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
Related
I have a stored procedure that accepts an optional #ID param. When the param is passed in, I want the WHERE statement to include something like id = #ID, otherwise, when #ID is null, I don't want it to be filtered.
For example:
#ID BIGINT = NULL
SELECT * from myTable
WHERE
CASE
WHEN #ID IS NOT NULL THEN mytable.id = #ID
END
I am running this in SQL server 2016 and it says bad syntax near mytable.id = #ID. Can CASE be used in this way or should I try a different SQL method for this?
The only other option I considered to accomplish this was by using IF conditions in my stored procedure, but that didn't seem possible either based on my searches.
CASE is an expression, not a statement. It is not used to control flow like this and it will not work.
Your logic would need to be something like this.
Where mytable.id = ISNULL(#ID, mytable.id)
I should caution you that this pattern can lead to some poor performance. For a more detailed explanation and some other options you should check out this article. http://www.sqlinthewild.co.za/index.php/2009/03/19/catch-all-queries/
A bad-performance approach would be:
WHERE ISNULL(#ID,mytable.id) = mytable.id
A better-performance approach would be:
if(#ID IS NULL)
select * from ... without the WHERE condition
else
do your query with the condition mytable.id = #ID
Or build the query dynamically in the stored proc and execute it through sp_executesql passing parameters
Note: If the table is small enough, stick to simplicity and use the first option.
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 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.
Everyone has been a super help so far. My next question is what is the best way for me to approach this... If I have 7 fields that a user can search what is the best way to conduct this search, They can have any combination of the 7 fields so that is 7! or 5040 Combinations which is impossible to code that many. So how do I account for when the User selects field 1 and field 3 or they select field 1, field 2, and field 7? Is there any easy to do this with SQL? I dont know if I should approach this using an IF statement or go towards a CASE in the select statement. Or should I go a complete different direction? Well if anyone has any helpful pointers I would greatly appreciate it.
Thank You
You'll probably want to look into using dynamic SQL for this. See: Dynamic Search Conditions in T-SQL and Catch-all queries for good articles on this topic.
Select f1,f2 from table where f1 like '%val%' or f2 like '%val%'
You could write a stored procedure that accepts each parameter as null and then write your WHERE clause like:
WHERE (field1 = #param1 or #param1 is null)
AND (field2 = #param2 or #param2 is null) etc...
But I wouldn't recommend it. It can definitely affect performance doing it this way depending on the number of parameters you have. I second Joe Stefanelli's answer with looking into dynamic SQL in this case.
Depends on:
how your data looks like,
how big they are,
how exact result is expected (all matching records or top 100 is enough),
how much resources has you database.
you can try something like:
CREATE PROC dbo.Search(
#param1 INT = NULL,
#param2 VARCHAR(3) = NULL
)
AS
BEGIN
SET NOCOUNT ON
-- create temporary table to keep keys (primary) of matching records from searched table
CREATE TABLE #results (k INT)
INSERT INTO
#results(k)
SELECT -- you can use TOP here to norrow results
key
FROM
table
-- you can use WHERE if there are some default conditions
PRINT ##ROWCOUNT
-- if #param1 is set filter #result
IF #param1 IS NOT NULL BEGIN
PRINT '#param1'
;WITH d AS (
SELECT
key
FROM
table
WHERE
param1 <> #param1
)
DELETE FROM
#results
WHERE
k = key
PRINT ##ROWCOUNT
END
-- if #param2 is set filter #result
IF #param2 IS NOT NULL BEGIN
PRINT '#param2'
;WITH d AS (
SELECT
key
FROM
table
WHERE
param2 <> #param2
)
DELETE FROM
#results
WHERE
k = key
PRINT ##ROWCOUNT
END
-- returns what left in #results table
SELECT
table.* -- or better only columns you need
FROM
#results r
JOIN
table
ON
table.key = r.k
END
I use this technique on large database (millions of records, but running on large server) to filter data from some predefined data. And it works pretty well.
However I don't need all matching records -- depends on query 10-3000 matching records is enough.
If you are using a stored procedure you can use this method:
CREATE PROCEDURE dbo.foo
#param1 VARCHAR(32) = NULL,
#param2 INT = NULL
AS
BEGIN
SET NOCOUNT ON
SELECT * FROM MyTable as t
WHERE (#param1 IS NULL OR t.Column1 = #param1)
AND (#param2 IS NULL OR t.COlumn2 = #param2)
END
GO
These are usually called optional parameters. The idea is that if you don't pass one in it gets the default value (null) and that section of your where clause always returns true.
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...