I have the following table:
ThisCategoryID int IDENTITY, AUTO_INCREMENT
Title text
Type text
CategoryID int ALLOW NULLS
IsActive bit
OrderIndex int ALLOW NULLS
with this data:
ThisCategoryID Title Type CategoryID IsActive OrderIndex
0 Lunch Menu Section NULL True 3
2 Dessert Menu Section NULL True 1
3 Banh Mi Food Item 0 True 4
and the following stored procedure:
ALTER PROCEDURE [dbo].[sp_new_category]
#Title text,
#Type text,
#CategoryID int = null,
#IsActive bit,
#OrderIndex int = null
AS
DECLARE #Identity int
IF (SELECT count(*) FROM Category WHERE difference(title, #title) = 4) > 0
BEGIN
INSERT INTO Category (Title, Type, CategoryID, IsActive, OrderIndex) VALUES (#Title, #Type, #CategoryID, #IsActive, #OrderIndex)
SET #Identity = scope_identity()
END
ELSE
BEGIN
SET #Identity = -1
END
SELECT #Identity AS ID
RETURN #Identity
There is no item in the table with the title "Snack", yet the sp_new_category yields -1, every time I run it with the following parameters:
#Title: Snack
#Type: Menu Section
#CategoryID: NULL
#IsActive: True
#OrderIndex: NULL
Can someone explain to me why that is?
I believe your intent for the following conditional is to check if someone is trying enter an already existing item by Title (matched with SOUNDEX):
IF (SELECT count(*) FROM Category WHERE difference(title, #title) = 4) > 0
However, the way the conditional is written, you will only add items if they are similar. Try this instead:
DECLARE #Identity int
IF (SELECT count(*) FROM Category WHERE difference(title, #title) = 4) > 0
BEGIN
SET #Identity = -1
END
ELSE
BEGIN
INSERT INTO Category (Title, Type, CategoryID, IsActive, OrderIndex) VALUES (#Title, #Type, #CategoryID, #IsActive, #OrderIndex)
SET #Identity = scope_identity()
END
SELECT #Identity AS ID
RETURN #Identity
SELECT difference('Snack', 'Lunch')
UNION SELECT difference('Snack', 'Dessert')
UNION SELECT difference('Snack', 'Banh Mi')
3
1
2
None of your differences ever equal 4, so your insert is never run, so #identity will always be -1
difference is the difference in SOUNDEX encodings for text, which is an archaic hash for English names. It is not suitable for foreign words. If you tell us what you think you are accomplishing by using it, we may be able to help you.
Am I missing something?
The IF statement is false so he goes to the ELSE and puts SET #Identity = -1. So it'll return -1.
Related
I have a Songs table with a likes column that holds the number of likes users sent . Each user sends a boolean (1 or 0) through a C# app which adds to the likes column.
About my procedure:
I want to know if there is more an efficient and short way of writing the part 1 of the function?
I had to manually insert '0' instead of the NULL for the first time for the function to work. It wasn't working because the initial value for Likes column is NULL. Is there a way to affect the row for the first time when it has NULL in it?
For part 2 of the function with [Users_Likes_Songs] table, I want to update if the user send a like (true = 1) or removed it (false = 0).
How can I update this table for the first time when the users 'like' must be valued as '1', when its rows are completely empty?
I thank you very much if you can help me.
The procedure:
CREATE PROCEDURE Songs_Likes
#User_ID INT,
#SongID INT,
#Song_like BIT
AS
BEGIN
--- part 1 of the function
IF (#Song_like = 1)
BEGIN
UPDATE [Songs]
SET [Likes] = [Likes] + #Song_like
WHERE [Song_ID] = #SongID
END
IF (#Song_like = 0)
BEGIN
UPDATE [Songs]
SET [Likes] = [Likes] - 1
WHERE [Song_ID] = #SongID
END
--- part 2 of the function with the second table
UPDATE [Users_Likes_Songs]
SET [LikeSong] = #Song_like
WHERE ([UserID] = #User_ID) AND ([SongID] = #SongID)
END
I think that the better method would be to change your design to calculate the likes and have a table that stores the likes for each user. In simple terms, something like:
USE Sandbox;
GO
CREATE SCHEMA music;
GO
CREATE TABLE music.song (SongID int IDENTITY(1,1),
Artist nvarchar(50) NOT NULL,
Title nvarchar(50) NOT NULL,
ReleaseDate date);
CREATE TABLE music.[User] (UserID int IDENTITY(1,1),
[Login] nvarchar(128));
CREATE TABLE music.SongLike (LikeID bigint IDENTITY(1,1),
SongID int,
UserID int,
Liked bit);
CREATE UNIQUE NONCLUSTERED INDEX UserLike ON music.SongLike(SongID, UserID); --Stops multiple likes
GO
--To add a LIKE you can then have a SP like:
CREATE PROC music.AddLike #SongID int, #UserID int, #Liked bit AS
BEGIN
IF EXISTS (SELECT 1 FROM music.SongLike WHERE UserID = #UserID AND SongID = #SongID) BEGIN
UPDATE music.SongLike
SET Liked = #Liked
WHERE UserID = #UserID
AND SongID = #SongID
END ELSE BEGIN
INSERT INTO music.SongLike (SongID,
UserID,
Liked)
VALUES (#SongID, #UserID, #Liked);
END
END
GO
--And, if you want the number of likes:
CREATE VIEW music.SongLikes AS
SELECT S.Artist,
S.Title,
S.ReleaseDate,
COUNT(CASE SL.Liked WHEN 1 THEN 1 END) AS Likes
FROM music.Song S
JOIN music.SongLike SL ON S.SongID = SL.SongID
GROUP BY S.Artist,
S.Title,
S.ReleaseDate;
GO
For 1) this is a bit clearer, shorter and a bit more efficient.
UPDATE [Songs]
SET [Likes] = COALESCE([Likes], 0) + CASE WHEN #Song_like = 1 THEN 1
WHEN #Song_like = 0 THEN -1
ELSE 0 END
WHERE [Song_ID] = #SongID;
For the second part you can do something like this:
IF NOT EXISTS (SELECT 1
FROM [Users_Likes_Songs]
WHERE [UserID] = #User_ID
AND [SongID] = #SongID)
INSERT INTO [Users_Likes_Songs] (User_ID, SongID, [LikeSong])
VALUES (#User_ID, #SongID, #Song_like)
ELSE
UPDATE [Users_Likes_Songs]
SET [LikeSong] = #Song_like WHERE ([UserID] = #User_ID) AND ([SongID] = #SongID)
You can try this query in your procedure
UPDATE [songs]
SET [likes] = Isnull ([likes], 0) + ( CASE WHEN #Song_like THEN 1 ELSE -1 END)
WHERE [song_id] = #SongID
I've been trying to get this right for some time now with no use.
I have a table in mssql database and I want to insert new row using stored procedure
CREATE TABLE "Customers" (
"CustomerID" NCHAR(5) NOT NULL,
"CompanyName" NVARCHAR(40) NOT NULL,
"ContactName" NVARCHAR(30) NULL,
"ContactTitle" NVARCHAR(30) NULL,
"Address" NVARCHAR(60) NULL,
"City" NVARCHAR(15) NULL,
"Region" NVARCHAR(15) NULL,
"PostalCode" NVARCHAR(10) NULL,
"Country" NVARCHAR(15) NULL,
"Phone" NVARCHAR(24) NULL,
"Fax" NVARCHAR(24) NULL,
PRIMARY KEY ("CustomerID")
);
The problem is CustomerID field which contains unique string for each record (ALFKI, BERGS, BERGS, etc.)
I want to make a stored procedure which will insert a row with new data and create an unique CustomerID. Build in functions are out of a question as I need the string to be 5 chars long.
I have a procedure which generates 5 chars ID as follows
begin
declare #chars char(26) = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
declare #i int = 0
declare #id varchar(max) = ''
while #i < 5
begin
set #id = #id + substring(#chars, cast(ceiling(rand() * 26) as int), 1)
set #i = #i + 1
end
Select (cast(#id as nvarchar(400)))
end
And the one that I tried to make work with no use. It is supposed to select an unique id (set #id = 'ANATR' is there on purpose to make it go into the loop
begin
declare #randID varchar(5) = ''
declare #selectID varchar(20) = ''
declare #chars char(26) = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
declare #i int = 0
declare #id varchar(10) = ''
while #i < 5
begin
set #id = #id + substring(#chars, cast(ceiling(rand() * 26) as int), 1)
set #i = #i + 1
end
select #id
set #id = 'ANATR'
SET #selectID = (SELECT CustomerID FROM CUSTOMERS WHERE CustomerID = #id)
while #selectID <> 'NULL'
begin
set #id = ''
while #i < 5
begin
set #id = #id + substring(#chars, cast(ceiling(rand() * 26) as int), 1)
set #i = #i + 1
end
SET #selectID = (SELECT CustomerID FROM CUSTOMERS WHERE CustomerID = #id)
SELECT #id
end
end
Here is the insert procedure I have at the moment
CREATE PROCEDURE [dbo].[InsertCustomers]
(
#CustomerID nchar(5),
#CompanyName nvarchar(40),
#ContactName nvarchar(30) = NULL,
#ContactTitle nvarchar(30) = NULL,
#Address nvarchar(60) = NULL,
#City nvarchar(15) = NULL,
#Region nvarchar(15) = NULL,
#PostalCode nvarchar(10) = NULL,
#Country nvarchar(15) = NULL,
#Phone nvarchar(24) = NULL,
#Fax nvarchar(24) = NULL
)
AS
SET NOCOUNT OFF;
INSERT INTO [dbo].[Customers] ([CustomerID], [CompanyName], [ContactName], [ContactTitle], [Address], [City], [Region], [PostalCode], [Country], [Phone], [Fax]) VALUES (#CustomerID, #CompanyName, #ContactName, #ContactTitle, #Address, #City, #Region, #PostalCode, #Country, #Phone, #Fax);
The main problem here is that the incremental cost of detecting collisions from the generated string, and try again, increases as you generate more and more strings (since you have to read all of those strings to make sure you didn't generate a duplicate). At the same time, the odds of hitting a duplicate goes up, meaning the bigger the table gets, the slower this process will get.
Why do you need to generate the unique string at runtime? Build them all in advance. This article and this post are about random numbers, but the basic concept is the same. You build up a set of unique strings and pull one off the stack when you need one. Your chance of collisions stays constant at 0% throughout the lifetime of the application (provided you build up a stack of enough unique values). Pay for the cost of collisions up front, in your own setup, instead of incrementally over time (and at the cost of a user waiting for those attempts to finally yield a unique number).
This will generate 100,000 unique 5-character strings, at the low, one-time cost of about 1 second (on my machine):
;WITH
a(a) AS
(
SELECT TOP (26) number + 65 FROM master..spt_values
WHERE type = N'P' ORDER BY number
),
b(a) AS
(
SELECT TOP (10) a FROM a ORDER BY NEWID()
)
SELECT DISTINCT CHAR(b.a) + CHAR(c.a) + CHAR(d.a) + CHAR(e.a) + CHAR(f.a)
FROM b, b AS c, b AS d, b AS e, b AS f;
That's not enough? You can generate about 1.12 million unique values by changing TOP (10) to TOP (20). This took 18 seconds. Still not enough? TOP (24) will give you just under 8 million in about 2 minutes. It will get exponentially more expensive as you generate more strings, because that DISTINCT has to do the same duplicate checking you want to do every single time you add a customer.
So, create a table:
CREATE TABLE dbo.StringStack
(
ID INT IDENTITY(1,1) PRIMARY KEY,
String CHAR(5) NOT NULL UNIQUE
);
Insert that set:
;WITH
a(a) AS
(
SELECT TOP (26) number + 65 FROM master..spt_values
WHERE type = N'P' ORDER BY number
),
b(a) AS
(
SELECT TOP (10) a FROM a ORDER BY NEWID()
)
INSERT dbo.StringStack(String)
SELECT DISTINCT CHAR(b.a) + CHAR(c.a) + CHAR(d.a) + CHAR(e.a) + CHAR(f.a)
FROM b, b AS c, b AS d, b AS e, b AS f;
And then just create a procedure that pops one off the stack when you need it:
CREATE PROCEDURE dbo.AddCustomer
#CustomerName VARCHAR(64) /* , other params */
AS
BEGIN
SET NOCOUNT ON;
DELETE TOP (1) dbo.StringStack
OUTPUT deleted.String, #CustomerName /* , other params */
INTO dbo.Customers(CustomerID, CustomerName /*, ...other columns... */);
END
GO
No silly looping, no needing to check if the CustomerID you generated just exists, etc. The only additional thing you'll want to build is some type of check that notifies you when you're getting low.
As an aside, these are terrible identifiers for a CustomerID. What is wrong with a sequential surrogate key, like an IDENTITY column? How is a 5-digit random string with all this effort involved, any better than a unique number the system can generate for you much more easily?
Muhammed Ali 's answer works, but will prove rather ressource intensive (especially when there aren't many combinations of 5 letters left to use) : your function uses the random generator, and it will take it a while to find a combination that isn't used, especially since it has a very limited memory of its previous results.
This means it will try, and might give you something of the sort (exaggerating a bit) : BAGER the first time, then ANSWE the second time, then again BAGER the third time. You see you will lose a good amount of time with the generator giving you the same answer over and over again (especially over 12M possible combinations).
If you are looking for a fixed length ID (since you use NCHAR(5), I guess that's a good assumption), I would rather look into building a table that contains all the possible combinations, and pick one value of this table every time you need one. You would delete it once it got used, or mark it as used (which I would prefer, for reuseability reasons).
This leads to my final comment (which I cannot put as comment 'cause I don't have enough reputation) : why not use the IDENTITY function provided by MS-SQL ? This provides a much better handling of the Primary key generation...
I believe you can do something like this to make sure you all get a unique id
begin
declare #chars char(26) = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
declare #i int = 0
declare #id varchar(max) = ''
while (1=1)
begin
set #id = #id + substring(#chars, cast(ceiling(rand() * 26) as int), 1)
set #i = #i + 1
IF (NOT EXISTS(SELECT * FROM Customers WHERE CustomerID = #id) AND LEN(#id) = 5)
BREAK
ELSE
CONTINUE
end
Select (cast(#id as nvarchar(400)))
end
Set the while condition to be always true and break out of while loop only when both of your requirements are TRUE i.e Length of new ID is 5 and it does not exist in the customers table already.
I have a stored procedure which needs a different if condition to work properly.
The procedure has 2 parameter namely, #CategoryID and #ClassID, which basically come from a UI tree view functionality. #CategoryID corresponds to the parent nodes, while #ClassID corresponds to the child nodes.
Based upon the above parameters I need to make a selection(Column Code) from a table which has CategoryID and ClassID as columns.
Now there are 2 scenarios:
Scenario 1
#CategoryID:A
#ClassID:B (which is a child node of CategoryID A)
Result needed: Codes corresponding to only ClassID B, which is basically the intersection
Scenario 2
#CategoryID:A
#ClassID: C (which is not a child node for CategoryID A)
Result needed: Codes corresponding to the CategoryID A, as well as ClassID B, basically a union
The procedure which I wrote gives me correct answer for the second scenario, but the first scenario it fails. Below is my procedure:
ALTER PROCEDURE [dbo].[uspGetCodes]
#CategoryID varchar(50),
#ClassID varchar(50)
AS
BEGIN
BEGIN TRY
DECLARE #SQLQuery NVARCHAR(MAX)
SET #SQLQuery=N'SELECT Code FROM dbo.ClassToCategoryMapping WHERE '
IF (#CategoryID IS NULL OR #CategoryID='')
BEGIN
SET #SQLQuery=#SQLQuery + 'ClassId IN ('+#ClassID+')'
PRINT(#SQLQuery)
EXEC(#SQLQuery)
END
ELSE IF (#ClassID IS NULL OR #ClassID='')
BEGIN
SET #SQLQuery=#SQLQuery+'CategoryID IN ('+#CategoryID+')'
PRINT(#SQLQuery)
EXEC(#SQLQuery)
END
ELSE
BEGIN
SET #SQLQuery=#SQLQuery+'(CategoryID IN ('+#CategoryID+') OR ClassId IN ('+#ClassID+') )'
PRINT(#SQLQuery)
EXEC(#SQLQuery)
END
END TRY
BEGIN CATCH
SELECT ERROR_NUMBER() AS 'ErrorNumber', ERROR_MESSAGE() AS 'ErrorMessage', ERROR_SEVERITY() AS 'ErrorSeverity', ERROR_STATE() AS 'ErrorState', ERROR_LINE() AS 'ErrorLine'
RETURN ERROR_NUMBER()
END CATCH
END
The Last Else part actually does an 'OR', which gives me the union of the Codes for CategoryID's and ClassID's irrespective whether the given ClassID is a child of the given CategoryID or not.
My question over here would be, how to write the condition to achieve both the scenarios.
Latest Sample Data:
Scenario 1
#CategoryId=2,5, #ClassID=10 (Here 10 is the child while 2 is the parent, CategoryID 2 corresponds to ClassID's 10, 11, 12)
Expected Result: 10, 26, 27 (26 and 27 correspond to the CategoryID 5)
Scenario 2
#CategoryID=2, #ClassID=13,15 (13 and 15 is the child of a different parent, CategoryID 2 corresponds to ClassID's 10, 11 ,12)
Expected Result: 10, 11, 12, 13, 15
Data in Table dbo.ClasstoCategoryMapping will be somewhat as below:
CategoryID ClassID Code
2 10 200
2 11 201
2 12 202
5 26 501
5 27 502
6 15 601
6 16 602
6 17 603
7 20 701
7 21 702
7 22 703
I guess I have made my question quite clear, if no then, folks can ask me to edit it. I would be happy to do so. I urge the experts to assist me in this problem. Any pointers too will be quite appreciated.
Regards
Anurag
If I understand the question correctly, what you require in your result set is:
(all supplied classid) + (all classid for supplied categoryid with no matching supplied classid)
That would translate to the following:
CREATE PROCEDURE [dbo].[uspGetCodes]
(
#CategoryID varchar(50),
#ClassID varchar(50)
)
AS
BEGIN
SELECT COALESCE(CM.CategoryID, CM2.CategoryID) AS CategoryID,
COALESCE(CM.ClassID, CM2.ClassID) AS ClassID,
COALESCE(CM.Code, CM2.Code) AS Code
--Matched classIDs:
FROM dbo.udfSplitCommaSeparatedIntList(#ClassID) CLAS
JOIN dbo.ClassToCategoryMapping CM
ON CM.ClassId = CLAS.Value
--Unmatched CategoryIDs:
FULL
OUTER
JOIN dbo.udfSplitCommaSeparatedIntList(#CategoryID) CAT
ON CM.CategoryID = CAT.Value
LEFT
JOIN dbo.ClassToCategoryMapping CM2
ON CM.CategoryID IS NULL
AND CM2.CategoryID = CAT.Value
END
I have included Category, Class and Code in the result since its easier to see what's going on, however I guess you only really need code
This makes use of the following function to split the supplied comma separated strings:
CREATE FUNCTION [dbo].[udfSplitCommaSeparatedIntList]
(
#Values varchar(50)
)
RETURNS #Result TABLE
(
Value int
)
AS
BEGIN
DECLARE #LengthValues int
SELECT #LengthValues = COALESCE(LEN(#Values), 0)
IF (#LengthValues = 0)
RETURN
DECLARE #StartIndex int
SELECT #StartIndex = 1
DECLARE #CommaIndex int
SELECT #CommaIndex = CHARINDEX(',', #Values, #StartIndex)
DECLARE #Value varchar(50);
WHILE (#CommaIndex > 0)
BEGIN
SELECT #Value = SUBSTRING(#Values, #StartIndex, #CommaIndex - #StartIndex)
INSERT #Result VALUES (#Value)
SELECT #StartIndex = #CommaIndex + 1
SELECT #CommaIndex = CHARINDEX(',', #Values, #StartIndex)
END
SELECT #Value = SUBSTRING(#Values, #StartIndex, LEN(#Values) - #StartIndex + 1)
INSERT #Result VALUES (#Value)
RETURN
END
this is the sample query that can achieve your goal, is this what you want?
DECLARE #SAMPLE TABLE
(
ID INT IDENTITY(1,1),
CategoryId INT,
ClassID INT
)
INSERT INTO #sample
VALUES(2,10)
INSERT INTO #sample
VALUES(2,11)
INSERT INTO #sample
VALUES(2,12)
INSERT INTO #sample
VALUES(3,13)
DECLARE #CategoryID INT
DECLARE #ClassID Int
--Play around your parameter(s) here
SET #CategoryID = 2
SET #ClassID = 13
--Snenario 1
--#CategoryId=2, #ClassID=10 (Here 10 is the child while 2 is the parent, CategoryID 2 corresponds to ClassID's 10, 11, 12)
--Expected Result: 10
IF EXISTS(SELECT * FROM #SAMPLE WHERE CategoryId = #CategoryID AND ClassID = #ClassID)
SELECT ClassID FROM #SAMPLE WHERE CategoryId = #CategoryID AND ClassID = #ClassID
--Scenario 2
--#CategoryID=2, #ClassID=13 (13 is the child of a different parent, CategoryID 2 corresponds to ClassID's 10, 11 ,12)
--Expected Result: 10, 11, 12, 13
ELSE
SELECT ClassID FROM #SAMPLE WHERE ClassID = #ClassID OR CategoryId = #CategoryID
Try this
select * from yourtable
where CategoryId = #CategoryID and ClassID = #ClassID
union
select * from
(
select * from yourtable where ClassID = #ClassID
union
select * from yourtable where CategoryId = #CategoryID
) v
where not exists (select * from yourtable where CategoryId = #CategoryID and ClassID = #ClassID)
UPDATE FOR DELIMITED STRING
If you have a comma delimited string then it is best to use a CLR function to create the table, but you could use a SQL function. Examples of how to do this are easy to find with a Google search... but for reference here is one good article on the subject -> http://www.sqlperformance.com/2012/07/t-sql-queries/split-strings I expect at some point there will be native support on most platforms.
Given that you have a function that returns a table of one column (named ID) of type int, or an empty table on a null input. Note: You may have to have the null return a table with one row containing an invalid value (a value that will never join), say -1.
The code is as simple as this:
SELECT Code
FROM ClassToCategoryMapping
LEFT JOIN MakeTableFromCVS(#CategoryID) AS CatTable
ON CatTable.ID = CategoryID
LEFT JOIN MakeTableFromCVS(#ClassID) AS ClassTable
ON ClassTable.ID = ClassID
WHERE
CASE
WHEN #CatgoryID IS NULL THEN -1 ELSE CatTable.ID
END = ISNULL(CatTable.ID,-1)
AND
CASE
WHEN #ClassID IS NULL THEN -1 ELSE ClassTable.ID
END = ISNULL(ClassTable.ID,-1)
AND
COALESCE(CatTable.ID,ClassTable.ID,-1) != -1
The logic is the same as below. Because the join will vary the values if it is not null we have to use a different trick. Here we use a marker value (in this case -1) to signal the null value. Any value that won't appear in the comma separated list will work as this marker value, remember it must be of the same type.
You don't need dynamic SQL here and you will find SQL server is better at optimizing if you don't use dynamic SQL. In fact, you don't even need an if statement If you can be sure the input is always null you can do this:
SELECT Code
FROM ClassToCategoryMapping
WHERE
How this works
This query checks for both CategoryID and ClassID columns match the incoming parameters but "ignores" the input when they are null by checking the column against itself. This is an handy SQL trick.
Note if you do need to check for empty strings then this will be almost as fast
DECLARE #myCatID varchar(max)
DECLARE #myClassID varchar(max)
SET #myCatID = #CategoryID
SET #myClassID = #ClassID
IF LTRIM(RTRIM(#CategoryID) = '' THEN SET #myCatID = NULL
IF LTRIM(RTRIM(#ClassID) = '' THEN SET #myClassID = NULL
SELECT Code
FROM ClassToCategoryMapping
WHERE CatgoryID = ISNULL(#myCatID,CategoryID)
AND ClassID = ISNULL(#myClassID,ClassID)
You can replace ISNULL() with COALESCE() if you want... they do the same thing in this case.
I am trying to achieve something like the below in WHERE clause in sql.
if (#zipCode ==null)
begin
([Portal].[dbo].[Address].Position.Filter(#radiusBuff) = 1)
end
else if(#zipCode !=null)
begin
([Portal].[dbo].[Address].PostalCode=#zipCode )
end
I tried the following:
WHERE ((#zipCode IS NOT NULL AND ([Portal].[dbo].[Address].PostalCode=#zipCode)) OR (#zipCode IS NULL AND ([Portal].[dbo].[Address].Position.Filter(#radiusBuff) = 1)))
which is wrong. Can anyone help in framing the exact statement. Thanks!
is null is the syntax I use for such things, when COALESCE is of no help.
Try:
if (#zipCode is null)
begin
([Portal].[dbo].[Address].Position.Filter(#radiusBuff) = 1)
end
else
begin
([Portal].[dbo].[Address].PostalCode=#zipCode )
end
Isnull() syntax is built in for this kind of thing.
declare #Int int = null;
declare #Values table ( id int, def varchar(8) )
insert into #Values values (8, 'I am 8');
-- fails
select *
from #Values
where id = #Int
-- works fine
select *
from #Values
where id = isnull(#Int, 8);
For your example keep in mind you can change scope to be yet another where predicate off of a different variable for complex boolean logic. Only caveat is you need to cast it differently if you need to examine for a different data type. So if I add another row but wish to specify int of 8 AND also the reference of text similar to 'repeat' I can do that with a reference again back to the 'isnull' of the first variable yet return an entirely different result data type for a different reference to a different field.
declare #Int int = null;
declare #Values table ( id int, def varchar(16) )
insert into #Values values (8, 'I am 8'), (8, 'I am 8 repeat');
select *
from #Values
where id = isnull(#Int, 8)
and def like isnull(cast(#Int as varchar), '%repeat%')
is null can be used to check whether null data is coming from a query as in following example:
declare #Mem varchar(20),#flag int
select #mem=MemberClub from [dbo].[UserMaster] where UserID=#uid
if(#Mem is null)
begin
set #flag= 0;
end
else
begin
set #flag=1;
end
return #flag;
Try a case statement
WHERE
CASE WHEN #zipCode IS NULL THEN 1
ELSE #zipCode
END
Try the following:
if ((select VisitCount from PageImage where PID=#pid and PageNumber=5) is NULL)
begin
update PageImage
set VisitCount=1
where PID=#pid and PageNumber=#pageno
end
else
begin
update PageImage
set VisitCount=VisitCount+1
where PID=#pid and PageNumber=#pageno
end
I am currently developing on an advertising system, which have been running just fine for a while now, apart from recently when our views per day have shot up from about 7k to 328k. Our server cannot take the pressure on this anymore - and knowing that I am not the best SQL guy around (hey, I can make it work, but not always in the best way) I am asking here for some optimization guidelines. I hope that some of you will be able to give rough ideas on how to improve this - I don't specifically need code, just to see the light :).
As it is at the moment, when an advert is supposed to be shown a PHP script is called, which in return calls a stored procedure. This stored procedure does several checks, it tests up against our customer database to see if the person showing the advert (given by a primary key id) is an actual customer under the given locale (our system is running on several languages which are all run as separate sites). Next up is all the advert details fetched out (image location as an url, height and width of the advert) - and lest step calls a separate stored procedure to test if the advert is allowed to be shown (is the campaign expired by either date or number of adverts allowed to show?) and if the customer has access to it (we got 2 access systems running, a blacklist and a whitelist one) and lastly what type of campaign we're running, is the view unique and so forth.
The code consists of a couple of stored procedures that I will post in here.
--- procedure called from PHP
CREATE PROCEDURE [dbo].[ExecView]
(
#publisherId bigint,
#advertId bigint,
#localeId int,
#ip varchar(15),
#ipIsUnique bit,
#success bit OUTPUT,
#campaignId bigint OUTPUT,
#advert varchar(500) OUTPUT,
#advertWidth int OUTPUT,
#advertHeight int OUTPUT
)
AS
BEGIN
SET NOCOUNT ON;
DECLARE #unique bit
DECLARE #approved bit
DECLARE #publisherEarning money
DECLARE #advertiserCost money
DECLARE #originalStatus smallint
DECLARE #advertUrl varchar(500)
DECLARE #return int
SELECT #success = 1, #advert = NULL, #advertHeight = NULL, #advertWidth = NULL
--- Must be valid publisher, ie exist and actually be a publisher
IF dbo.IsValidPublisher(#publisherId, #localeId) = 0
BEGIN
SELECT #success = 0
RETURN 0
END
--- Must be a valid advert
EXEC #return = FetchAdvertDetails #advertId, #localeId, #advert OUTPUT, #advertUrl OUTPUT, #advertWidth OUTPUT, #advertHeight OUTPUT
IF #return = 0
BEGIN
SELECT #success = 0
RETURN 0
END
EXEC CanAddStatToAdvert 2, #advertId, #publisherId, #ip, #ipIsUnique, #success OUTPUT, #unique OUTPUT, #approved OUTPUT, #publisherEarning OUTPUT, #advertiserCost OUTPUT, #originalStatus OUTPUT, #campaignId OUTPUT
IF #success = 1
BEGIN
INSERT INTO dbo.Stat (AdvertId, [Date], Ip, [Type], PublisherEarning, AdvertiserCost, [Unique], Approved, PublisherCustomerId, OriginalStatus)
VALUES (#advertId, GETDATE(), #ip, 2, #publisherEarning, #advertiserCost, #unique, #approved, #publisherId, #originalStatus)
END
END
--- IsValidPublisher
CREATE FUNCTION [dbo].[IsValidPublisher]
(
#publisherId bigint,
#localeId int
)
RETURNS bit
AS
BEGIN
DECLARE #customerType smallint
DECLARE #result bit
SET #customerType = (SELECT [Type] FROM dbo.Customer
WHERE CustomerId = #publisherId AND Deleted = 0 AND IsApproved = 1 AND IsBlocked = 0 AND LocaleId = #localeId)
IF #customerType = 2
SET #result = 1
ELSE
SET #result = 0
RETURN #result
END
-- Fetch advert details
CREATE PROCEDURE [dbo].[FetchAdvertDetails]
(
#advertId bigint,
#localeId int,
#advert varchar(500) OUTPUT,
#advertUrl varchar(500) OUTPUT,
#advertWidth int OUTPUT,
#advertHeight int OUTPUT
)
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
SELECT #advert = T1.Advert, #advertUrl = T1.TargetUrl, #advertWidth = T1.Width, #advertHeight = T1.Height FROM Advert as T1
INNER JOIN Campaign AS T2 ON T1.CampaignId = T2.Id
WHERE T1.Id = #advertId AND T2.LocaleId = #localeId AND T2.Deleted = 0 AND T2.[Status] <> 1
IF #advert IS NULL
RETURN 0
ELSE
RETURN 1
END
--- CanAddStatToAdvert
CREATE PROCEDURE [dbo].[CanAddStatToAdvert]
#type smallint, --- Type of stat to add
#advertId bigint,
#publisherId bigint,
#ip varchar(15),
#ipIsUnique bit,
#success bit OUTPUT,
#unique bit OUTPUT,
#approved bit OUTPUT,
#publisherEarning money OUTPUT,
#advertiserCost money OUTPUT,
#originalStatus smallint OUTPUT,
#campaignId bigint OUTPUT
AS
BEGIN
SET NOCOUNT ON;
DECLARE #campaignLimit int
DECLARE #campaignStatus smallint
DECLARE #advertsLeft int
DECLARE #campaignType smallint
DECLARE #campaignModeration smallint
DECLARE #count int
SELECT #originalStatus = 0
SELECT #success = 1
SELECT #approved = 1
SELECT #unique = 1
SELECT #campaignId = CampaignId FROM dbo.Advert
WHERE Id = #advertId
IF #campaignId IS NULL
BEGIN
SELECT #success = 0
RETURN
END
SELECT #campaignLimit = Limit, #campaignStatus = [Status], #campaignType = [Type], #publisherEarning = PublisherEarning, #advertiserCost = AdvertiserCost, #campaignModeration = ModerationType FROM dbo.Campaign
WHERE Id = #campaignId
IF (#type <> 0 AND #type <> 2 AND #type <> #campaignType) OR ((#campaignType = 0 OR #campaignType = 2) AND (#type = 1)) -- if not a click or view type, then type must match the campaign (ie, only able to do leads on lead campaigns, no isales or etc), click and view campaigns however can do leads too
BEGIN
SELECT #success = 0
RETURN
END
-- Take advantage of the fact that the variable only gets touched if there is a record,
-- which is supposed to override the existing one, if there is one
SELECT #publisherEarning = Earning FROM dbo.MapCampaignPublisherEarning
WHERE CanpaignId = #campaignId AND PublisherId = #publisherId
IF #campaignStatus = 1
BEGIN
SELECT #success = 0
RETURN
END
IF NOT #campaignLimit IS NULL
BEGIN
SELECT #advertsLeft = AdvertsLeft FROM dbo.Campaign WHERE Id = #campaignId
IF #advertsLeft < 1
BEGIN
SELECT #success = 0
RETURN
END
END
IF #campaignModeration = 0 -- blacklist
BEGIN
SELECT #count = COUNT([Status]) FROM dbo.MapCampaignModeration WHERE CampaignId = #campaignId AND PublisherId = #publisherId AND [Status] = 3
IF #count > 0
BEGIN
SELECT #success = 0
RETURN
END
END
ELSE -- whitelist
BEGIN
SELECT #count = COUNT([Status]) FROM dbo.MapCampaignModeration WHERE CampaignId = #campaignId AND PublisherId = #publisherId AND [Status] = 2
IF #count < 1
BEGIN
SELECT #success = 0
RETURN
END
END
IF #ipIsUnique = 1
BEGIN
SELECT #unique = 1
END
ELSE
BEGIN
IF (SELECT COUNT(T1.Id) FROM dbo.Stat AS T1
INNER JOIN dbo.IQ_Advert AS T2
ON T1.AdvertId = T2.Id
WHERE T2.CampaignId = #campaignId
AND T1.[Type] = #type
AND T1.[Unique] = 1
AND T1.PublisherCustomerId = #publisherId
AND T1.Ip = #ip
AND DATEADD(SECOND, 86400, T1.[Date]) > GETDATE()
) = 0
SELECT #unique = 1
ELSE
BEGIN
SELECT #unique = 0, #originalStatus = 1 -- not unique, and set status to be ip conflict
END
END
IF #unique = 0 AND #type <> 0 AND #type <> 2
BEGIN
SELECT #unique = 1, #approved = 0
END
IF #originalStatus = 0
SELECT #originalStatus = 5
IF #approved = 0 OR #type <> #campaignType
BEGIN
SELECT #publisherEarning = 0, #advertiserCost = 0
END
END
I am thinking this needs more than just a couple of indexes thrown in to help it, but rather a total rethinking of how to handle it. I have been heard that running this as a batch would help, but I am not sure how to get this implemented, and really not sure if i can implement it in a such way where I keep all these nice checks before the actual insert or if I have to give up on some of this.
Anyhow, all help would be appreciated, if you need any of the table layouts, let me know :).
Thanks for taking the time to look at it :)
Make sure to reference tables with the ownership prefix. So instead of:
INNER JOIN Campaign AS T2 ON T1.CampaignId = T2.Id
Use
INNER JOIN dbo.Campaign AS T2 ON T1.CampaignId = T2.Id
That will allow the database to cache the execution plan.
Another possibility is to disable database locking, which has data integrity risks, but can significantly increase performance:
INNER JOIN dbo.Campaign AS T2 (nolock) ON T1.CampaignId = T2.Id
Run a sample query in SQL Analyzer with "Show Execution Plan" turned on. This might give you a hint as to the slowest part of the query.
it seems like FetchAdvertDetails hit the same tables as the start of CanAddStatToAdvert (Advert and Campaign). If possible, I'd try to eliminate FetchAdvertDetails and roll its logic into CanAddStatToAdvert, so you don't have the hit Advert and Campaign the extra times.
Get rid of most of the SQL.
This stored procedure does several
checks, it tests up against our
customer database to see if the person
showing the advert (given by a primary
key id) is an actual customer under
the given locale (our system is
running on several languages which are
all run as separate sites). Next up is
all the advert details fetched out
(image location as an url, height and
width of the advert) - and lest step
calls a separate stored procedure to
test if the advert is allowed to be
shown (is the campaign expired by
either date or number of adverts
allowed to show?) and if the customer
has access to it (we got 2 access
systems running, a blacklist and a
whitelist one) and lastly what type of
campaign we're running, is the view
unique and so forth.
Most of this should not be done in the database for every request. In particular:
Customer and local can be stored in memory. Expire them after 5 minutes or so, but do not ask for this info on every repetitive request.
Advert details can also be stored. Every advert will have a "key" to identify it (Number)?. Ust a dictionary / hashtable in memory.
Eliminate as many SQL Parts as you can. Dumping repetitive work on the SQL Database is a typical mistake.