I would like to create a function that returns a column based on input from three other columns. As temporary tables are not allowed within functions, is it possible to create a table variable from three input columns?
CREATE FUNCTION dbo.convert_value(
#CustomerID VARCHAR(MAX),
#CustomerValue VARCHAR(MAX),
#CustomerDescription VARCHAR(MAX)
)
RETURNS FLOAT
AS BEGIN
DECLARE #CustomerTable TABLE (
UniquePatientUID VARCHAR(MAX),
ResultValue VARCHAR(MAX),
PracticeDescription VARCHAR(MAX)
);
-- How can I insert #UniquePatientUID, #ResultValue and #PracticeDescription into #CustomerTable
END
The context of this question is that I have a SQL script that uses temporary tables and many UPDATE and ALTER TABLE statements, that I need to convert into a function. That script begins with the three columns mentioned, and adds a fourth column, Converted_Value, which is calculated with several hundred lines of code and manipulating temporary tables. Is there any hope here?
A table variable insert is really not different than a regular insert. Don't use temp tables. You can alter the table as well, or just declare it initially with that fourth column and allow it to be NULL.
INSERT INTO #CustomerTable (UniquePatientUID, ResultValue, PracticeDescription)
VALUES(#CustomerID, #CustomerValue, #CustomerDescription);
Don't forget to return the FLOAT.
Table Variable is a table so, you can just use INSERT INTO ... VALUES....
INSERT INTO #CustomerTable (UniquePatientUID,ResultValue,PracticeDescription )
VALUES
(#UniquePatientUID, #ResultValue , #PracticeDescription)
Unless you need a table variable for some specific reason, why not just work with the variables as a derived table expression? i.e.
;with inputs (UniquePatientUID, ResultValue, PracticeDescription) as
(
select #UniquePatientUID, #ResultValue, #PracticeDescription
)
select *
from inputs
Table variables fall out of scope after the function call, and you can't pass table types in or out of functions either. So really all a table variable does here is serve as a means of place keeping that's more familiar to SQL developers. But they're not free, which is the only reason I'm curious what your use case is.
If you don't need to return them as a set or something similar, you can just interact with the variables directly too.
Related
How do I pass multiple entries through an input parameter mapped from a Table Function in SAP HANA ?
I've written a Table Function with an Input Parameter say IN_FORMAT_CD.
I've mapped this parameter to the one created in my calculation view.
I'm able to retrieve the data when I'm passing only one value say 100.
But it gives no result when I'm passing more than one value.
Is there any workaround for the same ?
My table function :
FUNCTION "HADMIN"."RA.Test.Prathamesh::PH_DEMO" (IN IN_FORMAT_CD NVARCHAR(500))
RETURNS TABLE (NAME NVARCHAR(10), ID NVARCHAR(10), FORMAT_CD NVARCHAR(3))
LANGUAGE SQLSCRIPT
SQL SECURITY INVOKER AS
BEGIN
RETURN
SELECT NAME,ID,FORMAT_CD
FROM
HADMIN.PH_DEMO
WHERE FORMAT_CD IN (select :IN_FORMAT_CD as FORMAT_CD from dummy);
END;
What you are looking for is the APPLY_FILTER function of SAP HANA SQLScript.
The following example shows how your scenario could be coded:
create function get_vals (IN id_list varchar(400))
returns table (id bigint, val varchar(40))
as
begin
declare myfilter varchar(450) := ' ID in (' || :id_list || ')';
_tmp = select id, val from some_vals;
_tmp2 = APPLY_FILTER (:_tmp, :myfilter);
return :_tmp2;
end;
select *
from
get_vals ('1, 4, 23, 4, 23, 3');
This approach will push down the unique list of IDs to be used as a filter when reading the table data. However, this is still dynamic SQL so you lose benefits like plan sharing and risk SQL injection attacks. Read more on this e.g. here.
If possible, you want to handle selection lists in your application code.
This, in turn, would also give you the option to decide whether using IN-lists or inner joins against temporary tables is the best approach for your situation.
In case you want to go with the selection list as a string, you should at least make sure, that common SQL injection attacks are not used and that the "in-list" really only contains possible ID values and commas.
it is not possible to produce(!) many items from a single sql variable unless you split them
In your SQL subselect query will return only rows that FORMAT_CD column values are exactly same with IN_FORMAT_CD parameter.
If this parameter represents more than one value, then this parameter is a concatenated string representation of each sub items. So we can split them back.
Splitting will produce a table on the fly which can be used for selection.
Please create the user-defined HANA Split function fnsplit that source codes can be found at referenced document
Then you can alter your function as follows assuming that each value is seperated with "," from others
ALTER FUNCTION "HADMIN"."RA.Test.Prathamesh::PH_DEMO" (IN IN_FORMAT_CD NVARCHAR(500))
RETURNS TABLE (NAME NVARCHAR(10), ID NVARCHAR(10), FORMAT_CD NVARCHAR(3))
LANGUAGE SQLSCRIPT
SQL SECURITY INVOKER AS
BEGIN
RETURN
SELECT NAME,ID,FORMAT_CD
FROM
HADMIN.PH_DEMO
WHERE FORMAT_CD IN (
select str from fnsplit(:IN_FORMAT_CD,',')
);
END;
In a SQL Server database, one can use table variables like this:
declare #table as table (a int)
In an Azure Data Warehouse, that throws an error.
Parse error at line: 1, column: 19: Incorrect syntax near 'table'
In an Azure Data Warehouse, you can use temporary tables:
create table #table (a int)
but not inside functions.
Msg 2772, Level 16, State 1, Line 6 Cannot access temporary tables
from within a function.
This document from Microsoft says,
◦Must be declared in two steps (rather than inline): ◾CREATE TYPE
my_type AS TABLE ...; , then ◾DECLARE #mytablevariable my_type;.
But when I try this:
create type t as table (a int);
drop type t;
I get this :
Msg 103010, Level 16, State 1, Line 1 Parse error at line: 1, column:
8: Incorrect syntax near 'type'.
My objective is to have a function in an Azure Data Warehouse which uses a temporary table. Is it achievable?
Edit Start Here
Note that I am not looking for other ways to create one specific function. I have actually done that and moved on. I'm a veteran programmer but an Azure Data Warehouse rookie. I want to know if it's possible to incorporate some concept of temporary tables in an Azure Data Warehouse function.
Ok, I believe this is what you are after.
Firstly, this uses a Table Value Function, which are significantly faster than Scalar or Multi-statement Table value Functions.
Secondly, there was no use for a Table Variable, or Temporary Table, just some good odd string manipulation, a bit of maths, and a CTE. Definitely no expensive WHILE loop.
I've tested this against the examples in the link, and they all return the expected values.
USE Sandbox;
GO
CREATE FUNCTION ValidateHealthNumber (#HealthNumber varchar(10))
RETURNS TABLE
AS
RETURN
WITH Doubles AS(
SELECT CONVERT(tinyint,SUBSTRING(V.HN,O.P,1)) AS HNDigit,
CONVERT(tinyint,SUBSTRING(V.HN,O.P,1)) * CASE WHEN O.P % 2 = 0 THEN 1 ELSE 2 END ToAdd
FROM (VALUES(#HealthNumber)) V(HN)
CROSS APPLY (VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9)) O(P)),
Parts AS (
SELECT CONVERT(tinyint,SUBSTRING(CONVERT(varchar(2),ToAdd),1,1)) AS FirstDigit, --We know that the highest value can be 18 (2*9)
CONVERT(tinyint,SUBSTRING(CONVERT(varchar(2),ToAdd),2,1)) AS SecondDigit --so no need for more than 2 digits.
FROM Doubles)
SELECT CASE RIGHT(#HealthNumber, 1) WHEN 10 - RIGHT(SUM(FirstDigit + SecondDigit),1) THEN 1 ELSE 0 END AS IsValid
FROM Parts;
GO
CREATE TABLE #Sample(HealthNumber varchar(10));
INSERT INTO #Sample
VALUES ('9876543217'), --Sample
('5322369835'), --Valid
('7089771195'), --Valid
('8108876957'), --Valid
('4395667779'), --Valid
('6983806917'), --Valid
('2790412845'), --not Valid
('5762696912'); --not Valid
SELECT *
FROM #Sample S
CROSS APPLY ValidateHealthNumber(HealthNumber) VHN;
GO
DROP TABLE #Sample
DROP FUNCTION ValidateHealthNumber;
If you don't understand any of this, please do ask.
No you can't. Object can't be created inside User Defined Functions (UDF). Use table variables instead.
If you want yo use user defined type, first create it outside the UDF and use it as a variable type within the UDF.
-- Create the data type
CREATE TYPE TestType AS TABLE
(
Id INT NOT NULL,
Col1 VARCHAR(20) NOT NULL)
GO
-- Create the tabled valued function
CREATE FUNCTION TestFunction
()
RETURNS
#Results TABLE
(Result1 INT, Result2 INT)
AS
BEGIN
-- Fill the table variable with the rows for your result set
DECLARE #Var1 TestType;
RETURN
END
GO
So, I have this stored procedure (let's call it SP1) that gets as parameters two strings (say string1 and string2)
However, I need to call this stored procedure a lot from my code, so in order to make things faster, I was thinking of doing it in bulk. Collecting all of the parameters into a collection of some sort, and then send this.
From what I understand I need to use a DataTable on the code side, and a custom table type as the parameter on the SQL Server side - ok, cool. But...now what?
But... how do I get from there to the point where I actually go
EXEC SP1 string1, string2 or something along those lines?
Not sure whether this is what you like to achieve, instead of parsing those two string parameters, you would like to get a table holding all of the string row?
If so, you could you use UDF within SP,
Check here:
CREATE FUNCTION [dbo].[Name]
(
#parameter
)
RETURNS #Table TABLE
(
col1 varchar(50),
col2 varchar(50)
)
AS
BEGIN
**the query that inserts each records to TABLE**
END
Then using this [Name] UDF in your SP
Create a table type
CREATE TYPE Strings AS TABLE ( String1 VARCHAR(50), String2 VARCHAR(50) )
Alter your procedure to accept table type as input
ALTER PROCEDURE Usp_procname (#strings STRINGS Readonly)
AS
..
To call the procedure
DECLARE #strings STRINGS
INSERT INTO #strings
(String1,String2)
SELECT 'String1','String2'
UNION ALL
SELECT 'String3','String4'
UNION ALL
SELECT 'String5','String6'
EXEC Usp_procname #strings
By this way you can pass more than one string in a single call. Make sure you update the logic inside the procedure to handle more than one string
In a case like this one, I usually concatenate strings and split them on the server side or pass even an xml if I have multiple columns. Sql it's very fast when processing xml. You can try all the methods and check the processing time and after that choose the best method.
I am using below query
SELECT #local_variable=Adtid from table where Adtid can have multiple values stored into it. As I don't know what to use instead of '=' in #local_variable=Adtid. Can anyone suggest please what I should use instead of '=' so that my local varaible can have all values of Adtid
The variable can't actually hold multiple values. You can declare a table variable instead, where you can then do something like
declare #tableVariable table
(
Adtid int
);
insert into #tableVariable
select Adtid from table where Adtid ...
This puts the relevant rows inside your table variable. Now you can use the table variable to eg. create a cursor (to go row by row in the data - you can also do that on the original select if you only need to go through once) or use it in a join clause.
You can use below syntax for get the Adtid as comma separator in result
DECLARE #local_variable VARCHAR(100) =''
SELECT #local_variable += CAST(Adtid AS VARCHAR) + ',' FROM TABLE
PRINT #local_variable
and another way as per below answer.
I am using SQL Server 2008, and I am struggling with learning how to correctly call a User-defined In-line Table-Valued Function on a User-defined In-line Table-Valued Function (that is, since each expects a scalar or scalars as input and outputs a table, I want to learn how to correctly call one by passing it another table, whereupon each row is treated as its scalar inputs).
I posted a couple questions related to this recently, but I think I was not clear enough, and did not sufficiently encapsulate the problem to cleanly demonstrate it. I have now prepared the proper statements to provide anyone interested in helping the necessary tables, views, functions, and SELECT outputs to see the problem occur in front of them by executing the query below.
There are several ways I can phrase the core question, and from here and other forums, I can tell I have difficulty clearly expressing it. I am going to phrase it several ways here, but these are all meant to be the same question, phrased differently so people from different backgrounds can more easily understand me.
How do I correctly write the "imageFileNameFromAddress" function below so it works as intended; to wit, the intent is that it takes the same input as "bookAndPageFromAddress" and, using bookAndPageFromAddress and imageFileNameFromBookPage, passing the input to the first, then its output to the second, and returns the second's output?
Why does the third SELECT statement at the bottom below provide different results from the second one, and how do I fix the underlying function(s) to provide identical results, without repeating code from the other functions?
What is the correct syntax for the OUTER APPLY call in imageFileNameFromAddress so that its output is not null?
WARNING: The code below constructs the necessary tables, views, and functions to demonstrate the problem by dropping them first if they exist, so please please please check first to make sure you don't drop anything of your own! The final three SELECTS demonstrate the problem; the final two SELECTS should have identical output, but do not - the first one (of the final two, so the middle of the three) is a three row table of strings, and the final one is a one row table containing only a NULL.
USE [TOM_GIS]
GO
IF OBJECT_ID(N'[dbo].[constant]', N'U') IS NOT NULL
DROP TABLE [dbo].[constant]
CREATE TABLE [dbo].[constant]
(
ID INT IDENTITY(1,1) PRIMARY KEY CLUSTERED,
BOOK varchar(5),
PAGE varchar(5),
DocID numeric(8, 0)
)
INSERT INTO [dbo].[constant]
VALUES(' 4043',' 125', 576030)
GO
IF OBJECT_ID(N'[dbo].[images]', N'U') IS NOT NULL
DROP TABLE [dbo].[images]
CREATE TABLE [dbo].[images]
(
ID INT IDENTITY(1,1) PRIMARY KEY CLUSTERED,
DocID numeric(8, 0),
ImageID numeric(12,0)
)
INSERT INTO [dbo].[images] VALUES(576030, 1589666);
INSERT INTO [dbo].[images] VALUES(576030, 1589667);
INSERT INTO [dbo].[images] VALUES(576030, 1589668);
GO
IF OBJECT_ID(N'[dbo].[addressBookPage]', N'U') IS NOT NULL
DROP TABLE [dbo].[addressBookPage]
CREATE TABLE [dbo].[addressBookPage]
(
ID INT IDENTITY(1,1) PRIMARY KEY CLUSTERED,
PARCEL_ADDRESS nvarchar(50),
BOOK nchar(10),
PAGE nchar(10),
)
INSERT INTO [dbo].[addressBookPage]
VALUES('155 CENTER STREET','4043', '125')
GO
IF OBJECT_ID(N'[dbo].[vw_quindraco]') IS NOT NULL
DROP VIEW [dbo].[vw_quindraco]
GO
CREATE VIEW [dbo].[vw_quindraco]
AS
WITH files AS (SELECT RIGHT('00000000' + LTRIM(STR(c.DocID)), 8) AS PathInfo
,RIGHT('0000000000' + LTRIM(STR(i.ImageID)), 12) AS FileName
,ltrim(c.Book) as Book
,ltrim(c.Page) as Page
FROM [dbo].[constant] AS c INNER JOIN
[dbo].[images] AS i ON c.DocID = i.DocID)
SELECT 'Images/' + SUBSTRING(PathInfo, 1, 2) + '/' + SUBSTRING(PathInfo, 3, 2) + '/' + SUBSTRING(PathInfo, 5, 2)
+ '/' + RIGHT(PathInfo, 8) + '/' + FileName + '.tif' AS FullFileName
,Book
,Page
FROM files AS files_1
GO
IF OBJECT_ID(N'[dbo].[bookAndPageFromAddress]') IS NOT NULL
DROP FUNCTION [dbo].[bookAndPageFromAddress];
GO
CREATE FUNCTION [dbo].[bookAndPageFromAddress] (#address NVARCHAR(max))
RETURNS TABLE AS RETURN(
SELECT PARCEL_ADDRESS AS Address, Book, Page
FROM [dbo].[addressBookPage]
WHERE PARCEL_ADDRESS like '%' + #address + '%'
);
GO
IF OBJECT_ID(N'[dbo].[imageFileNameFromBookPage]') IS NOT NULL
DROP FUNCTION [dbo].[imageFileNameFromBookPage];
GO
CREATE FUNCTION [dbo].[imageFileNameFromBookPage] (#book nvarchar(max), #page nvarchar(max))
RETURNS TABLE AS RETURN(
SELECT i.FullFileName
FROM [dbo].[vw_quindraco] i
WHERE i.Book like #book
AND i.Page like #page
);
GO
IF OBJECT_ID(N'[dbo].[imageFileNameFromAddress]') IS NOT NULL
DROP FUNCTION [dbo].[imageFileNameFromAddress];
GO
CREATE FUNCTION [dbo].[imageFileNameFromAddress] (#address NVARCHAR(max))
RETURNS TABLE AS RETURN(
SELECT *
FROM [dbo].[bookAndPageFromAddress](#address) addresses
OUTER APPLY [dbo].[imageFileNameFromBookPage](addresses.Book, addresses.Page) foo
);
GO
SELECT Book,Page FROM [dbo].[bookAndPageFromAddress]('155 Center Street');
SELECT FullFileName FROM [dbo].[imageFileNameFromBookPage]('4043','125');
SELECT FullFileName FROM [dbo].[imageFileNameFromAddress]('155 Center Street')
You have your table fields as nchars, and you are using Like.
Because it's nchar, the value is padded with spaces to the declared length (10).
Because it's Like, the spaces are considered essential part of a match, whereas the equality operator, =, would ignore trailing spaces.
Because data types in the table and in the function parameters do not match, implicit conversions happen in the background, ultimately causing comparison to fail because of spaces.
Use = instead of Like inside imageFileNameFromBookPage to quickly fix it.
Better yet, use correct data types in all functions and views to avoid any conversions.