I have a large dataset that is being returned from a view in SQL Server 2012. I need to filter the data based on 6 different criteria. I have set up parameters in the report and want to use the parameters in the query to reduce the size.
So I have the following situation:
select * from vw_ABC where p1 in #p1 and p2 in #p2 ...
The tricky part is how to handle a situation where the user does not want to filter on one of the criteria. I am trying to avoid dynamic sql but if that is the only way so be it.
When the report is called the user will have all 6 parameters listed. The default values will be 'ALL'. They can create the report with one or all of the parameters. Most cases it will be 2 or 3 (name city zip orderid things like this)
Any help would be greatly appreciated.
I suppose you are not talking about IN but rather about =. That would be:
select *
from vw_ABC
where (p1 = #p1 or #p1 = 'ALL')
and (p2 = #p2 or #p2 = 'ALL')
...
Set up the parameters as optional and check NULLs....let me dig up an example for you
declare #id int = 1
select * from users u
where (#id IS NULL and u.id=u.id) or (u.id=#id)
One approach is to create a second set of parameters to indicate whether or not the corresponding parameter needs to be used:
SELECT *
FROM vw_ABC
WHERE
(#u1=0 OR p1=#p1)
AND (#u2=0 OR p2=#p2)
AND (#u3=0 OR p3=#p3)
This way you do not need to reserve a special value to mean all: if you want to use #pX, set #uX to 1, where X is parameter number.
Related
I have a Stored Procedure to get the details of Invoices
Some occasions I get the list of invoices by sending only the InvoiceID
But in some other occasions I need to get the list of invoices as per the search fields supplied by the user. To do this I send all the fields to the Stored Procedure and use those parameters as below. I included only 2 columns but there are more.
SELECT * FROM INVOICES I
WHERE
(#InvoiceNumber is null or I.InvoiceNumber = #InvoiceNumber)
and
(#PONo is null or I.PONo = #PONo)
Is there a way to send the condition for the WHERE clause as one parameter?
Yes, it is possible with Dynamic SQL, but I highly discourage to do that.
SELECT * FROM tbl WHERE #condition:
If you are considering to write the procedure
CREATE PROCEDURE search_sp #condition varchar(8000) AS
SELECT * FROM tbl WHERE #condition
Just forget it. If you are doing this, you have not completed the transition to use stored procedure and you are still assembling your
SQL code in the client.
It will also open your application to SQL Injection attacks.
You can use custom type to pass table as parameter https://msdn.microsoft.com/pl-pl/library/bb510489(v=sql.110).aspx or you can use default parameters
If you're using SQL Server 2016 or similar (check by calling select compatibility_level, name from sys.databases and seeing that your DB is 130 or higher) then you can use the string_split builtin function.
I found it works best like this (spread out for clarity)
CREATE PROCEDURE [dbo].[GetInvoices]
#InvoiceNumber int = NULL
#PONo nvarchar(1024) = NULL
AS
SELECT * from [Invoices] AS [i]
WHERE
i.InvoiceNumber = ISNULL(#InvoiceNunber, i.InvoiceNunber)
AND CASE
WHEN #PONo is null
THEN 1
ELSE (CASE
WHEN i.PONo IN (select value from string_split(#PONo, ','))
THEN 1
ELSE 0
END)
END
= 1
So if you pass in a null to either parameter it gets translated as where x = x which is always true, and if you pass in a CSV value, it selects it from a split table of values that, if present, results in the where clause being where 1=1, which is true or 0=1 if the value is not present in the input list.
So here you can pass in an invoice number, or PO number, or both, or neither and it should return what you expect.
I have a Table Tab1. I want to make a stored procedure, in which I will take up to 3 parameters from the user and select data from the table using the AND operator. Like:
Select * from Tab1
Where Para1=1 AND Para2=1 AND Para3=4
But I have a condition that the user can pass one, or two, or all three parameters. I want to write a single query such that if he passes all three parameters, then select data according these 3 parameters using the AND operator; if he passes any two parameters, select data according to those two parameters using the AND operator. Lastly, he may pass a single parameter, so then select data according this single parameter.
Is any way to write a single query for above requirement?
SELECT *
FROM Tab1
WHERE (#Para1 IS NULL OR (Para1 = #Para1))
AND (#Para2 IS NULL OR (Para2 = #Para2))
AND (#Para3 IS NULL OR (Para3 = #Para3))
OPTION (RECOMPILE);
So how is this possible, its because in OR short-circuits, i.e. when #Para1 is null (assuming default is null when there is no value) it doesn't go to second condition i.e. Para1 = #Para1, might be due to performance reason coz first is already satisfied which is what OR actually means i.e. to check if any clause is satisfied and similarly with rest of logic Or you can do dynamic query too
Adding to comment below by KM.
It better using OPTION (RECOMPILE), then the execution plan won't be reused coz the select depends hugely on parameters here which are dynamic so adding OPTION (RECOMPILE) would re-generate execution plan.
Try something like:
CREATE PROCEDURE usp_Test
#param1 int = NULL
, #param2 int = NULL
, #param3 int = NULL
AS
BEGIN
SELECT * FROM Tab1
WHERE (Para1 = #param1 OR #param1 IS NULL)
AND (Para2 = #param2 OR #param2 IS NULL)
AND (Para3 = #param3 OR #param3 IS NULL)
END
I have a statement like this below in one of my big stored proc, and I am wondering if this is valid to write this way.
SELECT #PVDate = pv.Date,
#PVdMBeginDate = dbo.fPVoidDate(pv.myID)
FROM PVMeter pv (NOLOCK)
WHERE pv.PR_ID = #PR_ID
AND #VCommen BETWEEN pv.PVDMDate AND dbo.fPVoidDate(pv.myID)
Now, here, my question is, #VCommen is a declared date variable with a value set on it. It is not at all a column of PVMeter, while PVDMDate is a column in PVMeter and fpVoidDate returns datetime
While I debug SP, I do not see the value on #PVDate and #PVDMBeginDate
The original query is equivalent to:
SELECT
#PVDate = pv.Date,
#PVdMBeginDate = dbo.fPVoidDate(pv.myID)
FROM PVMeter pv (NOLOCK)
WHERE
pv.PR_ID = #PR_ID
AND pv.PVDMDate <= #VCommen
AND #VCommen <= dbo.fPVoidDate(pv.myID)
This style should be more familiar. In general, you can put any expression in the WHERE clause, it can be made of variables or constants without referring to table columns at all.
Examples
Classic example: WHERE 1=1 ... when the query text is generated dynamically. It is easy to add as many expressions as needed in no particular order and prepend all of them with AND.
DECLARE #VarSQL nvarchar(max);
SET #VarSQL = 'SELECT ... FROM ... WHERE 1=1 ';
IF ... THEN SET #VarSQL = #VarSQL + ' AND expression1';
IF ... THEN SET #VarSQL = #VarSQL + ' AND expression2';
IF ... THEN SET #VarSQL = #VarSQL + ' AND expression3';
EXEC #VarSQL;
Thus you don't need to have complex logic determining whether you need to add an AND before each expression or not.
Another example.
You have a stored procedure with parameter #ParamID int.
You have a complex query in the procedure that usually returns many rows and one column of the result set is some unique ID.
SELECT ID, ...
FROM ...
WHERE
expression1
AND expression2
AND expression3
...
You want to return all rows if #ParamID is NULL and only one row with the given ID if #ParamID is not NULL. I personally use this approach. When I open the screen with the results of a query for the first time I want to show all rows to the user, so I pass NULL as a parameter. Then user makes changes to a selected row, which is done through a separate UPDATE statement. Then I want to refresh results that user sees on the screen. I know ID of the row that was just changed, so I need to requery just this row, so I pass this ID to procedure and fetch only one row instead of the whole table again.
The final query would look like this:
SELECT ID, ...
FROM ...
WHERE
(#ParamID IS NULL OR ID = #ParamID)
AND expression1
AND expression2
AND expression3
...
OPTION (RECOMPILE);
Thus I don't have to repeat the complex code of the query twice.
I have a stored procedure with default values, which I set to NULL. In the WHERE clause, for each value specified, rather than NULL or not given (where it would also be NULL), I would like the column to equal this value, otherwise, I would like to search without this column being in the WHERE clause. The basic structure looks something like this:
// Set up the stored procedure
USE Table;
GO
CREATE PROCEDURE dbo.SearchTable
// Specify value(s)
#Name varchar(50) = NULL
AS
// Set up the query
IF(#Name IS NOT NULL
SELECT * FROM Table WHERE Name=#Name;
ELSE
SELECT * FROM Table
BEGIN
END
I have more than 1 parameter, and so, with this logic, I would need 2 IF's for every parameter. As you can imagine, this gets boring, time-consuming, and error-prone fast.
I would like to move this logic into the query, preferably into the WHERE clause, but any way I have found will cause errors (besides exceptions, which would require just as many IF's). SQL Server doesn't like IF's in the WHERE clause as far as I know, and with CASE I would have to specify the column, which I do not want to do.
What should I do?
Edit:
I have SQL Server version 2012, so please concentrate on this or any recent versions in your answer.
If you don't care about performance, you can do:
SELECT *
FROM Table
WHERE #Name is null or Name = #Name;
Often, having an or condition gets in the way of efficient use of indexes. Perhaps this isn't a problem in your case, though.
You could do something like this. The downside to this is that indexes may not be used properly and thus the performance may not be great.
SELECT * FROM Table
WHERE (#Name Is Null Or Name = #Name)
And (#Col2 Is Null Or Col2 = #Col2)
And (#Col3 Is Null Or Col3 = #Col3)
Each column condition is "anded". Or is used to apply that column condition only if #var is not null. So for example, if this is called with just #Name populated, it is equivalent to Where Name = #Name. If both #Name and #Col2 are populated, it is equivalent to Where Name = #Name And Col2 = #Col2.
I want to build a single select stored procedure for SQL 2005 that is universal for any select query on that table.
**Columns**
LocationServiceID
LocationID
LocationServiceTypeID
ServiceName
ServiceCode
FlagActive
For this table I may need to select by LocationServiceID, or LocationID, or LocationServiceTypeID or ServiceName or a combination of the above.
I'd rather not have a separate stored procedure for each of them.
I assume the best way to do it would be to build the 'WHERE' statement on NOT NULL. Something like
SELECT * FROM LocationServiceType WHERE
IF #LocationID IS NOT NULL (LocationID = #LocationID)
IF #LocationServiceID IS NOT NULL (LocationServiceID = #LocationServiceID)
IF #LocationServiceTypeID IS NOT NULL (LocationServiceTypeID = #LocationServiceTypeID)
IF #ServiceName IS NOT NULL (ServiceName = #ServiceName)
IF #ServiceCode IS NOT NULL (ServiceCode = #ServiceCode)
IF #FlagActive IS NOT NULL (FlagActive = #FlagActive)
Does that make sense?
here is the most extensive article I've ever seen on the subject:
Dynamic Search Conditions in T-SQL by Erland Sommarskog
here is an outline of the article:
Introduction
The Case Study: Searching Orders
The Northgale Database
Dynamic SQL
Introduction
Using sp_executesql
Using the CLR
Using EXEC()
When Caching Is Not Really What You Want
Static SQL
Introduction
x = #x OR #x IS NULL
Using IF statements
Umachandar's Bag of Tricks
Using Temp Tables
x = #x AND #x IS NOT NULL
Handling Complex Conditions
Hybrid Solutions – Using both Static and Dynamic SQL
Using Views
Using Inline Table Functions
Conclusion
Feedback and Acknowledgements
Revision History
First of all, your code will not work. It should look like this:
SELECT * FROM LocationServiceType WHERE
(#LocationID IS NULL OR (LocationID = #LocationID)
... -- all other fields here
This is totally valid and known as 'all-in-one query'. But from a performance point of view this is not a perfect solution as soon as you don't allow SQL Server to select optimal plan. You can see more details here.
Bottom line: if your top priority is 'single SP', then use this approach. In case you care about the performance, look for a different solution.
SELECT *
FROM LocationServiceType
WHERE LocationServiceID = ISNULL(#LocationServiceID,LocationServiceID)
AND LocationID = ISNULL(#LocationID,LocationID)
AND LocationServiceTypeID = ISNULL(#LocationServiceTypeID,LocationServiceTypeID)
AND ServiceName = ISNULL(#ServiceName,ServiceName)
AND ServiceCode = ISNULL(#ServiceCode,ServiceCode)
AND FlagActive = ISNULL(#FlagActive,FlagActive)
If a null value is sent in it will cancel out that line of the where clause, otherwise it will return rows that match the value sent in.
What I've always done is is set the incoming parameters to null if should be ignored in query
then check variable for null first, so if variable is null condition short circuits and filter is not applied. If variable has value then 'or' causes filter to be used. Has worked for me so far.
SET #LocationID = NULLIF(#LocationID, 0)
SET #LocationServiceID = NULLIF(#LocationServiceID, 0)
SET #LocationServiceTypeID = NULLIF(#LocationServiceTypeID, 0)
SELECT * FROM LocationServiceType WHERE
(#LocationID IS NULL OR LocationID = #LocationID)
AND (#LocationServiceID IS NULL OR LocationServiceID = #LocationServiceID)
AND (#LocationServiceTypeID IS NULL OR #LocationServiceTypeID = #LocationServiceTypeID)
etc...