Search Results

Search found 27530 results on 1102 pages for 'sql truncate'.

Page 340/1102 | < Previous Page | 336 337 338 339 340 341 342 343 344 345 346 347  | Next Page >

  • B-trees, databases, sequential inputs, and speed.

    - by IanC
    I know from experience that b-trees have awful performance when data is added to them sequentially (regardless of the direction). However, when data is added randomly, best performance is obtained. This is easy to demonstrate with the likes of an RB-Tree. Sequential writes cause a maximum number of tree balances to be performed. I know very few databases use binary trees, but rather used n-order balanced trees. I logically assume they suffer a similar fate to binary trees when it comes to sequential inputs. This sparked my curiosity. If this is so, then one could deduce that writing sequential IDs (such as in IDENTITY(1,1)) would cause multiple re-balances of the tree to occur. I have seen many posts argue against GUIDs as "these will cause random writes". I never use GUIDs, but it struck me that this "bad" point was in fact a good point. So I decided to test it. Here is my code: SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[T1]( [ID] [int] NOT NULL CONSTRAINT [T1_1] PRIMARY KEY CLUSTERED ([ID] ASC) ) GO CREATE TABLE [dbo].[T2]( [ID] [uniqueidentifier] NOT NULL CONSTRAINT [T2_1] PRIMARY KEY CLUSTERED ([ID] ASC) ) GO declare @i int, @t1 datetime, @t2 datetime, @t3 datetime, @c char(300) set @t1 = GETDATE() set @i = 1 while @i < 2000 begin insert into T2 values (NEWID(), @c) set @i = @i + 1 end set @t2 = GETDATE() WAITFOR delay '0:0:10' set @t3 = GETDATE() set @i = 1 while @i < 2000 begin insert into T1 values (@i, @c) set @i = @i + 1 end select DATEDIFF(ms, @t1, @t2) AS [Int], DATEDIFF(ms, @t3, getdate()) AS [GUID] drop table T1 drop table T2 Note that I am not subtracting any time for the creation of the GUID nor for the considerably extra size of the row. The results on my machine were as follows: Int: 17,340 ms GUID: 6,746 ms This means that in this test, random inserts of 16 bytes was almost 3 times faster than sequential inserts of 4 bytes. Would anyone like to comment on this? Ps. I get that this isn't a question. It's an invite to discussion, and that is relevant to learning optimum programming.

    Read the article

  • JOIN in SQL with one-to-many relationship

    - by Kristopher Ives
    I'm making a tool to track calls to house/senate reps, and I have 2 tables of importance here: reps rep_id rep_name # and more info comments rep_id status # enum about result of contact comment I want to query for all reps joining the most recent associated comments and in some cases joining comments of a specific status, but there might not be any comments associated with that rep yet. THANKS!

    Read the article

  • using PIVOT to sql server.

    - by NoviceToDotNet
    This is the abstract idea which i want to do by my first select of first line, i am presenting here, but i am unable to do that correct. here category[0], category[2]..etc representing the category columns values...i know this kind of syntax not work, but i want to do something like this. SELECT category[0], category[1], category[2], category[3], category[4], category[5] FROM( select Row_number() OVER(ORDER BY (SELECT 1)) AS 'Serial Number', EP.FirstName,Ep.LastName, Ep.SignUpID, [dbo].[GetBookingRoleName](ES.UserId,EP.BookingRole) as RoleName, (select top 1 convert(varchar(10),eventDate,103)from [3rdi_EventDates] where EventId=@ItemId) as EventDate, (CASE [dbo].[GetBookingRoleName](ES.UserId,EP.BookingRole) WHEN 'Employee - Marketing' THEN 'DC' WHEN 'Employee - Accounting' THEN 'DC' WHEN 'Coaches' THEN 'DC' WHEN 'Student Client' THEN 'ST' WHEN 'Guest Doctor' THEN 'GDC' ---....more categories here, i just removed a few END) as Category from [3rdi_EventParticipants] as EP inner join [3rdi_EventSignup] as ES on EP.SignUpId = ES.SignUpId WHERE EP.EventId = @ItemId AND EP.PlaceStatus IN (0,3,4,8) and userid in( select distinct userid from userroles where roleid not in(19,20,21,22) and roleid not in(1,2, 25, 44)) (My Below Query) PIVOT(sum(First_Name+Last_Name)) FOR Category (category[0], category[1], category[2], category[3], category[4], category[5]) Group by (SignUpID)

    Read the article

  • oracle sql query to list all the dates of previous month

    - by Suresh S
    Guys i have a requirement to list all the dates of the previous month like below 20101201 20101202 20101203 20101204 20101205 .. .. .. .. .. .. .. .. 20101231 kindly let me know if any better way to do than this query. select TO_CHAR(TRUNC(SYSDATE,'MM')-1,'YYYYMMDD')-(level-1) as EACH_DATE from dual A connect by level < (TO_NUMBER(TO_CHAR(TRUNC(SYSDATE,'MM')-1,'DD'))+1) Also please let me know the problem with this query it says "missing right parenthesis" SELECT /*+ PARALLEL (A,8) */ /*+ DRIVING_STATE */ TO_CHAR(TRUNC(TRUNC(SYSDATE,'MM')-1,'MM'),'MONYYYY') "MONTH", TYPE AS "TRAFF", COLUMN, A_COUN AS "A_COUNT",COST FROM DATA_P B WHERE EXISTS ( select TO_NUMBER(TO_CHAR(TRUNC(SYSDATE,'MM')-1,'YYYYMMDD')-(level-1)) EACH_DATE from dual A connect by level < TO_NUMBER(TO_CHAR(TRUNC(SYSDATE,'MM')-1,'DD')+1) WHERE A.EACH_DATE = B.DATE order by EACH_DATE ASC )

    Read the article

  • How to select product that have the maximum price of each category?

    - by kimleng
    The below is my table that has the item such as: ProductId ProductName Category Price 1 Tiger Beer $12.00 2 ABC Beer $13.99 3 Anchor Beer $9.00 4 Apolo Wine $10.88 5 Randonal Wine $18.90 6 Wisky Wine $30.19 7 Coca Beverage $2.00 8 Sting Beverage $5.00 9 Spy Beverage $4.00 10 Angkor Beer $12.88 And I suppose that I have only three category in this table (I can have a lot of category in this table). And I want to show the maximum product's price of each category in this table.

    Read the article

  • getting sql records

    - by droidus
    when i run this code, it returns the topic fine... $query = mysql_query("SELECT topic FROM question WHERE id = '$id'"); if(mysql_num_rows($query) > 0) { $row = mysql_fetch_array($query) or die(mysql_error()); $topic = $row['topic']; } but when I change it to this, it doesn't run at all. why is this happening? $query = mysql_query("SELECT topic, lock FROM question WHERE id = '$id'"); if(mysql_num_rows($query) > 0) { $row = mysql_fetch_array($query) or die(mysql_error()); $topic = $row['topic']; $lockedThread = $row['lock']; echo "here: " . $lockedThread; }

    Read the article

  • Sql Trigger Trouble

    - by SImon
    Hey guys i cant get this trigger to work, ive worked on it for an hour or so and cant see to figure out where im going wrong, any help would be appreciated CREATE OR REPLACE TRIGGER allergy BEFORE INSERT ON DECLARE med VARCHAR2(20); BEGIN SELECT v.medication RCD.specify INTO med FROM visit v, relcondetails RCD WHERE :new.medication = v.medication AND RCD.specifiy = 'allergies'; IF med = allergies THEN RAISE_APPLICATION_ERROR(-20000, 'Patient Is alergic to this medication'); END IF; END allergy; When put into oracle ERROR at line 6: ORA-04079: invalid trigger specification

    Read the article

  • Sql Distinct Count of resulting table with no conditionals

    - by AfterImage
    Hello everyone, I want to count the number of accounts from the resulting table generated from this code. This way, I know how many people liked blue at one time. Select Distinct PEOPLE.FullName, PEOPLE.FavColor From PEOPLE Where FavColor='Blue' Lets say this is a history accounting of what people said their favorite color when they were asked so there may be multiple records of the same full name if asked again at a much later time; hence the distinct. The code I used may not be reusable in your answer so feel free to use what you think can work. I am sure I found a possible solution to my problem using declare and if statements but I lost that page... so I am left with no solution. However, I think there is a way to do it without using conditionals which is what I am asking and rather have. Thanks. Edit: My question is: From the code above, is there a way to count the number of accounts in the resulting table?

    Read the article

  • SQL Server Reporting Services Bar Chart

    - by Avitus
    I am trying to create horizontal bar chart to look like a pill chart. I would like to take a either a stacked bar chart or a 100% stacked bar chart and put rounded ends onto this chart. I would only be using 1 row within the chart. One idea I had was just putting rounded images on either end of the chart to accomplish this but I'm not sure that this will give the smooth feel of a single pill. Does anyone have a good suggestion? I am not tied to the idea of using a chart object. But I would prefer to stay away from third party components that need to be purchased.

    Read the article

  • SQL 2008 HierarchyID - Select X descendants down

    - by NTulip
    How can I query a table which has a column of data type HIERARCHYID and get a list of descendants X levels deep under an employee? Here is the current structure: CREATE TABLE [dbo].[Employees]( [NodeId] [hierarchyid] NOT NULL, [EmployeeId] [int] IDENTITY(1,1) NOT NULL, [FirstName] [varchar](120) NULL, [MiddleInitial] [varchar](1) NULL, [LastName] [varchar](120) NULL, [DepartmentId] [int] NULL, [Title] [varchar](120) NULL, [PhoneNumber] [varchar](20) NULL, [IM] [varchar](120) NULL, [Photo] [varbinary](max) NULL, [Bio] [varchar](400) NULL, [Active] [bit] NULL, [ManagerId] [int] NULL )

    Read the article

  • SQL Syntax for Complex Scenario (Deals)

    - by Yisman
    hello everyone i have a complex query to be written but cannot figure it out here are my tables Sales --one row for each sale made in the system SaleProducts --one row for each line in the invoice (similar to OrderDetails in NW) Deals --a list of possible deals/offers that a sale may be entitled to DealProducts --a list of quantities of products that must be purchased in order to get a deal now im trying to make a query which will tell me for each sale which deals he may get the relevant fields are: Sales: SaleID (PK) SaleProducts: SaleID (FK), ProductID (FK) Deals: DealID (PK) DealProducts: DealID(FK), ProductID(FK), Mandatories (int) for required qty i believe that i should be able to use some sort of cross join or outer join, but it aint working here is one sample (of about 30 things i tried) SELECT DealProducts.DealID, DealProducts.ProductID, DealProducts.Mandatories, viwSaleProductCount.SaleID, viwSaleProductCount.ProductCount FROM DealProducts LEFT OUTER JOIN viwSaleProductCount ON DealProducts.ProductID = viwSaleProductCount.ProductID GROUP BY DealProducts.DealID, DealProducts.ProductID, DealProducts.Mandatories, viwSaleProductCount.SaleID, viwSaleProductCount.ProductCount the problem is that it doesnt show any product deals that r not fullfiled (probably because of the productid join). i need that also sales that dont have the requiremnets show up, then i can filter out any saleid that exists in this query "where AmountBought thank you for your help

    Read the article

  • SQL Query over three different tables

    - by choise
    i got three tables CATS id name ------------------------------ 1 category1 2 category2 3 category3 4 category4 PRODUCT id name ------------------------------ 1 product1 2 product2 ZW-CAT-PRODUCT id_cats id_product ------------------------------ 1 1 3 1 4 2 now i want to get my products and their categories product1 => category1,category3 product2 => category4 is there a way to get this array (or object or something) with one mysql query? i tried a bit with JOINS, but it seems thats this is not exactly what i need, or? currently i'm using 3 querys (i think thats too much). any suggestions?

    Read the article

  • need help with a simple SQL update statement.

    - by Tony
    There's a field with type of varchar. It actually stores a float point string. Like 2.0 , 12.0 , 34.5 , 67.50 ... What I need is a update statement that remove the ending zeros of fields like 2.0 , 12.0 , change them to their integer representation , that is 2 , 12 ...,and leave 3.45 , 67.50 unchanged . How should I do this ? I am using oracle 10.

    Read the article

  • nested join linq-to-sql queries

    - by ile
    var result = ( from contact in db.Contacts where contact.ContactID == id join referContactID in db.ContactRefferedBies on contact.ContactID equals referContactID.ContactID join referContactName in db.Contacts on contact.ContactID equals referContactID.ContactID orderby contact.ContactID descending select new ContactReferredByView { ContactReferredByID = referContactID.ContactReferredByID, ContactReferredByName = referContactName.FirstName + " " + referContactName.LastName }).Single(); Problem is in this line: join referContactName in db.Contacts on contact.ContactID equals referContactID.ContactID where referContactID.ContactID is called from the above join line. How to nest these two joins? Thanks in advance! Ile

    Read the article

  • Can a Snapshot transaction fail and only partially commit in a TransactionScope?

    - by Travis Brooks
    Greetings I stumbled onto a problem today that seems sort of impossible to me, but its happening...I'm calling some database code in c# that looks something like this: using(var tran = MyDataLayer.Transaction()) { MyDataLayer.ExecSproc(new SprocTheFirst(arg1, arg2)); MyDataLayer.CallSomethingThatEventuallyDoesLinqToSql(arg1, argEtc); tran.Commit(); } I've simplified this a bit for posting, but whats going on is MyDataLayer.Transaction() makes a TransactionScope with the IsolationLevel set to Snapshot and TransactionScopeOption set to Required. This code gets called hundreds of times a day, and almost always works perfectly. However after reviewing some data I discovered there are a handful of records created by "SprocTheFirst" but no corresponding data from "CallSomethingThatEventuallyDoesLinqToSql". The only way that records should exist in the tables I'm looking at is from SprocTheFirst, and its only ever called in this one function, so if its called and succeeded then I would expect CallSomethingThatEventuallyDoesLinqToSql would get called and succeed because its all in the same TransactionScope. Its theoretically possible that some other dev mucked around in the DB, but I don't think they have. We also log all exceptions, and I can find nothing unusual happening around the time that the records from SprocTheFirst were created. So, is it possible that a transaction, or more properly a declarative TransactionScope, with Snapshot isolation level can fail somehow and only partially commit?

    Read the article

  • Application self aware of external database record modifications.

    - by Khou
    How do you make your application aware that a database record was changed or created by an external application rather than the application itself? Do you add a special check sum to the database record or what do you do to stop external changes to the database? (in case it was hacked and the hacker decides to add a new record or change an existing database record)

    Read the article

  • How to work with CTE. There is some error related to anchor.

    - by Shantanu Gupta
    I am creating a hierarchy representaion of a column. But an error occurs Details are Msg 240, Level 16, State 1, Line 1 Types don't match between the anchor and the recursive part in column "DISPLAY" of recursive query "CTE". I know there is some typecasting error. But I dont know how to remove error. Please just dont only sort out my error. I need explanation why this error is coming. When this error occurs. I am trying to sort table on the basis of sort col that i m introducing. I want to add '-' at every level and want to sort accordingly. Please help WITH CTE (PK_CATEGORY_ID, [DESCRIPTION], FK_CATEGORY_ID, DISPLAY, SORT, DEPTH) AS ( SELECT PK_CATEGORY_ID, [DESCRIPTION], FK_CATEGORY_ID, '-' AS DISPLAY, '--' AS SORT, 0 AS DEPTH FROM dbo.L_CATEGORY_TYPE WHERE FK_CATEGORY_ID IS NULL UNION ALL SELECT T.PK_CATEGORY_ID, T.[DESCRIPTION], T.FK_CATEGORY_ID, CAST(DISPLAY+T.[DESCRIPTION] AS VARCHAR(1000)), '--' AS SORT, C.DEPTH +1 FROM dbo.L_CATEGORY_TYPE T JOIN CTE C ON C.PK_CATEGORY_ID = T.FK_CATEGORY_ID --SELECT T.PK_CATEGORY_ID, C.SORT+T.[DESCRIPTION], T.FK_CATEGORY_ID --, CAST('--' + C.SORT AS VARCHAR(1000)) AS SORT, CAST(DEPTH +1 AS INT) AS DEPTH --FROM dbo.L_CATEGORY_TYPE T JOIN CTE C ON C.FK_CATEGORY_ID = T.PK_CATEGORY_ID ) SELECT PK_CATEGORY_ID, [DESCRIPTION], FK_CATEGORY_ID, DISPLAY, SORT, DEPTH FROM CTE ORDER BY SORT

    Read the article

  • SQLServer - Test the result of a stored procedure

    - by Melursus
    In Microsoft SQLServer, it is possible to test the result of a stored procedure to know if the result return rows or nothing ? Example : EXEC _sp_MySp 1, 2, 3 IF @@ROWCOUNT = 0 BEGIN PRINT('Empty') END ELSE BEGIN PRINT(@@ROWCOUNT) END But @@ROWCOUNT always return 0 so maybe is there another way of doing this ?

    Read the article

  • Asp.net Report Viewer - Custom filter parameters

    - by Chris
    Hi all, for a data warehouse project I need to know about some best practices regarding custom report viewer filters/parameters. Usually I use the standard parameter feature for reports, like multiple select boxes, check boxes, text boxes etc.. But for the current project some reports require more complex report parameters. E.g. a user wants to analyze some measures. For that the user needs to set a filter on a specific address. There are over 100.000 address to choose from, so he has to have the ability to search for an address (full text). Since such features cannot be done with the standard parameters, I will have to create custom params within a ASPX page which are then passed to the report viewer control. So my question is: Are there any best practices on how to create custom parameters? Did anyone had similar problems, if so, how did you solve it?

    Read the article

  • Forming triangles from points and relations

    - by SiN
    Hello, I want to generate triangles from points and optional relations between them. Not all points form triangles, but many of them do. In the initial structure, I've got a database with the following tables: Nodes(id, value) Relations(id, nodeA, nodeB, value) Triangles(id, relation1_id, relation2_id, relation3_id) In order to generate triangles from both nodes and relations table, I've used the following query: INSERT INTO Triangles SELECT t1.id, t2.id , t3.id, FROM Relations t1, Relations t2, Relations t3 WHERE t1.id < t2.id AND t3.id > t1.id AND ( t1.nodeA = t2.nodeA AND (t3.nodeA = t1.nodeB AND t3.nodeB = t2.nodeB OR t3.nodeA = t2.nodeB AND t3.nodeB = t1.nodeB) OR t1.nodeA = t2.nodeB AND (t3.nodeA = t1.nodeB AND t3.nodeB = t2.nodeA OR t3.nodeA = t2.nodeA AND t3.nodeB = t1.nodeB) ) It's working perfectly on small sized data. (~< 50 points) In some cases however, I've got around 100 points all related to each other which leads to thousands of relations. So when the expected number of triangles is in the hundreds of thousands, or even in the millions, the query might take several hours. My main problem is not in the select query, while I see it execute in Management Studio, the returned results slow. I received around 2000 rows per minute, which is not acceptable for my case. As a matter of fact, the size of operations is being added up exponentionally and that is terribly affecting the performance. I've tried doing it as a LINQ to object from my code, but the performance was even worse. I've also tried using SqlBulkCopy on a reader from C# on the result, also with no luck. So the question is... Any ideas or workarounds?

    Read the article

  • SQL Querying for Threaded Messages

    - by Harper
    My site has a messaging feature where one user may message another. The messages support threading - a parent message may have any number of children but only one level deep. The messages table looks like this: Messages - Id (PK, Auto-increment int) - UserId (FK, Users.Id) - FromUserId (FK, Users.Id) - ParentMessageId (FK to Messages.Id) - MessageText (varchar 200) I'd like to show messages on a page with each 'parent' message followed by a collapsed view of the children messages. Can I use the GROUP BY clause or similar construct to retrieve parent messages and children messages all in one query? Right now I am retrieving parent messages only, then looping through them and performing another query for each to get all related children messages. I'd like to get messages like this: Parent1 Child1 Child2 Child3 Parent2 Child1 Parent3 Child1 Child2

    Read the article

  • build SQL query string using user input

    - by user175084
    i have to make a string by using the values which the user selects on the webpage suppose i need to display files for multiple machines with differnt search criteria.. i currently use this code: DataTable dt = new DataTable(); SqlConnection connection = new SqlConnection(); connection.ConnectionString = ConfigurationManager.ConnectionStrings["DBConnectionString"].ConnectionString; connection.Open(); SqlCommand sqlCmd = new SqlCommand("SELECT FileID FROM Files WHERE MachineID=@machineID and date= @date", connection); SqlDataAdapter sqlDa = new SqlDataAdapter(sqlCmd); sqlCmd.Parameters.AddWithValue("@machineID", machineID); sqlCmd.Parameters.AddWithValue("@date", date); sqlDa.Fill(dt); now this is fixed query where the user just has one machine and just selects one date... i want to make a query in which the user has multiple search options like type or size if he wants depending on what he selects also if he can select multiple machines.. SELECT FileID FROM Files WHERE (MachineID=@machineID1 or MachineID = @machineID2...) and (date= @date and size=@size and type=@type... ) all of this happens in runtime... other wise i have to create a for loop to put multiple machines one by one... and have multiple queries depending on the case the user selected... this is quiet interesting and i could use some help... thanks

    Read the article

  • Why won't this sql update query work?

    - by Wesley
    I have a table that has 5,000(table1) lines in it. Currently, 3,000 of them are filled up with data. The remaining values are currently null. In a separate table(table2), I have the remaining 2,000 rows of data. I am simply trying to take the values in table2 and put them in table1, but this statement isn't working: Update table1 Set field1 = (Select field1 From table2 Where table1.id = table2.id) Where Exists(Select field1 From table2 Where table1.id = table2.id) It looks like this should be working, but I am getting an error from Base, the db program I am using that just says error Near " ": syntax error...any help?? Thanks!

    Read the article

  • SQL Trigger dont works...

    - by Gabotron
    Is there a way in which a Trigger is not fired? We have this situation: We have a table and there are rows that are been deleted. We need to know who and/or when these row are deleted. We create this trigger: ALTER TRIGGER [dbo].[AUDITdel_nit] ON [dbo].[Client] FOR DELETE AS Insert into AUDIT select 'Delete', getdate(), 'Row Deleted', SYSTEM_USER, host_name(), (select 'ID Client: ' + convert(varchar(12),Id) from deleted), 'Client' ,APP_NAME() We made somte test: deleting rows vis stored procedures and the deleted rows appears in our AUDIT table. But suddenly today we found a row deleted that dont appears in the AUDIT table... Any idea how it can be done?

    Read the article

< Previous Page | 336 337 338 339 340 341 342 343 344 345 346 347  | Next Page >