Be gentle, I'm a SQL newbie. I have a table named autonumber_settings like this:
Prefix | AutoNumber
SO | 112320
CA | 3542
A whenever a new sales line is created, a stored procedure is called that reads the current autonumber value from the 'SO' row, then increments the number, updates that same row, and return the number back from the stored procedure. The stored procedure is below:
ALTER PROCEDURE [dbo].[GetAutoNumber]
(
#type nvarchar(50) ,
#out nvarchar(50) = '' OUTPUT
)
as
set nocount on
declare #currentvalue nvarchar(50)
declare #prefix nvarchar(10)
if exists (select * from autonumber_settings where lower(autonumber_type) = lower(#type))
begin
select #prefix = isnull(autonumber_prefix,''),#currentvalue=autonumber_currentvalue
from autonumber_settings
where lower(autonumber_type) = lower(#type)
set #currentvalue = #currentvalue + 1
update dbo.autonumber_settings set autonumber_currentvalue = #currentvalue where lower(autonumber_type) = lower(#type)
set #out = cast(#prefix as nvarchar(10)) + cast(#currentvalue as nvarchar(50))
select #out as value
end
else
select '' as value
Now, there is another procedure that accesses the same table that duplicates orders, copying both the header and the lines. On occasion, the duplication results in duplicate line numbers. Here is a piece of that procedure:
BEGIN TRAN
IF exists
(
SELECT *
FROM autonumber_settings
WHERE autonumber_type = 'SalesOrderDetail'
)
BEGIN
SELECT
#prefix = ISNULL(autonumber_prefix,'')
,#current_value=CAST (autonumber_currentvalue AS INTEGER)
FROM autonumber_settings
WHERE autonumber_type = 'SalesOrderDetail'
SET #new_auto_number = #current_value + #number_of_lines
UPDATE dbo.autonumber_settings
SET autonumber_currentvalue = #new_auto_number
WHERE autonumber_type = 'SalesOrderDetail'
END
COMMIT TRAN
Any ideas on why the two procedures don't seem to play well together, occasionally giving the same line numbers created from scratch as lines created by duplication.
This is a race condition or your autonumber assignment. Two executions have the potential to read out the same value before a new one is written back to the database.
The best way to fix this is to use an identity column and let SQL server handle the autonumber assignments.
Barring that you could use sp_getapplock to serialize your access to autonumber_settings.
You could use repeatable read on the selects. That will lock the row and block the other procedure's select until you update the value and commit.
Insert WITH (REPEATABLEREAD,ROWLOCK) after the from clause for each select.
Related
I created this stored procedure to go through all the records in the table comparing the id (primary key) if exists and the records changed, make the necessary changes & update the record.
If the id is not in the table then insert the record. This stored procedure
compiles fine, but doesn't seem to work properly. Does this need a while loop?
ALTER PROCEDURE [dbo].[SMLineUpdate]
(
#id [int],
#Payroll_Id [int],
#ProductCode nvarchar(255),
#Description nvarchar (255),
#Qty nvarchar(255)
)
AS
IF EXISTS (SELECT Id from Smline where #id = Id) BEGIN
update dbo.SmLine
Set [Payroll_Id] = #Payroll_Id
, ProductCode = #ProductCode
, Description = #Description
, Qty = #Qty
END ELSE BEGIN
INSERT INTO SmLine ([Payroll_Id], [ProductCode], [Description], [Qty])
VALUES (#Payroll_Id, #ProductCode, #Description, #Qty)
END
Your update query is missing a where condition
update dbo.SmLine
Set [Payroll_Id] = #Payroll_Id
,ProductCode = #ProductCode
,Description = #Description
,Qty = #Qty
WHERE Id = #Id -- the query missed this where condition
IF EXISTS(SELECT Id from Smline where Id =#id)
BEGIN
update dbo.SmLine
Set [Payroll_Id]= #Payroll_Id
,ProductCode= #ProductCode
,Description = #Description
,Qty = #Qty
WHERE Id = #Id
END
ELSE
BEGIN
INSERT INTO SmLine ([Payroll_Id],[ProductCode],[Description],[Qty])
VALUES (#Payroll_Id,#ProductCode ,#Description,#Qty)
END
Your SP does not meet the requirement of insert multiple records. It works only for a single record update or inserts, you have to pass multiple id's and values respectively for update multiple so use a different approach like XML as an input parameter so u can simply do this operation for multiple by extracting the XML data.
Your update statement lacks a where statement. That is a major 'no-no', as it will (god forbid...) update all lines in the table.
Your insert statement lacks an identity insert, so consider the case where you are trying to update/insert id=5, but by now this line is deleted (not found in the where), and ids are much bigger. you would search for it -- > not find, and insert a new line (say id=101), then look for id=5 again, not find it again, and insert it again (say id=102), and so on... I don't think that's what you intended. Consider a Merge statement (when matched/when not matched) and get the best of both worlds. Also consider not deleting from the table, and instead add an 'IsDeleted' column (which allows 'reviving' a deleted row).
create procedure test
(#TABLE_NAME varchar(20))
as
declare #lastval varchar(10)
set #lastval = right('000000000' + convert(varchar(10),
(select IsNull(max(Serialno), 0) + 1
from #TABLE_NAME)), 10)
return #lastval
end
Now tell me how I could compose or form dynamic SQL with above SQL where I will pass table name to store procedure when call that stored procedure?
How to return #lastval value to its calling environment?
How to call stored procedure test from another stored procedure where I will store the return value ?
Guide me with sample code.
Genearlly, it's best to use an IDENTITY or a SEQUENCE to assign serial numbers. A zero-padded string or other formatting requirements could be added to the table as a computed column based on the underlying serial integer or formatted in the app code. However, both IDENTITY and SEQUENCE may have gaps, such as due to rollbacks or SQL Server service restart.
In cases where an unbroken sequence of serial values is required by business, one can maintan the last assigned values in a table and assign values transactionally. Below is an example that returns the value using an OUTPUT parameter. Although the proc in your question uses the stored proc RETURN value for this purpose, that should only be used to indicate success or failure, not return data.
CREATE TABLE dbo.TableSerialNumber(
TableName sysname NOT NULL
CONSTRAINT PK_SerialNumber PRIMARY KEY
, SerialNumber int NOT NULL
, FormatString nvarchar(20) NULL
);
GO
INSERT INTO dbo.TableSerialNumber VALUES('Invoice', 0, '0000000000');
INSERT INTO dbo.TableSerialNumber VALUES('PurchaseOrder', 0, '0000000000');
GO
CREATE PROC dbo.GetNextSerialNumberForTable
#TableName sysname
, #FormattedSerialNumber varchar(10) OUTPUT
AS
SET NOCOUNT ON;
DECLARE
#SerialNumber int
, #FormatString nvarchar(20);
UPDATE dbo.TableSerialNumber
SET
#SerialNumber = SerialNumber += 1
, #FormatString = FormatString
WHERE TableName = #TableName;
IF ##ROWCOUNT = 0
RAISERROR('Table %s does not exist in dbo.TableSerialNumber', 16, 1, #TableName);
SET #FormattedSerialNumber = CAST(FORMAT(#SerialNumber, #FormatString) AS varchar(10));
GO
--example usage
CREATE PROC dbo.InsertInvoice
#InvoiceData int
AS
SET XACT_ABORT ON;
DECLARE #InvoiceNumber varchar(10);
BEGIN TRY
BEGIN TRAN;
EXECUTE dbo.GetNextSerialNumberForTable
#TableName = N'Invoice'
, #FormattedSerialNumber = #InvoiceNumber OUTPUT;
INSERT INTO dbo.Invoice (InvoiceID, InvoiceData)
VALUES(#InvoiceNumber, #InvoiceData);
SELECT #InvoiceNumber AS InvoiceNumber;
COMMIT;
END TRY
BEGIN CATCH
IF ##TRANCOUNT > 0 ROLLBACK;
THROW;
END CATCH;
GO
I am just new in SQL language and still studying it. I'm having hard time looking for answer on how can I use the stored procedure and insert value into a table.
I have this stored procedure:
CREATE PROCEDURE TestID
AS
SET NOCOUNT ON;
BEGIN
DECLARE #NewID VARCHAR(30),
#GenID INT,
#BrgyCode VARCHAR(5) = '23548'
SET #GenID = (SELECT TOP (1) NextID
FROM dbo.RandomIDs
WHERE IsUsed = 0
ORDER BY RowNumber)
SET #NewID = #BrgyCode + '-' + CAST(#GenID AS VARCHAR (30))
UPDATE dbo.RandomIDs
SET dbo.RandomIDs.IsUsed = 1
WHERE dbo.RandomIDs.NextID = #GenID
SELECT #NewID
END;
and what I'm trying to do is this:
INSERT INTO dbo.Residents([ResidentID], NewResidentID, [ResLogdate],
...
SELECT
[ResidentID],
EXEC TestID ,
[ResLogdate],
....
FROM
source.dbo.Resident;
There is a table dbo.RandomIDs containing random 6 digit non repeating numbers where I'm pulling out the value via the stored procedure and updating the IsUsed column of the table to 1. I'm transferring data from one database to another database and doing some processing on the data while transferring. Part of the processing is generating a new ID with the required format.
But I can't get it to work Sad I've been searching the net for hours now but I'm not getting the information that I need and that the reason for my writing. I hope someone could help me with this.
Thanks,
Darren
your question is little bit confusing, because you have not explained what you want to do. As i got your question, you want to fetch random id from randomids table and after performed some processing on nextid you want to insert it into resident table [newresidentid] and end of the procedure you fetch data from resident table. if i get anything wrong feel free to ask me.
your procedure solution is following.
CREATE PROCEDURE [TestId]
AS
SET NOCOUNT ON;
BEGIN
DECLARE #NEWID NVARCHAR(30)
DECLARE #GENID BIGINT
DECLARE #BRGYCODE VARCHAR(5) = '23548'
DECLARE #COUNT INTEGER
DECLARE #ERR NVARCHAR(20) = 'NO IDS IN RANDOM ID'
SET #COUNT = (SELECT COUNT(NEXTID) FROM RandomIds WHERE [IsUsed] = 0)
SET #GENID = (SELECT TOP(1) [NEXTID] FROM RandomIds WHERE [IsUsed] = 0 ORDER BY [ID] ASC)
--SELECT #GENID AS ID
IF #COUNT = 0
BEGIN
SELECT #ERR AS ERROR
END
ELSE
BEGIN
SET #NEWID = #BRGYCODE + '-' + CAST(#GENID AS varchar(30))
UPDATE RandomIds SET [IsUsed] = 1 WHERE [NextId] = #GENID
INSERT INTO Residents ([NewResidentId] , [ResLogDate] ) VALUES (#NEWID , GETDATE())
SELECT * FROM Residents
END
END
this procedure will fetch data from your randomids table and perform some processing on nextid than after it directs insert it into resident table and if you want to insert some data through user you can use parameter after declaring procedure name
E.G
CREATE PROCEDURE [TESTID]
#PARAM1 DATATYPE,
#PARAM2 DATATYPE
AS
BEGIN
END
I'm not convinced that your requirement is a good one but here is a way to do it.
Bear in mind that concurrent sessions will not be able to read your update until it is committed so you have to kind of "lock" the update so you will get a block until you're going to commit or rollback. This is rubbish for concurrency, but that's a side effect of this requirement.
declare #cap table ( capturedValue int);
declare #GENID int;
update top (1) RandomIds set IsUsed=1
output inserted.NextID into #cap
where IsUsed=0;
set #GENID =(select max( capturedValue) from #cap )
A better way would be to use an IDENTITY or SEQUENCE to solve your problem. This would leave gaps but help concurrency.
When exactly do we use stored procedures with output parameters and when do we use stored procedures without parameters?
I base my question on an example:
Stored procedure with output parameter
CREATE PROCEDURE uspGetContactsCountByCity
#City nvarchar(60),
#ContactsCount int OUT
AS
BEGIN
SELECT #ContactsCount = COUNT(ContactID)
FROM Contacts
WHERE City = #City
END
Stored procedure executing
DECLARE #ContactsTotal INT
EXEC uspGetContactsCountByCity #ContactsCount = #ContactsTotal OUT, #city = 'Berlin'
SELECT #ContactsTotal
Results: 2
Stored procedure without output parameter
CREATE PROCEDURE uspGetContactsCountByCity2
#City nvarchar(60)
AS
BEGIN
SELECT COUNT(ContactID)
FROM Contacts
WHERE City = #City
END
Stored procedure executing:
EXEC uspGetContactsCountByCity2 #city = 'Berlin'
Results: 2
Both procedures return the same result, in same form, so what's the difference?
Basically, the result you're seeing is actually the result of your SELECT at the end of the procedure, which is doing the same thing.
Please take a look at this documentation:
If you specify the OUTPUT keyword for a parameter in the procedure definition, the stored procedure can return the current value of the parameter to the calling program when the stored procedure exits. To save the value of the parameter in a variable that can be used in the calling program, the calling program must use the OUTPUT keyword when executing the stored procedure.
So basically if you would like your stored procedure to just return just a value instead of a data set, you could use the output parameter. For example, let's take the procedures you have given as an example. They both do the same thing, this is why you got the same result. But what about changing a little bit in the first procedure that has the output parameter.
Here's an example:
create table OutputParameter (
ParaName varchar(100)
)
insert into OutputParameter values ('one'), ('two'),('three'),('one')
CREATE PROCEDURE AllDataAndCountWhereOne
#name nvarchar(60),
#count int OUT
as
Begin
SELECT #count = COUNT(*) from OutputParameter
Where ParaName = #name
select Distinct(ParaName) from OutputParameter
End
Declare #TotalCount int
Exec AllDataAndCountWhereOne #count = #TotalCount OUT, #name = 'One'
Select #TotalCount
With this example, you are getting all the distinct stored data in the table, plus getting the count of a given name.
ParaName
--------------------
one
three
two
(3 row(s) affected)
-----------
2
(1 row(s) affected)
This is one way of using the output parameter. You got both the distinct data and the count you wanted without doing extra query after getting the initial data set.
At the end, to answer your question:
Both procedures gives us the same result, in same form, so what's the difference?
You didn't make a difference in your own results, this is why you didn't really notice the difference.
Other Examples:
You could use the OUT parameter in other kinds of procedures. Let's assume that your stored procedure doesn't return anything, it's more like a command to the DB, but you still want a kind of message back, or more specifically a value. Take these two examples:
CREATE PROCEDURE InsertDbAndGetLastInsertedId
--This procedure will insert your name in the database, and return as output parameter the last inserted ID.
#name nvarchar(60),
#LastId int OUT
as
Begin
insert into OutputParameterWithId values (#name);
SELECT #LastId = SCOPE_IDENTITY()
End
or:
CREATE PROCEDURE InsertIntoDbUnlessSomeLogicFails
--This procedure will only insert into the db if name does exist, but there's no more than 5 of it
#name nvarchar(60),
#ErrorMessage varchar(100) OUT
as
Begin
set #ErrorMessage = ''
if ((select count(*) from OutputParameterWithId) = 0)
begin
set #ErrorMessage = 'Name Does Not Exist'
return
end
if ((select count(*) from OutputParameterWithId) = 5)
begin
set #ErrorMessage = 'Already have five'
return
end
insert into OutputParameterWithId values (#name);
End
These are just dummy examples, but just to make the idea more clear.
An example, based on yours would be if you introduced paging to the query.
So the result set is constrained to 10 items, and you use a total count out parameter to drive paging on a grid on screen.
Answer from ozz regarding paging does not make sense because there is no input param that implements a contraint on the number of records returned.
However, to answer the question... the results returned by these stored procedures are not the same. The first returns the record count of contacts in given city in the out param ContactsCount. While the count may also be recieved in the second implement through examining the reader.Rows.Count, the actual records are also made a available. In the first, no records are returned - only the count.
Can we perform Insert/Update/Delete statement with SQL Server Functions. I have tried with but SQL Server error is occured.
Error:
Invalid use of side-effecting or time-dependent operator in 'DELETE' within a function.
AnyBody have any Idea why we can not use Insert/Update/Delete statements with SQL Server functions.
Waiting for your good idea's
No, you cannot.
From SQL Server Books Online:
User-defined functions cannot be used
to perform actions that modify the
database state.
Ref.
Yes, you can!))
Disclaimer: This is not a solution, it is more of a hack to test out something. User-defined functions cannot be used to perform actions that modify the database state.
I found one way to make INSERT, UPDATE or DELETE in function using xp_cmdshell.
So you need just to replace the code inside #sql variable.
CREATE FUNCTION [dbo].[_tmp_func](#orderID NVARCHAR(50))
RETURNS INT
AS
BEGIN
DECLARE #sql varchar(4000), #cmd varchar(4000)
SELECT #sql = 'INSERT INTO _ord (ord_Code) VALUES (''' + #orderID + ''') '
SELECT #cmd = 'sqlcmd -S ' + ##servername +
' -d ' + db_name() + ' -Q "' + #sql + '"'
EXEC master..xp_cmdshell #cmd, 'no_output'
RETURN 1
END
Functions in SQL Server, as in mathematics, can not be used to modify the database. They are intended to be read only and can help developer to implement command-query separation. In other words, asking a question should not change the answer. When your program needs to modify the database use a stored procedure instead.
You can't update tables from a function like you would a stored procedure, but you CAN update table variables.
So for example, you can't do this in your function:
create table MyTable
(
ID int,
column1 varchar(100)
)
update [MyTable]
set column1='My value'
but you can do:
declare #myTable table
(
ID int,
column1 varchar(100)
)
Update #myTable
set column1='My value'
Yes, you can.
However, it requires SQL CLR with EXTERNAL_ACCESS or UNSAFE permission and specifying a connection string. This is obviously not recommended.
For example, using Eval SQL.NET (a SQL CLR which allow to add C# syntax in SQL)
CREATE FUNCTION [dbo].[fn_modify_table_state]
(
#conn VARCHAR(8000) ,
#sql VARCHAR(8000)
)
RETURNS INT
AS
BEGIN
RETURN SQLNET::New('
using(var connection = new SqlConnection(conn))
{
connection.Open();
using(var command = new SqlCommand(sql, connection))
{
return command.ExecuteNonQuery();
}
}
').ValueString('conn', #conn).ValueString('sql', #sql).EvalReadAccessInt()
END
GO
DECLARE #conn VARCHAR(8000) = 'Data Source=XPS8700;Initial Catalog=SqlServerEval_Debug;Integrated Security=True'
DECLARE #sql VARCHAR(8000) = 'UPDATE [Table_1] SET Value = -1 WHERE Name = ''zzz'''
DECLARE #rowAffecteds INT = dbo.fn_modify_table_state(#conn, #sql)
Documentation: Modify table state within a SQL Function
Disclaimer: I'm the owner of the project Eval SQL.NET
You can have a table variable as a return type and then update or insert on a table based on that output.
In other words, you can set the variable output as the original table, make the modifications and then do an insert to the original table from function output.
It is a little hack but if you insert the #output_table from the original table and then say for example:
Insert into my_table
select * from my_function
then you can achieve the result.
We can't say that it is possible of not their is some other way exist to perform update operation in user-defined Function. Directly DML is not possible in UDF it is for sure.
Below Query is working perfectly:
create table testTbl
(
id int identity(1,1) Not null,
name nvarchar(100)
)
GO
insert into testTbl values('ajay'),('amit'),('akhil')
Go
create function tblValued()
returns Table
as
return (select * from testTbl where id = 1)
Go
update tblValued() set name ='ajay sharma' where id = 1
Go
select * from testTbl
Go
"Functions have only READ-ONLY Database Access"
If DML operations would be allowed in functions then function would be prety similar to stored Procedure.
No, you can not do Insert/Update/Delete.
Functions only work with select statements. And it has only READ-ONLY Database Access.
In addition:
Functions compile every time.
Functions must return a value or result.
Functions only work with input parameters.
Try and catch statements are not used in functions.
CREATE FUNCTION dbo.UdfGetProductsScrapStatus
(
#ScrapComLevel INT
)
RETURNS #ResultTable TABLE
(
ProductName VARCHAR(50), ScrapQty FLOAT, ScrapReasonDef VARCHAR(100), ScrapStatus VARCHAR(50)
) AS BEGIN
INSERT INTO #ResultTable
SELECT PR.Name, SUM([ScrappedQty]), SC.Name, NULL
FROM [Production].[WorkOrder] AS WO
INNER JOIN
Production.Product AS PR
ON Pr.ProductID = WO.ProductID
INNER JOIN Production.ScrapReason AS SC
ON SC.ScrapReasonID = WO.ScrapReasonID
WHERE WO.ScrapReasonID IS NOT NULL
GROUP BY PR.Name, SC.Name
UPDATE #ResultTable
SET ScrapStatus =
CASE WHEN ScrapQty > #ScrapComLevel THEN 'Critical'
ELSE 'Normal'
END
RETURN
END
Functions are not meant to be used that way, if you wish to perform data change you can just create a Stored Proc for that.
if you need to run the delete/insert/update you could also run dynamic statements. i.e.:
declare
#v_dynDelete NVARCHAR(500);
SET #v_dynDelete = 'DELETE some_table;';
EXEC #v_dynDelete
Just another alternative using sp_executesql (tested only in SQL 2016).
As previous posts noticed, atomicity must be handled elsewhere.
CREATE FUNCTION [dbo].[fn_get_service_version_checksum2]
(
#ServiceId INT
)
RETURNS INT
AS
BEGIN
DECLARE #Checksum INT;
SELECT #Checksum = dbo.fn_get_service_version(#ServiceId);
DECLARE #LatestVersion INT = (SELECT MAX(ServiceVersion) FROM [ServiceVersion] WHERE ServiceId = #ServiceId);
-- Check whether the current version already exists and that it's the latest version.
IF EXISTS(SELECT TOP 1 1 FROM [ServiceVersion] WHERE ServiceId = #ServiceId AND [Checksum] = #Checksum AND ServiceVersion = #LatestVersion)
RETURN #LatestVersion;
-- Insert the new version to the table.
EXEC sp_executesql N'
INSERT INTO [ServiceVersion] (ServiceId, ServiceVersion, [Checksum], [Timestamp])
VALUES (#ServiceId, #LatestVersion + 1, #Checksum, GETUTCDATE());',
N'#ServiceId INT = NULL, #LatestVersion INT = NULL, #Checksum INT = NULL',
#ServiceId = #ServiceId,
#LatestVersion = #LatestVersion,
#Checksum = #Checksum
;
RETURN #LatestVersion + 1;
END;