I have run into a problem with a second trigger we are to write regarding the following:
I have just written a stored procedure and stored function that serve to insert a new row into my Orders table. The row update inserts: Ordernum, OrderDate, Customer, Rep, Manufacturer, Product, Qty, and SaleAmount.
I now have to write a trigger that updates my Offices table by adding the amount of the newly added sale. Problem is, not every salesrep has an office assigned to them. I don't understand if I need to have a when clause under 'FOR EACH ROW' which somehow stipulates this, or if I need to stipulate after my SET Sales line. This is my code so far, but unfortunately, it updates all of the offices sales, not just the one that the salesrep belongs to:
CREATE OR REPLACE TRIGGER UpdateOffices
AFTER INSERT ON Orders
FOR EACH ROW
BEGIN
UPDATE Offices
SET Sales = Sales + :NEW.Amount
WHERE Office IN (SELECT RepOffice
FROM Salesreps
WHERE RepOffice IS NOT NULL);
End;
/
SHOW ERRORS
Sales is the name of the column on the Offices table. Amount if the name used in the stored proc.
You've already been advised to add a predicate on Salesreps, e.g. WHERE Salesrep = :NEW.Rep. Why don't you add it to the subquery?
You are going to run into all sorts of problems implementing your solution using this trigger method.
The Office.Sales column value will become stale as soon as amendments to orders are committed to the database. For example, when the price or quantity on an order is changed or deleted.
I would recommend you implement this requirement as a 'Refresh on Commit' Materialized View.
Related
I have been tasked to match a payment file from a bank that has invoices/payments listed on a text file I have imported into a table called Bank. I need to match the invoices to the project/projects that are associated with the invoices - call this table Invoices - which contains every invoice and project we have every had. I want to match the invoices (from Bank) to the project or multiple projects (from Invoices) to another table - called Report - so I can reconcile the payment file. I can get the correct results from Bank and Invoices with the following query
SELECT invoice
FROM Invoices INV
INNER JOIN Bank as BANK
ON INV.Invoice = BANK.Invoice_Number
The Bank file has 100 invoices and I get 169 invoices on this query. But when I try and do and update or insert
Update Report
set Invoice_Num =
(SELECT invoice
FROM Invoices INV
INNER JOIN Bank as BANK
ON INV.Invoice = BANK.Invoice_Number)
I get 0 rows updated.
I have tried to copy the Bank table to the Report table with
Insert into Report(Invoice_Num)
select Invoice_Number from Bank
but can't figure out how to account for the projects that have duplicated invoices when they are found. Of course I might be going at this entirely wrong and someone has a better way entirely.
Thanks!
Does your Report table have anything in to start with? If not, your UPDATE statement will update 0 rows, because there are 0 rows there to update. (Also, with your code as it stands, note that it would update every entry there to have the same, indeterminate value; I don't think that's what you intend.)
If you just want to copy the invoice numbers from Bank to Report, but leave out any duplicates, then your final bit of SQL just needs a DISTINCT added to do that:
Insert into Report(Invoice_Num)
select DISTINCT Invoice_Number from Bank
If you're trying to put in only invoice numbers from Bank that also match Invoice, then your first bit of code almost works, but needs to be an INSERT, not an UPDATE:
INSERT INTO report (invoice_number)
SELECT invoice
FROM Invoices INV
INNER JOIN Bank as BANK
ON INV.Invoice = BANK.Invoice_Number
Again, if you're also dealing with potential duplicates invoice numbers you only want in Report once, make that a SELECT DISTINCT to avoid them.
If anyone could even just help me phrase this question better I'd appreciate it.
I have a SQL Server table, let's call it cars, which contains entries representing items and information about their owners including car_id, owner_accountNumber, owner_numCars.
We're using a system that sorts 'importantness of owner' based on number of cars owned, and relies on the owner_numCars column to do so. I'd rather not adjust this, if reasonably possible.
Is there a way I can update owner_numCars per owner_accountNumber using a stored procedure? Maybe some other more efficient way I can accomplish every owner_numCars containing the count of entries per owner_accountNumber?
Right now the only way I can think to do this is to (from the c# application):
SELECT owner_accountNumber, COUNT(*)
FROM mytable
GROUP BY owner_accountNumber;
and then foreach row returned by that query
UPDATE mytable
SET owner_numCars = <count result>
WHERE owner_accountNumber = <accountNumber result>
But this seems wildly inefficient compared to having the server handle the logic and updates.
Edit - Thanks for all the help. I know this isn't really a well set up database, but it's what I have to work with. I appreciate everyone's input and advice.
This solution takes into account that you want to keep the owner_numCars column in the CARs table and that the column should always be accurate in real time.
I'm defining table CARS as a table with attributes about cars including it's current owner. The number of cars owned by the current owner is de-normalized into this table. Say I, LAS, own three cars, then there are three entries in table CARS, as such:
car_id owner_accountNumber owner_numCars
1 LAS1 3
2 LAS1 3
3 LAS1 3
For owner_numCars to be used as an importance factor in a live interface, you'd need to update owner_numCars for every car every time LAS1 sells or buys a car or is removed from or added to a row.
Note you need to update CARS for both the old and new owners. If Sam buys car1, both Sam's and LAS' totals need to be updated.
You can use this procedure to update the rows. This SP is very context sensitive. It needs to be called after rows have been deleted or inserted for the deleted or inserted owner. When an owner is updated, it needs to be called for both the old and new owners.
To update real time as accounts change owners:
create procedure update_car_count
#p_acct nvarchar(50) -- use your actual datatype here
AS
update CARS
set owner_numCars = (select count(*) from CARS where owner_accountNumber = #p_acct)
where owner_accountNumber = #p_acct;
GO
To update all account_owners:
create procedure update_car_count_all
AS
update C
set owner_numCars = (select count(*) from CARS where owner_acctNumber = C.owner_acctNumber)
from CARS C
GO
I think what you need is a View. If you don't know, a View is a virtual table that displays/calculates data from a real table that is continously updated as the table data updates. So if you want to see your table with owner_numCars added you could do:
SELECT a.*, b.owner_numCars
from mytable as a
inner join
(SELECT owner_accountNumber, COUNT(*) as owner_numCars
FROM mytable
GROUP BY owner_accountNumber) as b
on a.owner_accountNumber = b.owner_accountNumber
You'd want to remove the owner_numCars column from the real table since you don't need to actually store that data on each row. If you can't remove it you can replace a.* with an explicit list of all the fields except owner_numCars.
You don't want to run SQL to update this value. What if it doesn't run for a long time? What if someone loads a lot of data and then runs the score and finds a guy that has 100 cars counts as a zero b/c the update didn't run. Data should only live in 1 place, updating has it living in 2. You want a view that pulls this value from the tables as it is needed.
CREATE VIEW vOwnersInfo
AS
SELECT o.*,
ISNULL(c.Cnt,0) AS Cnt
FROM OWNERS o
LEFT JOIN
(SELECT OwnerId,
COUNT(1) AS Cnt
FROM Cars
GROUP BY OwnerId) AS c
ON o.OwnerId = c.OwnerId
There are a lot of ways of doing this. Here is one way using COUNT() OVER window function and an updatable Common Table Expression [CTE]. That you won't have to worry about relating data back, ids etc.
;WITH cteCarCounts AS (
SELECT
owner_accountNumber
,owner_numCars
,NewNumberOfCars = COUNT(*) OVER (PARTITION BY owner_accountNumber)
FROM
MyTable
)
UPDATE cteCarCounts
SET owner_numCars = NewNumberOfCars
However, from a design perspective I would raise the question of whether this value (owner_numCars) should be on this table or on what I assume would be the owner table.
Rominus did make a good point of using a view if you want the data to always reflect the current value. You could also use also do it with a table valued function which could be more performant than a view. But if you are simply showing it then you could simply do something like this:
SELECT
owner_accountNumber
,owner_numCars = COUNT(*) OVER (PARTITION BY owner_accountNumber)
FROM
MyTable
By adding a where clause to either the CTE or the SELECT statement you will effectively limit your dataset and the solution should remain fast. E.g.
WHERE owner_accountNumber = #owner_accountNumber
I have a table called INVOICE which stores bill information about an order/orders, one of the columns in this table is a column named paid which is a type of bit. As its name indicates, this column indicates whether the specific order/orders bill is paid or not.
I have another table named RECEIPT, this table stores information about any payment processes for a specific invoice.
So every time user pay an amount for the specified invoice, a new receipt record is created.
Now What I'm trying to do is to create a trigger that updates the paid column in the INVOICE table and set it to 1. This update process should be triggered in case of that the sum of receipts that belong to the invoice is equal to the amount_due in the INVOICE table.
In other words, if invoice due amount= 100$
and the user paid 50$
then, late he paid the other 50$
The paid column in the INVOICE table should be set to 1 as the total payments are equal to the invoice due amount
This is the trigger I've created to achieve the above
CREATE TRIGGER tg_invoice_payment ON RECEIPT
AFTER INSERT
AS
BEGIN
UPDATE INVOICE
SET paid = 1
WHERE INVOICE.invoice_id = (SELECT inserted.invoice_id FROM inserted)
AND (SELECT SUM(RECEIPT.amount_paid)
FROM RECEIPT
JOIN inserted ON RECEIPT.receipt_id = inserted.receipt_id
WHERE RECEIPT.invoice_id = inserted.invoice_id) = (SELECT INVOICE.amount_due
FROM INVOICE
JOIN inserted ON INVOICE.invoice_id = inserted.invoice_id
WHERE INVOICE.invoice_id = inserted.invoice_id)
END;
it compiled successfully but at run time I've get the below error:
The target table 'RECEIPT' of the DML statement cannot have any enabled triggers if the statement contains an OUTPUT clause without INTO clause
I think personally that you should update the paid status outside the scope of triggers. If you perform an INSERT into RECEIPT, you can execute the UPDATE INVOICE ... statement right after that (inside a TRANSACTION of course). A lot cleaner and predictable that way.
As to the error you are getting it's hard to say what is causing that based on the information you gave us. Perhaps the TRIGGER is triggering other TRIGGERs that produce the error you are getting? The statement you provided simply doesn't have an OUTPUT statement.
In any case, the statement you provided is not written correctly (as Damien pointed out) because the inserted table can have multipe rows. This is a rewrite to correct at least that part:
CREATE TRIGGER tg_invoice_payment ON RECEIPT
AFTER INSERT
AS
BEGIN
UPDATE
INVOICE
SET
paid = 1
FROM
inserted AS ins
INNER JOIN INVOICE AS inv ON
inv.invoice_id=ins.invoice_id
WHERE
inv.amount_due=(
SELECT
SUM(r.amount_paid)
FROM
RECEIPT AS r
WHERE
r.receipt_id=ins.invoice_id
);
END;
But as I mentioned earlier you probably not be doing this from a TRIGGER. Execute this statement from your program right after any INSERT/UPDATE. Alternatively, write a Stored Procedure for inserting into RECEIPT and execute the UPDATE statement right after the INSERT.
I am very new to SQL and SQL server, would appreciate any help with the following problem.
I am trying to update a share price table with new prices.
The table has three columns: share code, date, price.
The share code + date = PK
As you can imagine, if you have thousands of share codes and 10 years' data for each, the table can get very big. So I have created a separate table called a share ID table, and use a share ID instead in the first table (I was reliably informed this would speed up the query, as searching by integer is faster than string).
So, to summarise, I have two tables as follows:
Table 1 = Share_code_ID (int), Date, Price
Table 2 = Share_code_ID (int), Share_name (string)
So let's say I want to update the table/s with today's price for share ZZZ. I need to:
Look for the Share_code_ID corresponding to 'ZZZ' in table 2
If it is found, update table 1 with the new price for that date, using the Share_code_ID I just found
If the Share_code_ID is not found, update both tables
Let's ignore for now how the Share_code_ID is generated for a new code, I'll worry about that later.
I'm trying to use a merge query loosely based on the following structure, but have no idea what I am doing:
MERGE INTO [Table 1]
USING (VALUES (1,23-May-2013,1000)) AS SOURCE (Share_code_ID,Date,Price)
{ SEEMS LIKE THERE SHOULD BE AN INNER JOIN HERE OR SOMETHING }
ON Table 2 = 'ZZZ'
WHEN MATCHED THEN UPDATE SET Table 1.Price = 1000
WHEN NOT MATCHED THEN INSERT { TO BOTH TABLES }
Any help would be appreciated.
http://msdn.microsoft.com/library/bb510625(v=sql.100).aspx
You use Table1 for target table and Table2 for source table
You want to do action, when given ID is not found in Table2 - in the source table
In the documentation, that you had read already, that corresponds to the clause
WHEN NOT MATCHED BY SOURCE ... THEN <merge_matched>
and the latter corresponds to
<merge_matched>::=
{ UPDATE SET <set_clause> | DELETE }
Ergo, you cannot insert into source-table there.
You could use triggers for auto-insertion, when you insert something in Table1, but that will not be able to insert proper Shared_Name - trigger just won't know it.
So you have two options i guess.
1) make T-SQL code block - look for Stored Procedures. I think there also is a construct to execute anonymous code block in MS SQ, like EXECUTE BLOCK command in Firebird SQL Server, but i don't know it for sure.
2) create updatable SQL VIEW, joining Table1 and Table2 to show last most current date, so that when you insert a row in this view the view's on-insert trigger would actually insert rows to both tables. And when you would update the data in the view, the on-update trigger would modify the data.
Ok I have a question and it is probably very easy but I can not find the solution.
I have 3 tables plus one main tbl.
tbl_1 - tbl_1Name_id
tbl_2- tbl_2Name_id
tbl_3 - tbl_3Name_id
I want to connect the Name_id fields to the main tbl fields below.
main_tbl
___________
tbl_1Name_id
tbl_2Name_id
tbl_3Name_id
Main tbl has a Unique Key for these fields and in the other table, fields they are normal fields NOT NULL.
What I would like to do is that any time when the record is entered in tbl_1, tbl_2 or tbl_3, the value from the main table shows in that field, or other way.
Also I have the relationship Many to one, one being the main tbl of course.
I have a feeling this should be very simple but can not get it to work.
Take a look at SQL Server triggers. This will allow you to perform an action when a record is inserted into any one of those tables.
If you provide some more information like:
An example of an insert
The resulting change you would like
to see as a result of that insert
I can try and give you some more details.
UPDATE
Based on your new comments I suspect that you are working with a denormalized database schema. Below is how I would suggest you structure your tables in the Employee-Medical visit scenario you discussed:
Employee
--------
EmployeeId
fName
lName
EmployeeMedicalVisit
--------------------
VisitId
EmployeeId
Date
Cost
Some important things:
Note that I am not entering the
employees name into the
EmployeeMedicalVisit table, just the EmployeeId. This
helps to maintain data integrity and
complies with First Normal Form
You should read up on 1st, 2nd and
3rd normal forms. Database
normalization is a very imporant
subject and it will make your life
easier if you can grasp them.
With the above structure, when an employee visited a medical office you would insert a record into EmployeeMedicalVisit. To select all medical visits for an employee you would use the query below:
SELECT e.fName, e.lName
FROM Employee e
INNER JOIN EmployeeMedicalVisit as emv
ON e.EployeeId = emv.EmployeeId
Hope this helps!
Here is a sample trigger that may show you waht you need to have:
Create trigger mytabletrigger ON mytable
For INSERT
AS
INSERT MYOTHERTABLE (MytableId, insertdate)
select mytableid, getdate() from inserted
In a trigger you have two psuedotables available, inserted and deleted. The inserted table constains the data that is being inserted into the table you have the trigger on including any autogenerated id. That is how you get the data to the other table assuming you don't need other data at the same time. YOu can get other data from system stored procuders or joins to other tables but not from a form in the application.
If you do need other data that isn't available in a trigger (such as other values from a form, then you need to write a sttored procedure to insert to one table and return the id value through an output clause or using scope_identity() and then use that data to build the insert for the next table.