Scenario
I have a stored procedure written in T-Sql using SQL Server 2005.
"SEL_ValuesByAssetName"
It accepts a unique string "AssetName".
It returns a table of values.
Question
Instead of calling the stored procedure multiple times and having to make a database call everytime I do this, I want to create another stored procedure that accepts a list of all the "AssetNames", and calls the stored procedure "SEL_ValueByAssetName" for each assetname in the list, and then returns the ENTIRE TABLE OF VALUES.
Pseudo Code
foreach(value in #AllAssetsList)
{
#AssetName = value
SEL_ValueByAssetName(#AssetName)
UPDATE #TempTable
}
How would I go about doing this?
It will look quite crippled with using Stored Procedures. But can you use Table-Valued Functions instead?
In case of Table-Valued functions it would look something like:
SELECT al.Value AS AssetName, av.* FROM #AllAssetsList AS al
CROSS APPLY SEL_ValuesByAssetName(al.Value) AS av
Sample implementation:
First of all, we need to create a Table-Valued Parameter type:
CREATE TYPE [dbo].[tvpStringTable] AS TABLE(Value varchar(max) NOT NULL)
Then, we need a function to get a value of a specific asset:
CREATE FUNCTION [dbo].[tvfGetAssetValue]
(
#assetName varchar(max)
)
RETURNS TABLE
AS
RETURN
(
-- Add the SELECT statement with parameter references here
SELECT 0 AS AssetValue
UNION
SELECT 5 AS AssetValue
UNION
SELECT 7 AS AssetValue
)
Next, a function to return a list AssetName, AssetValue for assets list:
CREATE FUNCTION [dbo].[tvfGetAllAssets]
(
#assetsList tvpStringTable READONLY
)
RETURNS TABLE
AS
RETURN
(
-- Add the SELECT statement with parameter references here
SELECT al.Value AS AssetName, av.AssetValue FROM #assetsList al
CROSS APPLY tvfGetAssetValue(al.Value) AS av
)
Finally, we can test it:
DECLARE #names tvpStringTable
INSERT INTO #names VALUES ('name1'), ('name2'), ('name3')
SELECT * FROM [Test].[dbo].[tvfGetAllAssets] (#names)
In MSSQL 2000 I would make #allAssetsList a Varchar comma separated values list. (and keep in mind that maximum length is 8000)
I would create a temporary table in the memory, parse this string and insert into that table, then do a simple query with the condition where assetName in (select assetName from #tempTable)
I wrote about MSSQL 2000 because I am not sure whether MSSQL 2005 has some new data type like an array that can be passed as a literal to the SP.
Related
I am working on a sql database which will provide with data some grid. The grid will enable filtering, sorting and paging but also there is a strict requirement that users can enter free text to a text input above the grid for example
'Engine 1001 Requi' and that the result will contain only rows which in some columns contain all the pieces of the text. So one column may contain Engine, other column may contain 1001 and some other will contain Requi.
I created a technical column (let's call it myTechnicalColumn) in the table (let's call it myTable) which will be updated each time someone inserts or updates a row and it will contain all the values of all the columns combined and separated with space.
Now to use it with entity framework I decided to use a table valued function which accepts one parameter #searchQuery and it will handle it like this:
CREATE FUNCTION myFunctionName(#searchText NVARCHAR(MAX))
RETURNS #Result TABLE
( ... here come columns )
AS
BEGIN
DECLARE #searchToken TokenType
INSERT INTO #searchToken(token) SELECT value FROM STRING_SPLIT(#searchText,' ')
DECLARE #searchTextLength INT
SET #searchTextLength = (SELECT COUNT(*) FROM #searchToken)
INSERT INTO #Result
SELECT
... here come columns
FROM myTable
WHERE (SELECT COUNT(*) FROM #searchToken WHERE CHARINDEX(token, myTechnicalColumn) > 0) = #searchTextLength
RETURN;
END
Of course the solution works fine but it's kinda slow. Any hints how to improve its efficiency?
You can use an inline Table Valued Function, which should be quite a lot faster.
This would be a direct translation of your current code
CREATE FUNCTION myFunctionName(#searchText NVARCHAR(MAX))
RETURNS TABLE
AS RETURN
(
WITH searchText AS (
SELECT value token
FROM STRING_SPLIT(#searchText,' ') s(token)
)
SELECT
... here come columns
FROM myTable t
WHERE (
SELECT COUNT(*)
FROM searchText
WHERE CHARINDEX(s.token, t.myTechnicalColumn) > 0
) = (SELECT COUNT(*) FROM searchText)
);
GO
You are using a form of query called Relational Division Without Remainder and there are other ways to cut this cake:
CREATE FUNCTION myFunctionName(#searchText NVARCHAR(MAX))
RETURNS TABLE
AS RETURN
(
WITH searchText AS (
SELECT value token
FROM STRING_SPLIT(#searchText,' ') s(token)
)
SELECT
... here come columns
FROM myTable t
WHERE NOT EXISTS (
SELECT 1
FROM searchText
WHERE CHARINDEX(s.token, t.myTechnicalColumn) = 0
)
);
GO
This may be faster or slower depending on a number of factors, you need to test.
Since there is no data to test, i am not sure if the following will solve your issue:
-- Replace the last INSERT portion
INSERT INTO #Result
SELECT
... here come columns
FROM myTable T
JOIN #searchToken S ON CHARINDEX(S.token, T.myTechnicalColumn) > 0
I use SQL server 2016.
I want to write a function that takes a table as a parameter and then performs a join on that table with another table.
I have declared the following type:
CREATE TYPE WorklistTable AS TABLE (WorklistId int NOT NULL)
Then I use it in a lot of functions that do selects based on certain conditions
CREATE FUNCTION [dbo].[fnGetSomeData] (
#WorklistIds WorklistTable readonly
)
RETURNS TABLE
AS RETURN
(
select WorklistId, wlu.UserId
from #WorklistIds
join [dbo].[WorklistUser] wlu on wlu.WorklistId = #WorklistIds.worklistId
-- the rest is omitted
);
I get the following error:
Must declare the scalar variable "#WorklistIds".
I tried to declare the variable, but I got an error:
The variable name '#WorklistIds' has already been declared. Variable names must be unique within a query batch or stored procedure.
You should use aliases when you are joing to table variable.
CREATE FUNCTION [dbo].[fnGetSomeData] (
#WorklistIds WorklistTable readonly
)
RETURNS TABLE
AS RETURN
(
select WorklistId, wlu.UserId
from #WorklistIds t
join [dbo].[WorklistUser] wlu on wlu.WorklistId = t.worklistId
-- the rest is omitted
);
You can't directly use the #Table name when referencing a column within a table variable. You either need to alias the table or wrap it in square brackets:
select WorklistId, wlu.UserId
from #WorklistIds As W
join [dbo].[WorklistUser] wlu on wlu.WorklistId = W.worklistId
Or
select WorklistId, wlu.UserId
from #WorklistIds
join [dbo].[WorklistUser] wlu on wlu.WorklistId = [#WorklistIds].worklistId
There is function Getfunctionname(userid, startdate, enddate) to return a table
My question is can I pass a variable with multiple values?
i.e.
getfunctionname(#userid, startdate, enddate)
Where the value of variable #userid is like
1
2
3
4
5
(actually using split function splitting the values from being 1,2,3,4,5 )
If I can please let me know
One way of doing that which I prefer is to make a new user-defined table data type.
CREATE TYPE [dbo].[IdList] AS TABLE(
[Id] [int] NULL
)
Then you can use that data type as one of the parameters
CREATE FUNCTION Getfunctionname
(
#UserIDs dbo.IdList READONLY,
#startdate INT,
#endtdate INT
)
RETURNS #ReturnTable TABLE
(
-- ReturnTable
)
AS
BEGIN
-- Query
RETURN
END
Use the concept of CSV
CREATE FUNCTION [dbo].[uspGetNumbers]
userid,startdate,enddate // define your paramters the way you want
AS
BEGIN
// your code
JOIN dbo.fnSplit(#UserIDs, ',')
END
GO
Example function:
SELECT [dbo].[uspGetNumbers] '1,2,3,4,5', '', ''
I just ran into this, and I used the CROSS APPLY solution from this post:
SQL Server: run function for each row based on the provided row value
To use CROSS APPLY, you would need to first select your values, and then CROSS APPLY. I have not used the split function before, so I don't have the exact syntax,
but if you use it something like:
select #userid, F1.* from split(1,2,3,4,5),
CROSS APPLY getfunctionname(#userid, startdate, enddate) F1
Is there a way to input multiple values in a single parameter of a scalar-valued function in SQL Server 2008 R2 and have it filter data by that parameter using both values?
For example I would like to do the following
SET #Salesperson='BILL' OR 'MOSES'
SELECT Sum(SalesDollars)
FROM Invoices
WHERE Invoices.Salesperson = #Salesperson
I attempted to use the following as the WHERE clause, but this didnt work either.
SET #Salesperson='BILL','MOSES'
SELECT Sum(SalesDollars)
FROM Invoices
WHERE Invoices.Salesperson IN (#Salesperson)
Would it be easier if i were dealing with integers as opposed to varchar values?
Any help would be absolutely appreciated!
You need to use table-valued parameters. Look it up on technet or msdn
Best part of it that your table-valued parameters can have multiple columns.
Note however that you have to define TVP parameter as readonly. So if you want to return similar set from your function you will need to create another variable inside your function.
Example:
CREATE TYPE Names AS TABLE
( Name VARCHAR(50));
GO
/* Create a procedure to receive data for the table-valued parameter. */
CREATE PROCEDURE dbo.mySP
#n Names READONLY
AS
SELECT Sum(SalesDollars)
FROM
WHERE Invoices.Salesperson in (select Name from #n)
GO
CREATE FUNCTION dbo.myFun(#n Names READONLY) returns int
AS
SELECT Sum(SalesDollars)
FROM
WHERE Invoices.Salesperson in (select Name from #n)
GO
/* Declare a variable that references the type. */
DECLARE #names AS Names;
/* Add data to the table variable. */
INSERT INTO #names (Name)
VALUES ('BILL'),('MOSES')
-- using stored procedure with TVP
EXEC dbo.mySP #names
-- using function with TVP
select dbo.myFun(#names)
GO
This could be done this way:
SET #Salesperson='BILL,MOSES'
SELECT *
FROM YourTable
WHERE Invoices.Salesperson IN (SELECT * FROM dbo.split(#Salesperson,','))
This is how you split the values.
I would typically do this using a user defined table type: SQL Fiddle Example.
CREATE TYPE <schema>.SalespersonList AS TABLE
(
Name varchar(32)
)
You may have to grant execute permissions on the type:
GRANT EXECUTE ON TYPE::<schema>.SalespersonList TO <user>
Then you can create a function to use it:
CREATE FUNCTION <schema>.fnGetTotalSales
(
#nameList <schema>.SalespersonList READONLY
)
RETURNS INT
AS
BEGIN
DECLARE #ret INT
SELECT #ret = Sum(SalesDollars)
FROM Invoices i
INNER JOIN #nameList nl ON nl.Name = i.Salesperson
RETURN #ret
END
Then you would just insert your list into the type and call the function:
DECLARE #salesPersonList <schema>.SalespersonList
INSERT INTO #salesPersonList (Name)
SELECT 'Bill'
UNION
SELECT 'Moses'
SELECT <schema>.fnGetTotalSales(#salesPersonList)
Suppose I want to get student summaries from a two tables: student, grade:
CREATE PROCEDURE prc_get_student_grade_summaries
#studentIds [Integer_udtt] READONLY
AS
BEGIN
SELECT Name,
func_GetGradeAForStudent()
FROM tbl_student AS tS
INNER JOIN
#studentIds AS tSI
ON tS.Id = tSI.studentId
Integer udtt is defined as this:
CREATE TYPE [Integer_udtt] AS TABLE (
[Id] INT NOT NULL,
PRIMARY KEY CLUSTERED ([Id] ASC));
func_GetGradeAForStudent is something like select COUNT(*) from student where studentId = id AND grade = 1 -- 1: A
The result I want is list of summary:
StudentId Number of A
101 5
102 4
103 2
What is the correct way to pass in the studentId from #studentIds to the func_GetGradeAForStudent?
You can't pass table-value parameters to UDF's:
MSDN:
Limitations of Table-Valued Parameters
There are several limitations to table-valued parameters:
You cannot pass table-valued parameters to user-defined functions.
Table-valued parameters can only be indexed to support UNIQUE or PRIMARY KEY constraints. SQL Server does not maintain statistics on
table-valued parameters.
Table-valued parameters are read-only in Transact-SQL code. You cannot update the column values in the rows of a table-valued
parameter and you cannot insert or delete rows. To modify the data
that is passed to a stored procedure or parameterized statement in
table-valued parameter, you must insert the data into a temporary
table or into a table variable.
You cannot use ALTER TABLE statements to modify the design of table-valued parameters.
Since these are just a list of student Ids, one possibility would be to pass those Ids as a comma-separeted list of ids and use a split function to recreate a table from the comma-separeted list. There's a ton of examples here on SO and elsewhere where you can find sample implementation of a split function.
Or even better, do everything inside your proc. I don't really see the need for that function if all is doing is a select count(*)... You should be able to do everything inline, perhaps using a subselect as so:
CREATE PROCEDURE prc_get_student_grade_summaries
#studentIds [Integer_udtt] READONLY
AS
BEGIN
SELECT Name,
(select COUNT(*) from student where studentId = tSI.studentId AND grade = 1 ) as NumberOfAs
FROM tbl_student AS tS
INNER JOIN
#studentIds AS tSI
ON tS.Id = tSI.studentId
UPDATE
Sample split function that takes a comma-separated list and returns a table:
CREATE FUNCTION [dbo].[fnSplit](
#sInputList VARCHAR(8000) -- List of delimited items
, #sDelimiter VARCHAR(8000) = ',' -- delimiter that separates items
) RETURNS #List TABLE (item VARCHAR(8000))
BEGIN
DECLARE #sItem VARCHAR(8000)
WHILE CHARINDEX(#sDelimiter,#sInputList,0) <> 0
BEGIN
SELECT
#sItem=RTRIM(LTRIM(SUBSTRING(#sInputList,1,CHARINDEX(#sDelimiter,#sInputList,0)-1))),
#sInputList=RTRIM(LTRIM(SUBSTRING(#sInputList,CHARINDEX(#sDelimiter,#sInputList,0)+LEN(#sDelimiter),LEN(#sInputList))))
IF LEN(#sItem) > 0
INSERT INTO #List SELECT #sItem
END
IF LEN(#sInputList) > 0
INSERT INTO #List SELECT #sInputList -- Put the last item in
RETURN
END
And you call it like this: select * from fnSplit(#CommaSeparetedList,',');