Multiplication By Row Without A Cursor? Myth Or Madness?
Jun 15, 2004
Hi all...I have a friend who has a problem I'm trying to help with (no...REALLY...it's a FRIEND, not ME!!! *LOL*)
I haven't run across the need...but in a nutshell...we have a table with many rows of data, one column in each row needs to be multiplied by all other same-columns in the table's other rows.
For example...
MyKey int, MyFloat float(53)
I want to multiply Myfloat by all other Myfloat columns in the table.
Similar to SUM(MyFloat) but something like PRODUCT(MyFloat).
Is there a aggregate kept in a basement closet somewhere, or a way to perform this operation rather than using a cursor to do it:
An example of my table:
1 3.2
2 4.1
3 7.1
if I could do a PRODUCT(MyFloat) I would want the result to be (3.2 X 4.1 X 7.1) or 93.152
Hello. I have the below INSERT statement in an application, which works fine. However, I can't figure out how to insert data into a new column. The new column is text3, and the text would be TextBox4.Text + / + TextBox5.Text + / + TextBox6.Text + / TextBox7.Text. Where the "/" is text and not an operator. Every syntax I try doesn't work. Any ideas would be appreciated! INSERT INTO table (updateTime, text4, text5, text6, text7, updateTime1) VALUES (getdate(), '" + this.TextBox4.Text + "', '" + this.TextBox5.Text + "', '" + this.TextBox6.Text + "', '" + this.TextBox7.Text + "', CONVERT(VARCHAR(19), GETDATE(), 120) + Space(2) )
I've never been able to get to it. I must admit my first few attempts were before I had properly configured Reporting Services. But after two fresh installs, including a fresh OS install (64 bit Vista Ultimate) I still can't get to Report Manager. The closest I've been able to come is this error message:
Error
The report server is not responding. Verify that the report server is running and can be accessed from this computer.
Home
The service is running and I'm on my local computer which I have admin rights. I'm stumped.
Hello, I'll try to make the description of this multi-problem scenario as short and sweet as possible.
First Problem The default named instance of "SQLEXPRESS" was somehow installed on my machine and nothing can get rid of it. However, it is somehow invisible to everything else on my system, so I can't use it. How do I get rid of the instance or repair it?
Second problem I installed another instance of the SQL Server 2005 Express and named it, "SQLEXPRESS02". I attached a database to it and successfully retrieved data from it using an application that used the following connection string:
Data Source=(local)sqlexpress02;AttachDbFilename=|DataDirectory|MyDatabase.mdf;Initial Catalog=MyDatabase;Integrated Security=True;User Instance=True
Next, I tried to use a different application to retrieve data from a copy of the same database located in a different directory and used the same connection string as that shown above. When I do this, I receive an error message similar to the following:
Database 'C:PathToMyOriginalProjectinDebugMyDatabase.mdf' already exists. Choose a different database name.
Cannot attach the file 'C:PathToMyNewProjectinDebugMyDatabase.mdf' as database 'MyDatabase'.
I then tried, out of curiosity, to change the Initial Catalog portion of the connection string to "MyDatabase2" and attempt the data retrieval again. The connection string looked like this:
Data Source=(local)sqlexpress02;AttachDbFilename=|DataDirectory|MyDatabase.mdf;Initial Catalog=MyDatabase2;Integrated Security=True;User Instance=True
Interestingly enough, it worked. However, when I switched back to the original connection string, I got the same error message as before.
What's going on here? I thought that one of the virtues of user instances was that they would attach at run-time, then disconnect when the application was through with them. If that's the case, then why am I getting errors stating that a database of the same name is already attached? Is there a way to detach these databases from a user instance? Can it be done by some value in the connection string?
Hi GuysI don't want to keep asking for your help all the time on each individualquery, so could you please help me to break the myths on the following:1) I have 2 tables. Once is called ACCOUNTS and the other ACCOUNTBUDGET.ACCOUNTS includes all of the usual details for customers and suppliers, egthe account code (as ACCOUNTID), the account name (as NAME), etc.ACCOUNTBUDGET basically holds a transaction line for each month and it'scorresponding year to store the turnover for that month, eg one row containsACCOUNTID, PERIOD (ie the month), YEAR and TURNOVER.Now a lot of the SQL 6.5 tables that I deal with are in this vein and theusual query is that I want to list all of the ACCOUNTIDs and NAMEs thatexist in the ACCOUNTS table and then show for example what their TURNOVER isfor a applicable PERIOD and YEAR, which are all held in the ACCOUNTSBUDGETtable.Now if I do a quick query using MS Query all I get are rows that haverelated values in both the ACCOUNTS and ACCOUNTSBUDGET table when I havespecified say a certain PERIOD and YEAR.The main point of my current reporting problem is that I want to show allthe ACCOUNTIDs and NAMEs in ACCOUNTS that have zero TURNOVER for aparticular PERIOD and YEAR.I'm positive that I have to create a 2 step query/join, but I don't know howto do it. What is the method? People in this NG, can rattle one up inseconds, but I just don't see the logic. Can you help me with this queryand let me know how you manage to fathom it.2) Are there any good web sites that explain in kiddie form how to do thissort of thing?I really appreciate your help on this.RegardsLaphan
For entertainment purposes, I've been reading some articles on SQL Injection Attacks and there should be a cover charge to read these articles. (excuse the sarcasm)
Most defense is based on the use of stored procedures or read only settings on the tables.
I'm looking for practical opinions and possibly some code that would convince me personally that this is indeed a real threat.
Also, if possible, please post remedies that are solid and not open ended.
Does multiplication with 1 affect query performance?I have a a stored procedure that converts results to another unit if required. In alternative 1 below, the results are returned with a separate select statement if no conversion is necessary - in other words, no multiplication with a conversion factor is required. However, the code is not very nice since I need to repeat the select statement again in case a conversion is required, this time including the conversion factor.Alternative 2 uses cleaner-looking code. The conversion factor is set to 1 if no conversion is required, and a single SELECT statement is used to return the data. The @factor variable is defined as a float.I would rather use alternative 2, but I wonder if there is any performance penalty for doing that if no conversion is required since the results are always multiplied with the @factor? Or can SQL server somehow understand that @factor = 1 and no multiplication is required?--- Alternative 1: ---IF @fromunit_sid = @tounit_sid-- Return unconverted results SELECT ISNULL(ls_totalWaterConsumption,0) AS ls_totalWaterConsumption,ls_theoreticalWaterConsumption AS ls_theoretical_WaterConsumption,ls_totalWaterConsumption - ls_theoreticalWaterConsumption AS ls_extra_WaterConsumption FROM Results WHERE scenario_id = @scenario_idELSEBEGIN -- Get conversion factor EXEC getConversionFactor @fromunit_sid, @tounit_sid, @factor OUTPUT -- Get the converted results SELECT ISNULL(ls_totalWaterConsumption * @factor,0) AS ls_totalWaterConsumption, ls_theoreticalWaterConsumption * @factor AS ls_theoretical_WaterConsumption, (ls_totalWaterConsumption - ls_theoreticalWaterConsumption) * @factor AS ls_extra_WaterConsumptionFROM Results WHERE scenario_id = @scenario_idEND --- Alternative 2: ---IF @fromunit_sid = @tounit_sidSET @factor = 1ELSE -- Get conversion factor EXEC getConversionFactor @fromunit_sid, @tounit_sid, @factor OUTPUT
-- Get the converted results SELECT ISNULL(ls_totalWaterConsumption * @factor,0) AS ls_totalWaterConsumption, ls_theoreticalWaterConsumption * @factor AS ls_theoretical_WaterConsumption, (ls_totalWaterConsumption - ls_theoreticalWaterConsumption) * @factor AS ls_extra_WaterConsumptionFROM Results WHERE scenario_id = @scenario_id And another question: is using an IF function considerably faster than making a call to another stored procedure?In alternative 2 above I use an IF statement to check if @fromunit_sid = @tounit_sid, and . But in fact the function getConversionFactor that I'm calling does exactly the same thing: if I pass in identical from- and to-values, it simply returns 1, so I could omit the IF statement completely and just use alternative 3. But is it slower?--- Alternative 3 -- Get conversion factor EXEC getConversionFactor @fromunit_sid, @tounit_sid, @factor OUTPUT
I am currently building a website to deal with different product information and sales with php. I am using SQL to sort the database and pull out information.
The final thing i need to do is work out the total revenue of each product however the problem i am having is that the 'Price' column and 'SalesVolume' column are in two different tables and they need to be multiplied together.
The two tables and column headings are as follows:
Product ID Name Price
MonthlySales ID ProductCode Month Year SalesVolume
(ID and ProductCode are linked together in a relationship)
I cannot see anything wrong with the syntax in my query however i believe there is.
Here is the query I am using:
Code: "SELECT SUM(Products.Price * SUM(MonthlySales.SalesVolume)) as revenue FROM Products INNER JOIN MonthlySales ON(Products.ProductCode = MonthlySales.id) GROUP BY Products.ProductCode";
I'm trying to create a case statement that if a field = a certain code, I'd like to take another field * 0.9. But, I'm getting a Null value for the answer..here is the statement:,case when parts.ndc = '50242-0138-01' then labels.BAGSDISP*0.9 end "Units Dispensed"..For this example labels.BAGSDISP is a value of 2. So, in theory it should be 2 * 0.9 and the result should be 1.8 but I'm getting a NULL
Suppose I have users that can belong to organizations. Organizationsare arranged in a tree. Each organization has only one parentorganization but a user maybe a member of multiple organizations.The problem that I'm facing that both organizations and individualusers may have relationships with other entities which aresemantically the same. For instance, an individual user can purchasethings and so can an organization. An individual user can havebusiness partners and so can an organization. So it seems that I wouldneed to have a duplicate set of link tables that link a user to apurchase and then a parallel link table linking an organization to apurchase. If I have N entities with which both users and organizationsmay have relationships then I need 2*N link tables. There is nothingwrong with that per se but just not elegant to have two differenttables for a relationship which is the same in nature, e.g.purchaser->purchaseditem.One other approach I was thinking of is to create an intermediateentity (say it's called "holder") that will be used to hold referencesto all the relationships that both an organization and an individualmay have. There will be 2 link tables linking organizations to"holder" and users to "holder". Holder will in turn reference thepurchases, partners and so on. In this case the number of link tableswill be N+2 as opposed to 2*N but it will have a performance cost ofan extra join.Is there a better way of modelling this notion of 2 different entitiesthat can possess similar relationships with N other entities?
STATIC Defines a cursor that makes a temporary copy of the data to be used by the cursor. All requests to the cursor are answered from this temporary table in tempdb; therefore, modifications made to base tables are not reflected in the data returned by fetches made to this cursor, and this cursor does not allow modifications
It say's that modifications is not allowed in the static cursor. I have a questions regarding that
Static Cursor declare ll cursor global static for select name, salary from ag open ll fetch from ll
while @@FETCH_STATUS=0 fetch from ll update ag set salary=200 where 1=1
close ll deallocate ll
In "AG" table, "SALARY" was 100 for all the entries. When I run the Cursor, it showed the salary value as "100" correctly.After the cursor was closed, I run the query select * from AG.But the result had updated to salary 200 as given in the cursor. file says modifications is not allowed in the static cursor.But I am able to update the data using static cursor.
Hello,I have a test database with table A containing 10,000 rows and a tableB containing 100,000 rows. Rows in B are "children" of rows in A -each row in A has 10 related rows in B (ie. B has a foreign key to A).Using ODBC I am executing the following loop 10,000 times, expressedbelow in pseudo-code:"select * from A order by a_pk option (fast 1)""fetch from A result set""select * from B where where fk_to_a = 'xxx' order by b_pk option(fast 1)""fetch from B result set" repeated 10 timesIn the above psueod-code 'xxx' is the primary key of the current Arow. NOTE: it is not a mistake that we are repeatedly doing the Aquery and retrieving only the first row.When the queries use fast-forward-only cursors this takes about 2.5minutes. When the queries use dynamic cursors this takes about 1 hour.Does anyone know why the dynamic cursor is killing performance?Because of the SQL Server ODBC driver it is not possible to havenested/multiple fast-forward-only cursors, hence I need to exploreother alternatives.I can only assume that a different query plan is getting constructedfor the dynamic cursor case versus the fast forward only cursor, but Ihave no way of finding out what that query plan is.All help appreciated.Kevin
I'm trying to implement a sp_MSforeachsp howvever when I call sp_MSforeach_worker I get the following error can you please explain this problem to me so I can over come the issue.
Msg 16958, Level 16, State 3, Procedure sp_MSforeach_worker, Line 31
Could not complete cursor operation because the set options have changed since the cursor was declared.
Msg 16958, Level 16, State 3, Procedure sp_MSforeach_worker, Line 32
Could not complete cursor operation because the set options have changed since the cursor was declared.
Msg 16917, Level 16, State 1, Procedure sp_MSforeach_worker, Line 153
Cursor is not open.
here is the stored procedure:
Alter PROCEDURE [dbo].[sp_MSforeachsp]
@command1 nvarchar(2000)
, @replacechar nchar(1) = N'?'
, @command2 nvarchar(2000) = null
, @command3 nvarchar(2000) = null
, @whereand nvarchar(2000) = null
, @precommand nvarchar(2000) = null
, @postcommand nvarchar(2000) = null
AS
/* This procedure belongs in the "master" database so it is acessible to all databases */
/* This proc returns one or more rows for each stored procedure */
/* @precommand and @postcommand may be used to force a single result set via a temp table. */
declare @retval int
if (@precommand is not null) EXECUTE(@precommand)
/* Create the select */
EXECUTE(N'declare hCForEachTable cursor global for
DECLARE DBCur CURSOR FOR SELECT U_OB_DB FROM [@OB_TB04_COMPDATA]
OPEN DBCur FETCH NEXT FROM DBCur INTO @DBNAME
WHILE @@FETCH_STATUS = 0 BEGIN
SELECT @SQLCMD = 'SELECT T0.CARDCODE, T0.U_OB_TID AS TRANSID, T0.DOCNUM AS INV_NO, ' + + 'T0.DOCDATE AS INV_DATE, T0.DOCTOTAL AS INV_AMT, T0.U_OB_DONO AS DONO ' + + 'FROM ' + @DBNAME + '.dbo.OINV T0 WHERE T0.U_OB_TID IS NOT NULL' EXEC(@SQLCMD) PRINT @SQLCMD FETCH NEXT FROM DBCur INTO @DBNAME
END
CLOSE DBCur DEALLOCATE DBCur
Part 2
SELECT T4.U_OB_PCOMP AS PARENTCOMP, T0.CARDCODE, T0.CARDNAME, ISNULL(T0.U_OB_TID,'') AS TRANSID, T0.DOCNUM AS SONO, T0.DOCDATE AS SODATE, SUM(T1.QUANTITY) AS SOQTY, T0.DOCTOTAL - T0.TOTALEXPNS AS SO_AMT, T3.DOCNUM AS DONO, T3.DOCDATE AS DO_DATE, SUM(T2.QUANTITY) AS DOQTY, T3.DOCTOTAL - T3.TOTALEXPNS AS DO_AMT INTO #MAIN FROM ORDR T0 JOIN RDR1 T1 ON T0.DOCENTRY = T1.DOCENTRY LEFT JOIN DLN1 T2 ON T1.DOCENTRY = T2.BASEENTRY AND T1.LINENUM = T2.BASELINE AND T2.BASETYPE = T0.OBJTYPE LEFT JOIN ODLN T3 ON T2.DOCENTRY = T3.DOCENTRY LEFT JOIN OCRD T4 ON T0.CARDCODE = T4.CARDCODE WHERE ISNULL(T0.U_OB_TID,0) <> 0 GROUP BY T4.U_OB_PCOMP, T0.CARDCODE,T0.CARDNAME, T0.U_OB_TID, T0.DOCNUM, T0.DOCDATE, T3.DOCNUM, T3.DOCDATE, T0.DOCTOTAL, T3.DOCTOTAL, T3.TOTALEXPNS, T0.TOTALEXPNS
my question is, how to join the part 1 n part 2? is there posibility?
I'm new to cursors, and I'm not sure what's wrong with this code, it run for ever and when I stop it I get cursor open errors
declare Q cursor for select systudentid from satrans
declare @id int
open Q fetch next from Q into @id while @@fetch_status = 0 begin
declare c cursor for
Select b.ssn, SaTrans.SyStudentID, satrans.date, satrans.type, SaTrans.SyCampusID, Amount = Case SaTrans.Type When 'P' Then SaTrans.Amount * -1 When 'C' Then SaTrans.Amount * -1 Else SaTrans.Amount END
From SaTrans , systudent b where satrans.systudentid = b.systudentid
I having a difficult time here trying to figure out what to do here.I need a way to scroll through a recordset and display the resultswith both forward and backward movement on a web page(PHP usingADO/COM)..I know that if I use a client side cursor all the records get shovedto the client everytime that stored procedure is executed..if thisdatabase grows big wont that be an issue?..I know that I can set up a server side cursor that will only send therecord I need to the front end but..Ive been reading around and a lot of people have been saying never touse a server side cursor because of peformance issues.So i guess im weighing network performance needs with the client sidecursor vs server performance with the server side cursor..I am reallyconfused..which one should I use?-Jim
I hope this is the appropriate forum for this question, if not then I apologize. I've got a SQL Server 2000 stored procedure that returns data to be used in a crystal report in Visual Studio 2005. Most of the stored procedure works well, but there is a point where I need to calculate an average number of days been a group of date pairs. I'm not familiar with cursors, but I think that I will need to use one to achieve the result I am looking for so I came up with the code below which is a snippet from my stored procedure. In this part of the code, the sp looks at the temporary table #lmreport (which holds all of the data that is returned at the end to crystal) and for every row in the table where the terrid is 'T' (the territory is domestic), it selects all of those territories from the territory table and loops through them to determine the date averages (by calling a nested stored procedure, also included below) for each territory and then updates #lmreport with that data. When I try to run the stored procedure, I get "The column prefix '#lmreport' does not match with a table name or alias name used in the query." on the line indicated. Does anyone have any idea what might be wrong or if this will even work the way I need it to? Thank you in advance.
I need some help with the concept of a Cursor, as I see it being used in a stored procedure I need to maintain. Here is some code from the stored proc. Can someone tell me what is going on here. I haveleft out some of the sql, but have isolated the Cursor stuff. Open MarketCursor -- How is MarketCursor loaded with data ? FETCH NEXT FROM MarketCursorINTO ItemID, @Item, @Reguest WHILE @@FETCH_STATUS = 0BEGIN
I have something like update table set field = ... where field = ... and for each entry that was effected by this query I want to insert an entry into another table. I have always done this with cursors is there a more effecient way? For some reason cursors run a lot slower on my sql2005 server than the sql2000 server...
hii have creted cursor but i want to use in my asp.net programming when some insert or delete command is work that time i want to excute my cursor how can i do that using asp.net with c# waiting for replaythanks
Hello: I am trying to define a cursor as follows: DECLARE EmployeeList CURSOR FOR dbo.GetRecord(@EmployeeID,@CurrentDate)Can't I use a UDF in the CURSOR FOR ?Help please.thank you.
Hello, I'm trying to construct a cursor that will sequentually increment a number and then update a column with the incremented number. My propblem is that all the rows in the table are being updated with the base number +1. So all rows are updated with 278301. BUT, what I really want is for only the items with adrscode of 'bill to' to be given an incremented number. For example, if there are only five rows of 100 with an adrscode = 'bill to' then only five rows will be updated and the value of the custnmbr should be, 278301, 278302, 278303 ..... I could really use some help with this cursor: Declare @CustomerName as char (60), @seqno as int, @BaseSeqno as intset @Baseseqno = 278300 declare c cursor for select custnmbr from NXOFcustomers Where adrscode = 'BILL TO' order by custnmbropen cfetch next from c into @CustomerNamewhile @@fetch_status=0begin set @seqno = @BaseSeqno + 1 update NXOFcustomers set custnmbr = @seqnoWhere custnmbr = @CustomerName fetch next from c into @CustomerNameend close cdeallocate c
Declare c_cursor Cursor Scroll For Select card_id From cardcreator where card_every_cat = @cat_id Open c_cursor /* Scroll to the randomly selected row and populate into output parameters */ Fetch absolute @iRandomRecord From c_cursor Into @vi_cardid1 print @vi_cardid1 /*Need to check to fetch status if you have reached end of record set begin from first */ select @@fetch_status if (@@fetch_status = 0) Begin Fetch next from c_cursor into @vi_cardid2 print @vi_cardid2 End if (@@fetch_status = 0) Begin Fetch next from c_cursor into @vi_cardid3 End print @vi_cardid3
/* Close and deallocate cursor */ Close c_cursor Deallocate c_cursor
I need to have atleast three records. But if random value starts the cursor at the end, the cursor would not wrap to the beginning.
Is there a way to wrap the cursor to begining if its status is not zero.
I am sure I am not the first one ask this. I have got two tables, what I would like to do now is to update the second table using the values in the first table where T1.id = T2.id, normally I have to use cursor to loop through table two to achieve this. But is it possible to do this without using cursor?
Table 1 has numerous resume's for each person. Each resume has a unique id. ie: Table 1 res_id fname lname userid pwd address city state etc... 100 John Doe jd ok xxxx xxxx xx xxxx 104 Sally May sm sm ccccc cc c cc ccc 643 John Doe jd ok ssss null null 1003 John Doe jd ok 123 elm Nome AK ... 5000 Tom Cat tc tc null null null
I need to insert into Table 2 only the demographic information for each person appearing in Table 1. The catch is that Table 2 doesn't have the same unique id that appears in Table 1. userid and pwd are unique to Table 2 but are numerous in Table 1.
Table 2 new_ident userid pwd address city state etc.. 10 jd ok 123 elm Nome AK .... 11 Sally May sm sm ccccc cc c cc ccc 12 Tom Cat tc tc null null null
Basically I need to choose the most current "max(res_id)" occurance for John Doe above to get only one row out of his three rows. Then I need to get all the other unique rows from table 1.
I hope that is clear. I was considering a cursor. Any ideas??
Is using cursor the only way to do update in this case. I'm updating TableA.ID with TableB.New_id where TableA.ID = TableB.ID. TableA has 2.5 million records and TableB has 500,000 records. Doing it this way bring the system down to it's knees, and is taking forever. Any suggestion are welcome.
declare mrn_cur cursor for select dealer_ident, kealer_id from dealer for read only
declare @result int declare @temp_ident int declare @temp_id int declare @temp_var int
open mrn_cur fetch mrn_cur into @temp_ident, @temp_id
while (@@fetch_status = 0) begin begin transaction update label set dealer_id = @temp_ident where dealer_id = @temp_id commit tran fetch mrn_cur into @temp_ident, @temp_id end close mrn_cur deallocate mrn_cur go
I am writing an application for a training facility. I have three tables in particular that I'm concerned with.
Here they are with the relevent keys 1. Registrations - contains a customerid and a classid 2. Sessions - contains a classid (multiple sessions can exist for a class) 3. Attendence - contains a session and a customerid.
Whenever I insert a session record for a class, I want to automatically create a corresponding record in the attendence table for every student in the class . My only thought is to create an insert trigger on the session table than creates creates a cursor containing the customerid for every student registered in the class. Then I can walk through the cursor and insert an Attendence record for each student.
I really don't want to use a cursor if I can help it, but I can't think of a way to write an single INSERT statement to put into my trigger. Is there a way to do this without using a cursor?
