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• Adding one subquery makes query a little slower, adding another makes it way slower

  - by Jason Swett

  This is fast: select ba.name, penamt.value penamt, #address_line4.value address_line4 from account a join customer c on a.customer_id = c.id join branch br on a.branch_id = br.id join bank ba on br.bank_id = ba.id join account_address aa on aa.account_id = a.id join address ad on aa.address_id = ad.id join state s on ad.state_id = s.id join import i on a.import_id = i.id join import_bundle ib on i.import_bundle_id = ib.id join (select * from unused where heading_label = 'PENAMT') penamt ON penamt.account_id = a.id #join (select * from unused where heading_label = 'Address Line 4') address_line4 ON address_line4.account_id = a.id where i.active=1 And this is fast: select ba.name, #penamt.value penamt, address_line4.value address_line4 from account a join customer c on a.customer_id = c.id join branch br on a.branch_id = br.id join bank ba on br.bank_id = ba.id join account_address aa on aa.account_id = a.id join address ad on aa.address_id = ad.id join state s on ad.state_id = s.id join import i on a.import_id = i.id join import_bundle ib on i.import_bundle_id = ib.id #join (select * from unused where heading_label = 'PENAMT') penamt ON penamt.account_id = a.id join (select * from unused where heading_label = 'Address Line 4') address_line4 ON address_line4.account_id = a.id where i.active=1 But this is slow: select ba.name, penamt.value penamt, address_line4.value address_line4 from account a join customer c on a.customer_id = c.id join branch br on a.branch_id = br.id join bank ba on br.bank_id = ba.id join account_address aa on aa.account_id = a.id join address ad on aa.address_id = ad.id join state s on ad.state_id = s.id join import i on a.import_id = i.id join import_bundle ib on i.import_bundle_id = ib.id join (select * from unused where heading_label = 'PENAMT') penamt ON penamt.account_id = a.id join (select * from unused where heading_label = 'Address Line 4') address_line4 ON address_line4.account_id = a.id where i.active=1 Why is it fast when I include just one of the two subqueries but slow when I include both? I would think it should be twice as slow when I include both, but it takes a really long time. On on MySQL.

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• How to edit datagridview using SqlCeDataAdapter?

  - by DanSogaard

  I've a frmEdit with datagridview that's bouned to this: string sqlqry1 = "select p_Name from Items where p_Id=" + p_Id; using (SqlCeDataAdapter a = new SqlCeDataAdapter(sqlqry1, conn)) { DataTable dt1 = new DataTable(); a.Fill(dt1); dataGridView1.DataSource = dt1; } How to edit cells and save them back to the db?, tried using this: using (SqlCeDataAdapter a = new SqlCeDataAdapter(sqlqry1, conn)) { DataTable dt1 = new DataTable(); a.Fill(dt1); dataGridView1.DataSource = dt1; a.Update(dt1); } Nothing. Is there anyway?.

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• How do I make a grouped select box grouped by a column for a given model in Formtastic for Rails?

  - by jklina

  In my Rails project I'm using Formtastic to manage my forms. I have a model, Tags, with a column, "group". The group column is just a simple hardcoded way to organize my tags. I will post my Tag model class so you can see how it's organized class Tag < ActiveRecord::Base class Group BRAND = 1 SEASON = 2 OCCASION = 3 CONDITION = 4 SUBCATEGORY = 5 end has_many :taggings, :dependent => :destroy has_many :plaggs, :through => :taggings has_many :monitorings, :as => :monitorizable validates_presence_of :name, :group validates_uniqueness_of :name, :case_sensitive => false def self.brands(options = {}) self.all({ :conditions => { :group => Group::BRAND } }.merge(options)) end def self.seasons(options = {}) self.all({ :conditions => { :group => Group::SEASON } }.merge(options)) end def self.occasions(options = {}) self.all({ :conditions => { :group => Group::OCCASION } }.merge(options)) end def self.conditions(options = {}) self.all({ :conditions => { :group => Group::CONDITION } }.merge(options)) end def self.subcategories(options = {}) self.all({ :conditions => { :group => Group::SUBCATEGORY } }.merge(options)) end def self.non_brands(options = {}) self.all({ :conditions => [ "`group` != ? AND `group` != ?", Tag::Group::SUBCATEGORY, Tag::Group::BRAND] }.merge(options)) end end My goal is to use Formtastic to provide a grouped multiselect box, grouped by the column, "group" with the tags that are returned from the non_brands method. I have tried the following: = f.input :tags, :required => false, :as => :select, :input_html => { :multiple => true }, :collection => tags, :selected => sel_tags, :group_by => :group, :prompt => false But I receive the following error: (undefined method `klass' for nil:NilClass) Any ideas where I'm going wrong? Thanks for looking :]

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• Sorting a GridView

  - by Markus

  Hi, I have a question regarding GridView windows forms control. As a datasource, I am using a DataTable object. When the grid view is sorted, the DataTable's row indices are not sorted. In this way, when accessing the DataTable using indices from GridView, I get the unexpected rows. How can this situation be handled?

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• What is the return type for a anonymous linq query select? What is the best way to send this data ba

  - by punkouter

  This is a basic question. I have the basic SL4/RIA project set up and I want to create a new method in the domain service and return some data from it. I am unsure the proper easiest way to do this.. Should I wrap it up in a ToList()? I am unclear how to handle this anonymous type that was create.. what is the easiest way to return this data? public IQueryable<ApplicationLog> GetApplicationLogsGrouped() { var x = from c in ObjectContext.ApplicationLogs let dt = c.LogDate group c by new { y = dt.Value.Year, m = dt.Value.Month, d = dt.Value.Day } into mygroup select new { aaa = mygroup.Key, ProductCount = mygroup.Count() }; return x; // return this.ObjectContext.ApplicationLogs.Where(r => r.ApplicationID < 50); } Cannot implicitly convert type 'System.Linq.IQueryable<AnonymousType#1>' to 'System.Linq.IQueryable<CapRep4.Web.ApplicationLog>'. An explicit conversion exists (are you missing a cast?) 58 20 CapRep4.Web

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• return the variable used for using inside the using C#

  - by di3go

  Hello, I am returning the variable I am creating in a using statement inside the using statement (sounds funny): public DataTable foo () { using (DataTable properties = new DataTable()) { // do something return properties; } } Will this Dispose the properties variable?? After doing this am still getting this Warning: Warning 34 CA2000 : Microsoft.Reliability : In method 'test.test', call System.IDisposable.Dispose on object 'properties' before all references to it are out of scope. Any Ideas? Thanks

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• Grabbing rows from MySql where current date is in between start date and end date (Check if current date lies between start date and end date)

  - by Jordan Parker

  I'm trying to select from the database to get the "campaigns" that dates fall into the month. So far i've been successful in grabbing rows that starts or ends inside the current month. What I need to do now is select rows that start in one month and ends a few months down the line ( EG: It's the 3rd month in the year, and there's a "campaign" that runs from the 1st month until the 5th. other example There is a "campaign" that runs from 2012 until 2013 ) I'm hoping there is some way to select via MySql all rows in which a capaign may run. If not should I grab all data in the database and only show the ones that run via the current month. I have already made a function that displays all the days inbetween each date inside an array, which is called "dateRange". I've also created another which shows how many days the campaign runs for called "runTime". Select all (Obviously) $result = mysql_query("SELECT * FROM campaign"); Select Starting This Month $result = mysql_query("SELECT * FROM campaign WHERE YEAR( START ) = YEAR( CURDATE( ) ) AND MONTH( START ) = MONTH( CURDATE( ) )"); Select Ending This Month $result = mysql_query("SELECT * FROM campaign WHERE YEAR( END ) = YEAR( CURDATE( ) ) AND MONTH( END ) = MONTH( CURDATE( ) ) LIMIT 0 , 30"); Code sample while($row = mysql_fetch_array($result)) { $dateArray = dateRange($row['start'], $row['end']); echo "<h3>" . $row['campname'] . "</h3> Start " . $row['start'] . "<br /> End " . $row['end']; echo runTime($row['start'], $row['end']); print_r($dateArray); } In regards to the dates, MySql database only holds start date and end date of the campaign.

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• mysql: select ... where id = any value. is it possible?

  - by Syom

  look at this table please table |id| |name| |order| i must get the rows, where name = something and order = somevalue so i write select `id` from `table` where `name` = 'something' and `order` = 'somevalue' but depend on php logic, sometimes i need to get all rows, where name = somethimg, independently of order value. i don't want to change the query structure, because in practise there are many number of fields, and possible count of queries will became very big. so i want to save the structure of query, and when i need to select just by name, i want to write something like this select `id` from `table` where `name` = 'something' and `order` = any value is it possible? maybe the question is incomprehensible, at least i tried;) sorry for bad english thanks

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• How can i return dataset perfectly from sql?

  - by Phsika

  i try to write a winform application: i dislike below codes: DataTable dt = new DataTable(); dt.Load(dr); ds = new DataSet(); ds.Tables.Add(dt); Above part of codes looks unsufficient.How can i best loading dataset? public class LoadDataset { public DataSet GetAllData(string sp) { return LoadSQL(sp); } private DataSet LoadSQL(string sp) { SqlConnection con = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"].ToString()); SqlCommand cmd = new SqlCommand(sp, con); DataSet ds; try { con.Open(); cmd.CommandType = CommandType.StoredProcedure; SqlDataReader dr = cmd.ExecuteReader(); DataTable dt = new DataTable(); dt.Load(dr); ds = new DataSet(); ds.Tables.Add(dt); return ds; } finally { con.Dispose(); cmd.Dispose(); } } }

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• Using mod-rewrite to conditionally select existing file in a subdirectory based on Host header?

  - by Kevin Hakanson

  I'm working through a problem where I want to select a different static content file based on the incoming Host header. The simple example is a mapping from URLs to files like this: www.example.com/images/logo.gif - \images\logo.gif skin2.example.com/images/logo.gif - \images\skin2\logo.gif skin3.example.com/images/logo.gif - \images\skin3logo.gif I have this working with the following RewriteRules, but I don't like how I have to repeat myself so much. Each host has the same set of rules, and each RewriteCond and RewriteRule has the same path. I'd like to use the RewriteMap, but I don't know how to use it to map the %{HTTP_HOST} to the path. <VirtualHost *:80> DocumentRoot "C:/Program Files/Apache Software Foundation/Apache2.2/htdocs" ServerName www.example.com ServerAlias skin2.example.com ServerAlias skin3.example.com RewriteEngine On RewriteCond %{HTTP_HOST} skin2.example.com RewriteCond %{DOCUMENT_ROOT}$1/skin2/$2 -f RewriteRule ^(.*)/(.*) $1/skin2/$2 [L] RewriteCond %{HTTP_HOST} skin3.example.com RewriteCond %{DOCUMENT_ROOT}$1/skin3/$2 -f RewriteRule ^(.*)/(.*) $1/skin3/$2 [L] </VirtualHost> The concept behind the rules is if the same filename exists in a subdirectory for that host, use it instead of the direct targeted file. This uses host based subdirectories at the lowest level, and not a top level subdirectory to separate content.

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• Trigger for insert table

  - by shanks

  I have sql server 2005 and need to create trigger for insert query. I have Table naemd as "Log" with column named as UserID,UserName,LogDate,LogTime and want to transfer data into other table named as "DataTable" with same column name. I have created trigger GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TRIGGER [dbo].[Transfer] on [dbo].[Log] AFTER INSERT AS BEGIN insert into DataTable (UserID,UserName,LogDate,LogTime) SELECT UserID,UserName,LogDate,LogTime FROM Log where UserID not in(select UserID from DataTable) END New Data is updated on daily basis in "Log" table and so i want to transfer new data from Log table to DataTable with trigger.Execution time is very high and so no output .

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• How to convert DateTime to shortdatetime in C#??

  - by Abhishek Rao

  I have a column in my datatable which is of DateTime Type. I only want the DatePart, hence when I use the ToShortDateTimeString it converts to short date but of string type. Hence when i reassign the string to the column of the datatable it again appends 12:00:00 to it. I cannot change the column type in my datatable. Is there any way to convert DateTime to ShortDateTime directly without converting to string?????

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• web service filling gridview awfully slow, as is paging/sorting

  - by nat

  Hi I am making a page which calls a web service to fill a gridview this is returning alot of data, and is horribly slow. i ran the svcutil.exe on the wsdl page and it generated me the class and config so i have a load of strongly typed objects coming back from each request to the many service functions. i am then using LINQ to loop around the objects grabbing the necessary information as i go, but for each row in the grid i need to loop around an object, and grab another list of objects (from the same request) and loop around each of them.. 1 to many parent object child one.. all of this then gets dropped into a custom datatable a row at a time.. hope that makes sense.... im not sure there is any way to speed up the initial load. but surely i should be able to page/sort alot faster than it is doing. as at the moment, it appears to be taking as long to page/sort as it is to load initially. i thought if when i first loaded i put the datasource of the grid in the session, that i could whip it out of the session to deal with paging/sorting and the like. basically it is doing the below protected void Page_Load(object sender, EventArgs e) { //init the datatable //grab the filter vars (if there are any) WebServiceObj WS = WSClient.Method(args); //fill the datatable (around and around we go) foreach (ParentObject po in WS.ReturnedObj) { var COs = from ChildObject c in WS.AnotherReturnedObj where c.whatever.equals(...) ...etc foreach(ChildObject c in COs){ myDataTable.Rows.Add(tlo.this, tlo.that, c.thisthing, c.thatthing, etc......); } } grdListing.DataSource = myDataTable; Session["dt"] = myDataTable; grdListing.DataBind(); } protected void Listing_PageIndexChanging(object sender, GridViewPageEventArgs e) { grdListing.PageIndex = e.NewPageIndex; grdListing.DataSource = Session["dt"] as DataTable; grdListing.DataBind(); } protected void Listing_Sorting(object sender, GridViewSortEventArgs e) { DataTable dt = Session["dt"] as DataTable; DataView dv = new DataView(dt); string sortDirection = " ASC"; if (e.SortDirection == SortDirection.Descending) sortDirection = " DESC"; dv.Sort = e.SortExpression + sortDirection; grdListing.DataSource = dv.ToTable(); grdListing.DataBind(); } am i doing this totally wrongly? or is the slowness just coming from the amount of data being bound in/return from the Web Service.. there are maybe 15 columns(ish) and a whole load of rows.. with more being added to the data the webservice is querying from all the time any suggestions / tips happily received thanks

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• Removing "Using temporary; Using filesort" from this MySQL select+join+group by query

  - by claytontstanley

  I have the following query: select t.Chunk as LeftChunk, t.ChunkHash as LeftChunkHash, q.Chunk as RightChunk, q.ChunkHash as RightChunkHash, count(t.ChunkHash) as ChunkCount from chunksubset as t join chunksubset as q on t.ID = q.ID group by LeftChunkHash, RightChunkHash And the following explain table: id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE subsets ref PRIMARY,IDIndex,SubsetIndex SubsetIndex 767 const 522014 "Using where; Using temporary; Using filesort" 1 SIMPLE subsets eq_ref PRIMARY,IDIndex,SubsetIndex PRIMARY 771 sotero.subsets.Id,const 1 "Using where; Using index" 1 SIMPLE c ref IDIndex IDIndex 4 sotero.subsets.Id 12 "Using where" 1 SIMPLE c ref IDIndex IDIndex 4 sotero.subsets.Id 12 note the "using temporary; using filesort". When this query is run, I quickly run out of RAM (presumably b/c of the temp table), and then the HDD kicks in, and the query slows to a halt. I thought it might be an index issue, so I started adding a few that sort of made sense: Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment chunks 0 PRIMARY 1 ChunkId A 17796190 NULL NULL BTREE chunks 1 ChunkHashIndex 1 ChunkHash A 243783 NULL NULL BTREE chunks 1 IDIndex 1 Id A 1483015 NULL NULL BTREE chunks 1 ChunkIndex 1 Chunk A 243783 NULL NULL BTREE chunks 1 ChunkTypeIndex 1 ChunkType A 2 NULL NULL BTREE chunks 1 chunkHashByChunkIDIndex 1 ChunkHash A 243783 NULL NULL BTREE chunks 1 chunkHashByChunkIDIndex 2 ChunkId A 17796190 NULL NULL BTREE chunks 1 chunkHashByChunkTypeIndex 1 ChunkHash A 243783 NULL NULL BTREE chunks 1 chunkHashByChunkTypeIndex 2 ChunkType A 261708 NULL NULL BTREE chunks 1 chunkHashByIDIndex 1 ChunkHash A 243783 NULL NULL BTREE chunks 1 chunkHashByIDIndex 2 Id A 17796190 NULL NULL BTREE But still using the temporary table. The db engine is MyISAM. How can I get rid of the using temporary; using filesort in this query? Just changing to InnoDB w/o explaining the underlying cause is not a particularly satisfying answer. Besides, if the solution is to just add the proper index, then that's much easier than migrating to another db engine.

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• Generated sql from LINQ to SQL

  - by Muhammad Kashif Nadeem

  Following code ProductPricesDataContext db = new ProductPricesDataContext(); var products = from p in db.Products where p.ProductFields.Count > 3 select new { ProductIDD = p.ProductId, ProductName = p.ProductName.Contains("hotel"), NumbeOfProd = p.ProductFields.Count, totalFields = p.ProductFields.Sum(o => o.FieldId + o.FieldId) }; Generated follwing sql SELECT [t0].[ProductId] AS [ProductIDD], (CASE WHEN [t0].[ProductName] LIKE '%hotel%' THEN 1 WHEN NOT ([t0].[ProductName] LIKE '%hotel%') THEN 0 ELSE NULL END) AS [ProductName], ( SELECT COUNT(*) FROM [dbo].[ProductField] AS [t2] WHERE [t2].[ProductId] = [t0].[ProductId] ) AS [NumbeOfProd], ( SELECT SUM([t3].[FieldId] + [t3].[FieldId]) FROM [dbo].[ProductField] AS [t3] WHERE [t3].[ProductId] = [t0].[ProductId]) AS [totalFields] FROM [dbo].[Product] AS [t0] WHERE (( SELECT COUNT(*) FROM [dbo].[ProductField] AS [t1] WHERE [t1].[ProductId] = [t0].[ProductId] )) > 3 Why is this CASE statement for ProductName and because of this instead of ProductName i am just getting 0 in my result set. It should generate sql like following, (where ProductName like '%hotel%' SELECT [t0].[ProductId] AS [ProductIDD], [ProductName], ( SELECT COUNT(*) FROM [dbo].[ProductField] AS [t2] WHERE [t2].[ProductId] = [t0].[ProductId] ) AS [NumbeOfProd], ( SELECT SUM([t3].[FieldId] + [t3].[FieldId]) FROM [dbo].[ProductField] AS [t3] WHERE [t3].[ProductId] = [t0].[ProductId]) AS [totalFields] FROM [dbo].[Product] AS [t0] WHERE (( SELECT COUNT(*) FROM [dbo].[ProductField] AS [t1] WHERE [t1].[ProductId] = [t0].[ProductId] )) > 3 AND t0.ProductName like '%hotel%' Thanks.

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• Sorting in dataview not happening properly(C#3.0)

  - by Newbie

  I have the following DataTable dt = new DataTable(); dt.Columns.Add("col1", typeof(string)); dt.Columns.Add("col2", typeof(string)); dt.Rows.Add("1", "r1"); dt.Rows.Add("1", "r2"); dt.Rows.Add("1", "r3"); dt.Rows.Add("1", "r4"); dt.Rows.Add("2", "r1"); dt.Rows.Add("2", "r2"); dt.Rows.Add("2", "r3"); dt.Rows.Add("2", "r4"); dt.Rows.Add("3", "r1"); dt.Rows.Add("3", "r2"); dt.Rows.Add("3", "r3"); dt.Rows.Add("3", "r4"); dt.Rows.Add("1", "r1"); dt.Rows.Add("1", "r2"); DataView dv = new DataView(dt); dv.Sort = "col1"; DataTable dResult = dv.Table; I am trying to sort the datatable with the help of dataview so that the result will be 1 r1 1 r2 ... 2 r1 2 r2 ... 3 r1 3 r2 ...... Means all 1's first followed by 2's and 3r's Even I tried with dt.DefaultView.Sort = "col1"; but no luck. But it is not happening. Only the result i am able to view in dv.Sort and not the datatable (dResult) I am using C#3.0. Please help Thanks

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• Update table without using cursor and on date

  - by Muhammad Kashif Nadeem

  Please copy and run following script DECLARE @Customers TABLE (CustomerId INT) DECLARE @Orders TABLE ( OrderId INT, CustomerId INT, OrderDate DATETIME ) DECLARE @Calls TABLE (CallId INT, CallTime DATETIME, CallToId INT, OrderId INT) ----------------------------------------------------------------- INSERT INTO @Customers SELECT 1 INSERT INTO @Customers SELECT 2 ----------------------------------------------------------------- INSERT INTO @Orders SELECT 10, 1, DATEADD(d, -20, GETDATE()) INSERT INTO @Orders SELECT 11, 1, DATEADD(d, -10, GETDATE()) ----------------------------------------------------------------- INSERT INTO @Calls SELECT 101, DATEADD(d, -19, GETDATE()), 1, NULL INSERT INTO @Calls SELECT 102, DATEADD(d, -17, GETDATE()), 1, NULL INSERT INTO @Calls SELECT 103, DATEADD(d, -9, GETDATE()), 1, NULL INSERT INTO @Calls SELECT 104, DATEADD(d, -6, GETDATE()), 1, NULL INSERT INTO @Calls SELECT 105, DATEADD(d, -5, GETDATE()), 1, NULL ----------------------------------------------------------------- I want to update @Calls table and need following results. I am using the following query UPDATE @Calls SET OrderId = ( CASE WHEN (s.CallTime > e.OrderDate) THEN e.OrderId END ) FROM @Calls s INNER JOIN @Orders e ON s.CallToId = e.CustomerId and the result of my query is not what I need. Requirement: As you can see there are two orders. One is on 2010-12-12 and one is on 2010-12-22. I want to update @Calls table with relevant OrderId with respect to CallTime. In short If subsequent Orders are added, and there are further calls then we assume that a new call is associated with the most recent Order Note: This is sample data so this is not the case that I always have two Orders. There might be 10+ Orders and 100+ calls. Note2 I could not find good title for this question. Please change it if you think of any better. Thanks.

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• How can I use SQL to select duplicate records, along with counts of related items?

  - by mipadi

  I know the title of this question is a bit confusing, so bear with me. :) I have a (MySQL) database with a Person record. A Person also has a slug field. Unfortunately, slug fields are not unique. There are a number of duplicate records, i.e., the records have different IDs but the same first name, last name, and slug. A Person may also have 0 or more associated articles, blog entries, and podcast episodes. If that's confusing, here's a diagram of the structure: I would like to produce a list of records that match this criteria: duplicate records (i.e., same slug field) for people who also have at least 1 article, blog entry, or podcast episode. I have a SQL query that will list all records with the same slug fields: SELECT id, first_name, last_name, slug, COUNT(slug) AS person_records FROM people_person GROUP BY slug HAVING (COUNT(slug) > 1) ORDER BY last_name, first_name, id; But this includes records for people that may not have at least 1 article, blog entry, or podcast. Can I tweak this to fit the second criteria?

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• help! Linq query

  - by menon

  I am getting error msg on the word Records - Type or namespace could not be found. Please help debugging it, what is missing? if (ProjDDL1.SelectedItem.Value != "--") results = CustomSearch<Records>(results, s => s.Business == ProjDDL1.SelectedItem.Value); Method CustomSearch: private DataTable CustomSearch<TKEY>(DataTable dt, Func<Records, bool> selector) { DataTable results = (dt.AsEnumerable().Where(selector).CopyToDataTable()); return results; }

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• The question about the basics of LINQ to SQL working

  - by Alex

  I just started learning LINQ to SQL, and so far I'm impressed with the easy of use and good performance. I used to think that when doing LINQ queries like from Customer in DB.Customers where Customer.Age > 30 select Customer Get all customers from the database ("SELECT * FROM Customers"), move them to the Customers array and then make a search in that Array using .NET methods. This is very inefficient, what if there are hundreds of thousands of customers in the database? Making such big SELECT queries would kill the web application. Now after experiencing how actually fast LINQ to SQL is, I start to suspect that when doing that query I just wrote, LINQ somehow converts it to a SQL Query string SELECT * FROM Customers WHERE Age > 30 And only when necessary it will run the query. So my question is: am I right? And when is the query actually run? The reason why I'm asking is not only because I want to understand how it works in order to build good optimized applications, but because I came across the following problem. I have 2 tables, one of them is Books, the other has information on how many books were sold on certain days. My goal is to select books that had at least 50 sales/day in past 10 days. It's done with this simple query: from Book in DB.Books where (from Sale in DB.Sales where Sale.SalesAmount >= 50 and Sale.DateOfSale >= DateTime.Now.AddDays(-10) select Sale.BookID).Contains(Book.ID) select Book The point is, I have to use the checking part in several queries and I decided to create an array with IDs of all popular books: var popularBooksIDs = from Sale in DB.Sales where Sale.SalesAmount >= 50 and Sale.DateOfSale >= DateTime.Now.AddDays(-10) select Sale.BookID; BUT when I try to do the query now: from Book in DB.Books where popularBooksIDs.Contains(Book.ID) select Book It doesn't work! That's why I think that we can't use thins kinds of shortcuts in LINQ to SQL queries, like we can't use them in real SQL. We have to create straightforward queries, am I right?

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• How to deal with a flaw in System.Data.DataTableExtensions.CopyToDataTable()

  - by andy

  Hey guys, so I've come across something which is perhaps a flaw in the Extension method .CopyToDataTable. This method is used by Importing (in VB.NET) System.Data.DataTableExtensions and then calling the method against an IEnumerable. You would do this if you want to filter a Datatable using LINQ, and then restore the DataTable at the end. i.e: Imports System.Data.DataRowExtensions Imports System.Data.DataTableExtensions Public Class SomeClass Private Shared Function GetData() As DataTable Dim Data As DataTable Data = LegacyADO.NETDBCall Data = Data.AsEnumerable.Where(Function(dr) dr.Field(Of Integer)("SomeField") = 5).CopyToDataTable() Return Data End Function End Class In the example above, the "WHERE" filtering might return no results. If this happens CopyToDataTable throws an exception because there are no DataRows. Why? The correct behavior should be to return a DataTable with Rows.Count = 0. Can anyone think of a clean workaround to this, in such a way that whoever calls CopyToDataTable doesn't have to be aware of this issue? System.Data.DataTableExtensions is a Static Class so I can't override the behavior....any ideas? Have I missed something? cheers UPDATE: I have submitted this as an issue to Connect. I would still like some suggestions, but if you agree with me, you could vote up the issue at Connect via the link above cheers

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• jQuery Ajax loads URL multiple times, how do I unbind/rebind properly?

  - by gmoz22

  I load a SELECT element via Ajax (list of brands), get its selected value (brand id) and load another SELECT via another Ajax URL (list of templates for currently selected brand). Here's my code: $(document).ready( function() { // DO NOT cache Ajax calls $.ajaxSetup ({ cache: false }); // loader var ajax_load = "Loading..."; // Brands List URL var loadBrandUrl = "getBrandsList.php"; // Templates List URL var loadTemplateUrl = "getTemplatesList.php"; $("#brandslistSelect").html(ajax_load).load(loadBrandUrl) .ajaxComplete(function(){ // Brands select loaded /* Load Templates SELECT the first time since no .change() has happened */ var selectedBrand = $("#brandslistSelect option:selected").attr("value"); // get the value console.log(selectedBrand); // Log selected brand to console // get Templates select, commented for now since it does an infinite loop // $("#templateslistSelect").html(ajax_load).load(loadTemplateUrl, { BrandId: selectedBrand } ); /* End initial load template */ /* On interaction with the Brands SELECT */ $("#brandslistSelect").change(function () { // on interaction with select selectedBrand = $("#brandslistSelect option:selected").attr("value"); // get the value // get Templates SELECT $("#templateslistSelect").html(ajax_load).load(loadTemplateUrl, { BrandId: selectedBrand } ) }); /* End interaction with the Brands SELECT */ }); }); It returns selectedBrand in the console 3 times : selectedBrand = undefined selectedBrand = undefined selectedBrand = 101 Now, if I uncomment the following line, same output as above but it also loads the templates URL indefinitely : // $("#templateslistSelect").html(ajax_load).load(loadTemplateUrl, { BrandId: selectedBrand } ); Any idea how I could modify this code to make it work as intended? Thanks for your help stackOverflow community!

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• please check my MYSQL query & give me advice?

  - by Suba

  select s.s_nric as NRIC,s.s_name as NAME,s.s_psle_eng as PSLE_ENG,s.s_psle_math as PSLE_MATHS,s.s_psle_aggr as PSLE_AGGR, (SELECT re.re_mark FROM si_results re WHERE re.re_code like 'FEEN%' AND re.re_year='2008' AND re.re_semester='2' AND re.re_nric=s.s_nric ) as English_2008, (SELECT re.re_mark FROM si_results re WHERE re.re_code like 'FEMA%' AND re.re_year='2008' AND re.re_semester='2' AND re.re_nric=s.s_nric ) Maths_2008, (SELECT re.re_mark FROM si_results re WHERE re.re_code like 'FEEN%' AND re.re_year='2009' AND re.re_semester='2' AND re.re_nric=s.s_nric ) as English_2009, (SELECT re.re_mark FROM si_results re WHERE re.re_code like 'FEMA%' AND re.re_year='2009' AND re.re_semester='2' AND re.re_nric=s.s_nric ) Maths_2009 ,isc.isc_g_gpa as ISC_GPA from si_student_data as s LEFT JOIN si_isc_gpa as isc ON isc.isc_g_nric=s.s_nric where 1=1 AND s.s_admission_year='2008' GROUP BY s.s_nric ORDER BY s.s_gender,s.s_name asc This is my query. please check my sub query this is my sub query (SELECT re.re_mark FROM si_results re WHERE re.re_code like 'FEEN%' AND re.re_year='2008' AND re.re_semester='2' AND re.re_nric=s.s_nric ) as English_2008, (SELECT re.re_mark FROM si_results re WHERE re.re_code like 'FEMA%' AND re.re_year='2008' AND re.re_semester='2' AND re.re_nric=s.s_nric ) Maths_2008, (SELECT re.re_mark FROM si_results re WHERE re.re_code like 'FEEN%' AND re.re_year='2009' AND re.re_semester='2' AND re.re_nric=s.s_nric ) as English_2009, (SELECT re.re_mark FROM si_results re WHERE re.re_code like 'FEMA%' AND re.re_year='2009' AND re.re_semester='2' AND re.re_nric=s.s_nric ) Maths_2009 When I execute my query, server take long time to execute. So how to make simple? please advice me. Thanks.

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• SELECT product from subclass: How many queries do I need?

  - by Stefano

  I am building a database similar to the one described here where I have products of different type, each type with its own attributes. I report a short version for convenience product_type ============ product_type_id INT product_type_name VARCHAR product ======= product_id INT product_name VARCHAR product_type_id INT -> Foreign key to product_type.product_type_id ... (common attributes to all product) magazine ======== magazine_id INT title VARCHAR product_id INT -> Foreign key to product.product_id ... (magazine-specific attributes) web_site ======== web_site_id INT name VARCHAR product_id INT -> Foreign key to product.product_id ... (web-site specific attributes) This way I do not need to make a huge table with a column for each attribute of different product types (most of which will then be NULL) How do I SELECT a product by product.product_id and see all its attributes? Do I have to make a query first to know what type of product I am dealing with and then, through some logic, make another query to JOIN the right tables? Or is there a way to join everything together? (if, when I retrieve the information about a product_id there are a lot of NULL, it would be fine at this point). Thank you

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• jQuery select image in div if image parent does't have a certain class.

  - by Alex

  Wordpress wraps images with captions in a div with a class of .wp-caption. I'm looking for a way to select images that don't have this div so I can wrap them in different div. (to keep a consistent border around all the images) <div class="blog-post-content"> <div id="attachment_220" class="wp-caption alignleft" style="width: 310px"> <a href="/somewhere/"><img class="size-medium wp-image-220" src="/path/to/image" alt="" width="300" height="280" /></a> <p class="wp-caption-text">Caption Text</p> </div> <p>This is the body of the post</p> </div> To test my selector, I'm just trying to add a green border. I can handle the .wrap() once the selector is working. The most promising of my attempts is: $('.blog-post-content img').parent('div:not(".wp-caption")').css('border', '2px solid green'); ... but no luck.

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