in 1..APEX_APPLICATION.G_F01.count
LOOP
INSERT INTO ls_credit_cards(credit_card_id, created_by, created_on, card_id, user_id, approved_flag)
VALUES (apex_application.g_f01(i), :F125_USER_ID,sysdate, :P58_CARDS, :P58_USER, 'Y');
END LOOP;
I understand that ORACLE doesn't support the usual if/else commands, so I've researched this a bit and found that I should probably be using the MERGE command, but everything I've seen makes it use two tables. All I'm using is one, with all data being taken from the report/check boxes so I'm kind of at a loss here. Can I still use the MERGE command in this instance, or is there something else that would serve my purposes better?
You can use MERGE. You just need to select your data from `DUAL'
MERGE INTO ls_credit_cards dest
USING( SELECT apex_application.g_f01(i) credit_card_id,
:F125_USER_ID created_by,
sysdate created_on,
:P58_CARDS card_id,
:P58_USER user_id,
'Y' approved_flag
FROM dual) src
ON( dest.credit_card_id = src.credit_card_id )
WHEN MATCHED
THEN
UPDATE SET dest.approved_flag = src.approved_flag
WHEN NOT MATCHED
THEN
INSERT( credit_card_id,
created_by,
created_on,
card_id,
user_id,
approved_flag )
VALUES( src.credit_card_id,
src.created_by,
src.created_on,
src.card_id,
src.user_id,
src.approved_flag );
I'm unable to retrieve the latest inserted id from my SQL Server 2000 db using a typed dataset in asp.NET
I have created a tableadapter and I ticked the "Refresh datatable" and "Generate Insert, Update and Delete statements". This auto-generates the Fill and GetData methods, and the Insert, Update, Select and Delete statements.
I have tried every possible solution in this thread
http://forums.asp.net/t/990365.aspx
but I'm still unsuccesfull, it always returns 1(=number of affected rows).
I do not want to create a seperate insert method as the auto-generated insertCommand perfectly suits my needs.
As suggested in the thread above, I have tried to update the InsertCommand SQL syntax to add SELECT SCOPY_IDENTITY() or something similar, I have tried to add a parameter of type ReturnValue, but all I get is the number of affected rows.
Does anyone has a different take on this?
Thanks in advance!
Stijn
I decided to give up, I can't afford to waste any more time on this.
I use the Insert statement after which I do a select MAX(id) query to hget the insert ID
If anyone should have a solution, I'll be glad to read it here
Thanks
Stijn
I successfully found a way to get the incremental id after insert using my table adapter.
My approach is a little different, I'm using a Store procedure to make the insert, so my insert command has all the values but the ID, I made the sp return the ID just calling:
SET #ID=SCOPE_IDENTITY()
and then
COMMIT TRAN
and last line will be
RETURN #ID
Then I searched my table adapter parameters for InsertCommand and set the #RETURNVALUE to the column of the incremental ID of the table, so when it's executed automatically put the return value on the id field.
Hope this help
You need to tell your table's table-adapter to refresh the
data-table after update/insert operation.
This is how you can do that.
Open the properties of TableAdapter -> Default Select Query -> Advnaced options. and Check the option of Refresh the data table. Save the adapter now. Now when you call update on table-adapter, the data-table will be updated [refreshed] after the update/insert operation and will reflect the latest values from database table. if the primary-key or any coloumn is set to auto-increment, the data-table will have those latest value post recent update.
Now you can Call the update as TableAdapterObj.Update(ds.dataTable);
Read latest values from the DataTable(ds.dataTable) coloumns and assign respective values into the child table before update/insert. This will work exactly the way you want.
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