I have programmed a function with
1) Create Table in Tempdb
Create Table in Tempdb
Create Table Value
while , If commands
Delete values from Table
Inserting values into above tables
Checking existence of table
IF OBJECT_ID('tempdb..#Results') IS NOT NULL
DROP TABLE #Results
inside of it.
The results are in Temp tables show be backed
can I use a Table Value function for it? or it just should an insert
can I use a Table Value function for it? or it just should an insert
No, DML functions are not allowed inside a function. You need to use a stored procedure to perform the operations you have mentioned.
Read following link for more details on what is allowed and not allowed in a function.
SQL SERVER – User Defined Functions (UDF) Limitations
Related
I have a TABLE A with 3000 records with 25 columns. I want to have a history table called Table A history holding all the changes updates and deletes for me to look up any day. I usually use cursors. Now thought using triggers which I was not asked to. Do you have any other suggestions? Many thanks!
If your using tsql /SQL server and you can't use triggers, which is the only sure way to get every change, maybe use a stored procedure that is scheduled in job to run every x amount of time, the stored procedure using a MERGE statement with the two tables to get new records or changes. I would not suggest this if you need every single change without question.
CREATE TABLE dbo.TableA (id INT, Column1 nvarchar(30))
CREATE TABLE dbo.TableA_History (id INT, Column1 nvarchar(30), TimeStamp DateTime)
(this code isn't production, just the general idea)
Put the following code inside a stored procedure and use a Sql Server Job with a schedule on it.
MERGE INTO dbo.TableA_History
USING dbo.TableA
ON TableA_History.id = TableA.id AND TableA_History.Column1 = TableA.Column1
WHEN NOT MATCHED BY TARGET THEN
INSERT (id,Column1,TimeStamp) VALUES (TableA.id,TableA.Column1,GETDATE())
So basically if the record either doesn't exist or doesn't match meaning a column changed, insert the record into the history table.
It is possible to create history without triggers in some case, even if you are not using SQL Server 2016 and system-versioned table are not available.
In some cases, when you can identify for sure which routines are modifying your table, you can create history using OUTPUT INTO clause.
For example,
INSERT INTO [dbo].[MainTable]
OUTPUT inserted.[]
,...
,'I'
,GETUTCDATE()
,#CurrentUserID
INTO [dbo].[HistoryTable]
SELECT *
FROM ... ;
In routines, when you are using MERGE I like that we can use $action:
Is available only for the MERGE statement. Specifies a column of type
nvarchar(10) in the OUTPUT clause in a MERGE statement that returns
one of three values for each row: 'INSERT', 'UPDATE', or 'DELETE',
according to the action that was performed on that row.
It's very handy that we can add the user which is modifying the table. Using triggers you need to use session context or session variable to pass the user. In versioning table you need to add additional column to the main table in order to log the user as it only logs the current table columns (at least for now).
So, basically it depends on your data and application. If you have many sources of CRUD over the table, the trigger is the most secure way. If your table is very big and heavily used, using MERGE is not good as it my cause blocking and harm performance.
In our databases we are using all of the methods depending on the situation:
triggers for legacy
system-versioning for new development
direct OUTPUT in the history, when sure that data is modified only by given set of routines
I need to maintain some values from one stored procedure and use them again in some other stored procedure.
Below is the part of my stored procedure where I am creating a global temp table.
IF object_id('tempdb..##TempNewSchedule') IS NULL
BEGIN
CREATE TABLE ##TempNewSchedule (OrderId INT)
END
INSERT INTO ##TempNewSchedule
VALUES(#OrderID)
So my requirement is like , whenever this SP will be called it will check if there is already a global temp table or not, If not then it should create a new global temp table , other wise it should insert the record into already created temp table. but every time it creates new temp table.
Please suggest any other approach also.
Thanks
I have a stored procedure to insert a row, with a list of values which came as input parameters, into a table (tmp).
This table mirrors another table (data), and I'm looking for a way to use the same SP to insert a row from data into tmp.
I've seen Pass result of a query into stored procedure, but I can't put INSERT in a UDF.
Is there an easy way, not requiring
a query which puts all the values into variables and sends the variables?
a table-typing or other additions to our already-too-full database
Edit The desired result would be a way to write something like
EXEC sp_insert (SELECT c1,c2,c3 FROM data)
Maybe you can use variable table as the parameter for the SP (search for this)
It needs to define user defined table type , but I'm using this method.
Table used as a parameter can get values from inserting or selecting from other table.
alter procedure sp_insert
#table your_table_type readonly
AS
BEGIN
--here you take a row (maybe the only one) from #table and insert it to TMP
END
Background: I am trying to have an after update trigger which stores the changed values dynamically into another table. Since this trigger should be generic and easy to transfer to other tables and won't cause problems, if I add additional columns (If my whole code should be required to solve this, I'll update the question)
While trying to do this, I encounter following issue: I want to store the inserted table into an temporary table, which I do in this way:
SELECT *
INTO #tempINSERTED
FROM INSERTED
But the original table contains both: ntext and timestamp columns which aren't allowed in temporary tables.
Another approach I tried, was looping through the system table INFORMATION_SCHEMA.COLUMNS and build a SQL statement as a string excluding non-copyable columns, but this way I cannot access the inserted table. - I already figured I cannot access inserted if I use sp_executesql.
So my question: is there a way to access the inserted table and exclude non-copyable columns as ntext, text, image ?
Thanks in advance
You want the triggers to run fast. So the better approach would be to generate the create trigger code rather than looping through the fields in the trigger itself. Then if the table schema changes you will need to regenerate the trigger.
For your #TEMPINSERTED table you can use nvarchar(max) in place of ntext,
varchar(max) for text and varbinary(max) in place of image. You can also use and binary(8) or bigint in place of timestamp.
I would suggest using a table variable instead of an #temptable. I.e.:
declare #tempTable table (
fieldname int, -- and so on
)
I have a problem described as follows: I have a table with one instead of insert trigger:
create table TMessage (ID int identity(1,1), dscp varchar(50))
GO
Alter trigger tr_tmessage on tmessage
instead of insert
as
--Set NoCount On
insert into tmessage
select dscp from inserted
GO
Alter proc P1
As
--Set NoCount On
insert into tmessage
(dscp)
values('some data')
Select SCOPE_IDENTITY()
GO
When I execute P1 it returns Null for SCOPE_IDENTITY() instead of the identity of the table. I even tried Output clause in the insert statement in the proc. but again the output table Identity field that gets filled from inserted in the Output clause is 0 in this case.
Any help would be appreciated.
Well, you've got yourself quite a pickle there.
From the one hand, you need the instead of insert trigger on your table, but from the other hand, you want to get the identity that this trigger generates back to the stored procedure that activated it.
Since there is no way to send parameters to and from triggers, you will have to do one of 3 things:
Find some way to eliminate the need for that instead of trigger.
This is my best recommendation.
Break your stored procedure to 2 parts: One part will do everything until the insert into statement (including it), thus activating the instead of insert trigger, and the other part that will do all operations needed after the trigger. this way you can use the scope_identity() inside the instead of insert trigger and send it's return value to the second stored procedure as a parameter.
Note: this design means you have to insert records one by one. should you try to insert more then one record, scope_identity() will only return the identity of the last row inserted by the trigger.
Find some way of passing data between the stored procedure and the instead of trigger. Since triggers can't except or return parameters, you will have to use either a temporary table or a regular table. This suggested solution is only suggested as a last resort, since it will complicate your code and probably cause some performance issues as well. Also, you will have to find a way to hold execution of the stored procedure until the instead of trigger will finish it's work. I can give you some pointers on how to share data between the procedure and the trigger, but I really suggest not to choose this solution.
SCOPE_IDENTITY() return the value from current scope and that is stored procedure outside from stored procedure it will be null.use ##identity to get last inserted identity.