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• Extreme Optimization Numerical Libraries for .NET – Part 1 of n

  - by JoshReuben

  While many of my colleagues are fascinated in constructing the ultimate ViewModel or ServiceBus, I feel that this kind of plumbing code is re-invented far too many times – at some point in the near future, it will be out of the box standard infra. How many times have you been to a customer site and built a different variation of the same kind of code frameworks? How many times can you abstract Prism or reliable and discoverable WCF communication? As the bar is raised for whats bundled with the framework and more tasks become declarative, automated and configurable, Information Systems will expose a higher level of abstraction, forcing software engineers to focus on more advanced computer science and algorithmic tasks. I've spent the better half of the past decade building skills in .NET and expanding my mathematical horizons by working through the Schaums guides. In this series I am going to examine how these skillsets come together in the implementation provided by ExtremeOptimization. Download the trial version here: http://www.extremeoptimization.com/downloads.aspx Overview The library implements a set of algorithms for: linear algebra, complex numbers, numerical integration and differentiation, solving equations, optimization, random numbers, regression, ANOVA, statistical distributions, hypothesis tests. EONumLib combines three libraries in one - organized in a consistent namespace hierarchy. Mathematics Library - Extreme.Mathematics namespace Vector and Matrix Library - Extreme.Mathematics.LinearAlgebra namespace Statistics Library - Extreme.Statistics namespace System Requirements -.NET framework 4.0  Mathematics Library The classes are organized into the following namespace hierarchy: Extreme.Mathematics – common data types, exception types, and delegates. Extreme.Mathematics.Calculus - numerical integration and differentiation of functions. Extreme.Mathematics.Curves - points, lines and curves, including polynomials and Chebyshev approximations. curve fitting and interpolation. Extreme.Mathematics.Generic - generic arithmetic & linear algebra. Extreme.Mathematics.EquationSolvers - root finding algorithms. Extreme.Mathematics.LinearAlgebra - vectors , matrices , matrix decompositions, solvers for simultaneous linear equations and least squares. Extreme.Mathematics.Optimization – multi-d function optimization + linear programming. Extreme.Mathematics.SignalProcessing - one and two-dimensional discrete Fourier transforms. Extreme.Mathematics.SpecialFunctions

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• MYSQL - Selecting a specific date range to get "current" popular screensavers.

  - by Joe

  Let's say I have a screensaver website. I want to display the CURRENT top 100 screensavers on the front page of the website. What I mean is, "RECENT" top 100 screensavers. What would be an example query to do this? My current one is: SELECT * FROM tbl_screensavers WHERE WEEK(tbl_screensavers.DateAdded) = WEEK('".date("Y-m-d H:i:s",strtotime("-1 week"))."') ORDER BY tbl_screensavers.ViewsCount, tbl_screensavers.DateAdded This will select the most viewed ("tbl_screensavers.ViewsCount") screensavers that were added ("tbl_screensavers.DateAdded") in the last week. However, in some cases there are no screensavers, or less than 100 screensavers, submitted in that week. So, how can I perform a query which would select "RECENT" top 100 screensavers? Hopefully you have an idea of what I'm try to accomplish when I say "RECENT" or "CURRENT" top screensavers. -- aka. the most viewed, recently - not the most viewed, all-time.

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• Require help in Writing Query

  - by harigm

  The following image have been uploaded to show what I am trying to do and what I wanted out of it Can any one help me write the Query to get the results what I want Please check the following SELECT * FROM KPT WHERE PROPERTY_ID IN (SELECT PROPERTY_ID FROM khata_header WHERE DIV_ID = 3 and RECORD_STATUS = 0) and CHALLAN_NO > 42646 The above is the query I have written and I have got the following result set ID CHALLAN_NO PROPERTY_ID SITE_NO TOTAL_AMOUNT ----- ------------- -------------- ------------------- --------------- 1242 42757 3103010141 296 595 1243 63743 3204190257 483 594 1244 63743 3204190257 483 594 1334 43395 3217010223 1088 576 1421 524210 3320050416 (null) (null) 1422 524210 3320050416 (null) (null) 1560 564355 3320021408 (null) (null) 1870 516292 3320040420 (null) (null) 1940 68357 3217100104 139 1153 1941 68357 3217100104 139 1153 2002 56256 3320100733 511 4430 2003 56256 3320100733 511 4430 2004 66488 3217040869 293 3094 2005 66488 3217040869 293 3094 2016 64571 3217040374 (null) (null) 2036 523122 3320020352 (null) (null) 2039 65682 3217040021 273 919 In my resultset, I am getting the PropertyId repeated, since there are multilple entries, How Can I know How many have been repeated What are those Property Id which have repeated more than 2 times. Little Back ground about the tables are PROPERTY_ID is the FK in the KPT PROPERTY_ID is the PK in KH I am writing a subquery to get the Result, so I am stuck I dont know how to get my results Please help

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• Understanding #DAX Query Plans for #powerpivot and #tabular

  - by Marco Russo (SQLBI)

  Alberto Ferrari wrote a very interesting white paper about DAX query plans. We published it on a page where we'll gather articles and tools about DAX query plans: http://www.sqlbi.com/topics/query-plans/I reviewed the paper and this is the result of many months of study - we know that we just scratched the surface of this topic, also because we still don't have enough information about internal behavior of many of the operators contained in a query plan. However, by reading the paper you will start reading a query plan and you will understand how it works the optimization found by Chris Webb one month ago to the events-in-progress scenario. The white paper also contains a more optimized query (10 time faster), even if the performance depends on data distribution and the best choice really depends on the data you have. Now you should be curious enough to read the paper until the end, because the more optimized query is the last example in the paper!

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• Beginners guide to developing optimization software

  - by Florenc

  I am novice in "serious" programming i.e. applications that deal with real-life applications and software projects that go beyond school assignments. My interests include optimization, operations research, algorithms and lately i discovered how much I do like software design/development/engineering. I have already developed some simple desktop applications for some "famous" problems like TSP using heuristc approaches, a VRP solver (in progress) and so on. While developing this kind of software I actually used basic concepts taught at school such as object-orientation analysis and design. But, I found these courses rather elementary and quite boring (for my expectations). So I decided to go a little further and start developing "real" software (and this is where I realized how important and interesting software engineering/design is.) Now, here's my issue: I can not find a "study guide" for developing software of this kind. Currently, there are numerous resources out there (books, websites, tutorials) in designing and developing complex IS, web applications, smartphone apps but I can't find a book for example entitled "optimization software development". Definetly, someone could claim that "design patterns apply to software in general" but that's not my point. My point is that I could simply use my imagination for "simple" implementations, but what happens, when my imagination can not go further? In other words I'm looking for a guide/path to bridge the gap between: Mathematics-Algorithm Design-Software Engineering-Optimization-Software development

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• In SQL Server what is most efficient way to compare records to other records for duplicates with in

  - by Glenn

  We have an SQL Server that gets daily imports of data files from clients. This data is interrelated and we are always scrubbing it and having to look for suspect duplicate records between these files. Finding and tagging suspect records can get pretty complicated. We use logic that requires some field values to be the same, allows some field values to differ, and allows a range to be specified for how different certain field values can be. The only way we've found to do it is by using a cursor based process, and it places a heavy burden on the database. So I wanted to ask if there's a more efficient way to do this. I've heard it said that there's almost always a more efficient way to replace cursors with clever JOINS. But I have to admit I'm having a lot of trouble with this one. For a concrete example suppose we have 1 table, an "orders" table, with the following 6 fields. order_id, customer_id product_id, quantity, sale_date, price We want to look through the records to find suspect duplicates on the following example criteria. These get increasingly harder. 1. Records that have the same product_id, sale_date, and quantity but different customer_id's should be marked as suspect duplicates for review. 2. Records that have the same customer_id, product_id, quantity and have sale_dates within five days of each other should be marked as suspect duplicates for review 3. Records that have the same customer_id, product_id, but different quantities within 20 units, and sales dates within five days of each other should be considered suspect. Is it possible to satisfy each one of these criteria with a single SQL Query that uses JOINS? Is this the most efficient way to do this?

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• Insert new row with data computed from other rows

  - by Tyler McHenry

  Suppose I have a MySQL table called MyTable, that looks like this: +----+------+-------+ | Id | Type | Value | +----+------+-------+ | 0 | A | 1 | | 0 | B | 1 | | 1 | A | 2 | | 1 | B | 3 | | 2 | A | 5 | | 2 | B | 8 | +----+------+-------+ And, for each Id, I want to insert a new row with type C whose Value is the sum of the type A and B values for the rows of the same Id. The primary key on this table is (Id, Type), so there's no question of duplication of Id,Type pairs. I can create the rows I want with this query: SELECT MyTable_A.Id AS Id, 'C' AS Type, (A_Val + B_Val) AS Value FROM (SELECT Id, Value AS A_Val FROM MyTable WHERE Type='A') AS MyTable_A JOIN (SELECT Id, Value AS B_Val FROM MyTable WHERE Type='B') AS MyTable_B ON MyTable_A.Id = MyTable_B.Id Giving: +----+------+-------+ | Id | Type | Value | +----+------+-------+ | 0 | C | 2 | | 1 | C | 5 | | 2 | C | 13 | +----+------+-------+ But the question is: How do I use this result to insert the generated type-C rows into MyTable? Is there a relatively simple way to do this with a query, or do I need to write a stored procedure? And if the latter, guidance would be helpful, as I'm not too well versed in them.

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• SQL Server 05, which is optimal, LIKE %<term>% or CONTAINS() for searching large column

  - by Spud1

  I've got a function written by another developer which I am trying to modify for a slightly different use. It is used by a SP to check if a certain phrase exists in a text document stored in the DB, and returns 1 if the value is found or 0 if its not. This is the query: SELECT @mres=1 from documents where id=@DocumentID and contains(text, @search_term) The document contains mostly XML, and the search_term is a GUID formatted as an nvarchar(40). This seems to run quite slowly to me (taking 5-6 seconds to execute this part of the process), but in the same script file there is also this version of the above, commented out. SELECT @mres=1 from documents where id=@DocumentID and textlike '%' + @search_term + '%' This version runs MUCH quicker, taking 4ms compared to 15ms for the first example. So, my question is why use the first over the second? I assume this developer (who is no longer working with me) had a good reason, but at the moment I am struggling to find it.. Is it possibly something to do with the full text indexing? (this is a dev DB I am working with, so the production version may have better indexing..) I am not that clued up on FTI really so not quite sure at the moment. Thoughts/ideas?

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• Optional parameters with named query in Hibernate?

  - by Ickster

  Is there any way to specify optional parameters (such as when search parameters are provided from a form and not all parameters are required) in a named query when using Hibernate? I'm using a native SQL query, but the question is probably applicable to named HQL queries as well. I'm pretty sure the answer to this is 'no', but I haven't find the definitive answer in the documentation yet.

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• hierachical query to return final row

  - by jeff

  I have a hierarchical query that doesn't return an expected row (employee badge = 444). TABLE: hr_data badge fname supervisor_badge 111 Jeff 222 222 Joe 333 333 John 444 444 Tom 444 SQL: SELECT CONNECT_BY_ISCYCLE As IC, badge, fname, supervisor_badge FROM hr_data START WITH badge = '111' CONNECT BY NOCYCLE badge = PRIOR supervisor_badge What is Returned: IC badge fname supervisor_badge 0 111 Jeff 222 0 222 Joe 333 1 333 John 444 What is Expected: IC badge fname supervisor_badge 0 111 Jeff 222 0 222 Joe 333 **0** 333 John 444 **1** 444 Tom 444 How can I get this query to return the employee Tom and then stop?

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• Using Treelist Values to Query a Sitecore Item

  - by kirk.burleson

  I have an item named All Recipes that contains recipes named R1, R2, and R3. I have another item named My Recipes that has a treelist field named Recipes and it contains selected values R2 and R3 from the All Recipes item. The query I'm trying to write is for the Items field of an RSS Feed. What is the query syntax to show the items in All Recipes that appear in the Recipes field of My Recipes?

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• fluent nhibernate named-query without using hbm file for the map

  - by user57555

  I am needing to create named-query, and use it with one of the maps, that i currently have defined as a fluent map. is it possible to continue using the fluent map, and be able to create the named-query dynamically in code? or, is switching to a hbm map the only option?

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• Problemwit sql query

  - by phenevo

  Hi, I've got query: INSERT INTO [Tasks] ([LoginName] ,[Type] ,[Filter] ,[Dictionary] ,[Description]) Select N'Anonymous',4,'SomeTable.targetcode in (select Code from cities where countrycode in ('TN')) and SomeTable.SomeValue in ('13','15')',3,N'Cities from tunis' Union All ... [Dictionary] is a part of query that i need to function on my server. I get: Incorrect syntax near ')) and SomeTable.SomeValue in (13,15)'.

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• MySQL query from subquery not working

  - by James Goodwin

  I am trying to return a number based on the count of results from a table and to avoid having to count the results twice in the IF statement I am using a subquery. However I get a syntax error when trying to run the query, the subquery I have tested by itself runs fine. Any ideas what is wrong with the query? The syntax looks correct to me SELECT IF(daily_count>8000,0,IF(daily_count>6000,1,2)) FROM ( SELECT count(*) as daily_count FROM orders201003 WHERE DATE_FORMAT(date_sub(curdate(), INTERVAL 1 DAY),"%d-%m-%y") = DATE_FORMAT(reqDate,"%d-%m-%y") ) q

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• Using Hibernate to do a query involving two tables

  - by Nathan Spears

  I'm inexperienced with sql in general, so using Hibernate is like looking for an answer before I know exactly what the question is. Please feel free to correct any misunderstandings I have. I am on a project where I have to use Hibernate. Most of what I am doing is pretty basic and I could copy and modify. Now I would like to do something different and I'm not sure how configuration and syntax need to come together. Let's say I have two tables. Table A has two (relevant) columns, user GUID and manager GUID. Obviously managers can have more than one user under them, so queries on manager can return more than one row. Additionally, a manager can be managing the same user on multiple projects, so the same user can be returned multiple times for the same manager query. Table B has two columns, user GUID and user full name. One-to-one mapping there. I want to do a query on manager GUID from Table A, group them by unique User GUID (so the same User isn't in the results twice), then return those users' full names from Table B. I could do this in sql without too much trouble but I want to use Hibernate so I don't have to parse the sql results by hand. That's one of the points of using Hibernate, isn't it? Right now I have Hibernate mappings that map each column in Table A to a field (well the get/set methods I guess) in a DAO object that I wrote just to hold that Table's data. I could also use the Hibernate DAOs I have to access each table separately and do each of the things I mentioned above in separate steps, but that would be less efficient (I assume) that doing one query. I wrote a Service object to hold the data that gets returned from the query (my example is simplified - I'm going to keep some other data from Table A and get multiple columns from Table B) but I'm at a loss for how to write a DAO that can do the join, or use the DAOs I have to do the join. FYI, here is a sample of my hibernate config file (simplified to match my example): <hibernate-mapping package="com.my.dao"> <class name="TableA" table="table_a"> <id name="pkIndex" column="pk_index" /> <property name="userGuid" column="user_guid" /> <property name="managerGuid" column="manager_guid" /> </class> </hibernate-mapping> So then I have a DAOImplementation class that does queries and returns lists like public List<TableA> findByHQL(String hql, Map<String, String> params) etc. I'm not sure how "best practice" that is either.

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• Convert SQL query to Ruby help

  - by Verloren

  Hey all, I need to query my database table to find which employee has the most support tickets related to them. I can do this just fine using this MySQL query: SELECT employee_id, COUNT(id) AS number_of_tickets FROM tickets GROUP BY employee_id ORDER BY number_of_tickets DESC LIMIT 1; How would write this in Ruby-on-Rails? Thanks very much for your assistance. I use Ruby version 1.8.6, Rails version 2.2.2 and MySQL Server version 5.0.

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• Issues with Rails 3.1 API with Query String to Create action on Mac OSX Mountain Lion

  - by hjaved

  Hi I've been stuck on this problem for a while and would appreciate your help. I'm writing an API to allow an external source like a Browser Query String or a smartphone to enter some model User info in a form and hit the User create action to write the data to the db. Please tell me what I'm doing wrong with the code below. I've also observed that if I have code like @user = User.new(params[:user]), that this approach only works when a user enters their data within the form. And that if I have code such as @user = User.new( name: params[:name], location: params[:location], password = params[:password], email: params[:email]), that this code ONLY works for a Query string entry, but NOT both Query string AND regular form submission. Why is that and how can I write the code above in the Users Controller Create action, so that it takes care of both situations? URL used: localhost:3000/users/create?name=John&&[email protected]&&password=secret&&location=SanFrancisco&date=06122012 The date is of type string but it doesn't show up in the database. Why? Everything else does. UsersController.rb def create @user = User.new(params[:user]) if @user.save session[:uid] = @user.id redirect_to thanks_path, notice: "Welcome #{@user.name}!" else redirect_to root_path end end New User Form: <%=u.text_field :name, placeholder: "Name"%><br> <%=u.text_field :email, placeholder: "Email"%><br> <%=u.password_field :password, placeholder: "Password"%><br> <%=u.text_field :location, placeholder: "City"%><br> <%=u.text_field :date, placeholder: "Date"%><br> <%if params[:partner_id]%> <%=u.hidden_field :partner_id, value: params[:partner_id]%> <%end%> <button class="btn btn-large btn-primary">Enter</button> I also tried to create a separate method called remotecreate for User creation for something other than a regular web form. I entered remotecreate in the Query string but it didn't work. def remotecreate @user = User.create(name: params[:name], email: params[:email], password: params[:password], location: params[:location], date: params[:date]) if @user.save session[:uid] = @user.id redirect_to thanks_path, notice: "Welcome #{@user.name}" else redirect_to root_path end end Thanks!

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• Any way to speed up this hierarchical query?

  - by RenderIn

  I've got a serious performance problem with a hierarchical query that I can't seem to fix. I am modeling several organization charts in my database, each representing a virtual organization within our company. For example, we have several temporary committees that are created from time to time and there may be a Committee Organizer role at the top of this virtual hierarchy, with several people assigned to the Committee Member role beneath the organizer. Some of our virtual organizations have many levels and several branches at each level. I have a single table in which I represent all the role assignments. i.e. a ROLE_ID column and a PARENT_ROLE_ID column which is a foreign key to the ROLE_ID column. For each assignment we also store as a column the location in the company where this person has the assignment. For example, the Committee Organizer would have a company-level/ CEO assignment, while the committee members would have department-level assignments such as ACCOUNTING, MARKETING, etc. So to model the organizer/member relationship for two individuals we would have: ROLE_ID = 4 PARENT_ROLE_ID = NULL EMPLOYEE_NUMBER = 213423 COMPANY_LOCATION = CEO ROLE_ID = 5 PARENT_ROLE_ID = 4 EMPLOYEE_NUMBER = 838221 COMPANY_LOCATION = ACCOUNTING Here's where things get tricky. I have an application that every person in the organization can log in to. When they log in they should be able to view all the virtual organizations in our company. e.g. the committee members should be able to see the committee organizer and vice-versa. However, only the committee organizer should be able to edit the committee members. The difficulty is in determining whether an individual (who can have multiple role assignments) has edit access for each other assignment. While this seems simple in the example, consider a virtual organization in which we have President at the top, 5 departments directly beneath him, 2 subdepartments below each department. We only want people in the Accounting department to be able to edit individuals in the subdepartments belonging to the Accounting department. They should not have edit access to anybody in the Marketing department or its subdepartments. To determine edit access when a user views a virtual organization in our company I run a query that executes two inline views: A) Hierarchically query for all assignments in this virtual organization and using SYS_CONNECT_BY_PATH to store the entire path to each user/role/company_location and B) Hierarchically retrieve all the assignments the individual logged in has and using the SYS_CONNECT_BY_PATH to store the entire path to each of these assignments. The result of the query is all the records from A) plus a boolean determined by joining with B) which flags whether the logged in user has edit access for each record. Indexes don't seem to be helping... it simply appears that there is too much processing going on to separate all the records and then determine edit access. One issue is that I can't store the SYS_CONNECT_BY_PATH and index it... determining whether an individual record has edit access consists of comparing if: test_record_sys_path LIKE individual_record_sys_path || '%' Is a materialized view the answer?

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• join query in mysql cursor

  - by parag

  As the title describes all we can declare cursor like this DECLARE cur1 CURSOR FOR SELECT id,data FROM test.t1; Can we use join query instead off simple query?

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• How to update multiple rows with one single query

  - by xRobot

  I use Postgresql + PHP. Say I have this table: Books ( id, title, year ) and this array of titles in PHP: $titles = array ("bible","kafka","Book of Eli"); now I want update all rows where the title is in the $titles array above. So I need a query like this: UPDATE books SET year = '2001-11-11' WHERE title is in $titles; Is is possible with one single query ? Or do I need to use FOR loop ?

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• Explicit disable MySQL query cache in some parts of program

  - by jack

  In a Django project, some cronjob programs are mainly used for administrative or analysis purposes, e.g. generating site usage stats, rotating user activities log, etc. We probably do not hope MySQL to cache queries in those programs to save memory usage and improve query cache efficiency. Is it possible to turn off MySQL query cache explicitly in those programs while keep it enabled for other parts including all views.py?

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• Selecting from 2 tables in a single query

  - by duder

  I have a table that I'm querying for value 43 in the second field and I return the value of the third field SELECT t1_field3 FROM table1 WHERE t1_field2=43 this returns 19, 39,73 t1_id t1_field2 t1_field3 ----- --------- --------- 1 43 19//// 2 43 39//// 3 43 73//// 4 73 43 5 13 40 Then I separately query a second table for additional information SELECT * FROM table2 WHERE t2_id=t1_field3 t2_id t2_field2 t2_field3 ----- --------- --------- 19 value19.2 value19.3 39 value39.2 value39.3 73 value73.2 value73.3 Is there a way I could combine both table1 and table2 in the same query?

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• Can I use EXISTS keyword in sql query for assignment of result

  - by Shantanu Gupta

  Can I assign a value with EXISTS in the query. Currently it is giving me error Incorrect syntax near '='. But when I uses this query only it runs as expected. IF EXISTS (SELECT @PK_LOGIN_ID=PK_LOGIN_ID FROM dbo.M_LOGIN WHERE LOGIN_NAME=@LOGIN_NAME AND PASSWORD=@PASSWORD AND FK_ROLE_ID=@FK_ROLE_ID) RETURN @PK_LOGIN_ID ELSE RETURN 0

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• What's wrong with this SQL query?

  - by ThinkingInBits

  I have two tables: photographs, and photograph_tags. Photograph_tags contains a column called photograph_id (id in photographs). You can have many tags for one photograph. I have a photograph row related to three tags: boy, stream, and water. However, running the following query returns 0 rows SELECT p.* FROM photographs p, photograph_tags c WHERE c.photograph_id = p.id AND (c.value IN ('dog', 'water', 'stream')) GROUP BY p.id HAVING COUNT( p.id )=3 Is something wrong with this query?

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• Linq-To-Sql equivalent for this sql query...

  - by Pandiya Chendur

  I thus far used concatenated Id string like 1,2,3 and updated in my table using this query... if exists( select ClientId from Clients where ClientId IN (SELECT i.items FROM dbo.Splitfn(@Id,',') AS i)) begin update Clients set IsDeleted=1 where ClientId IN (SELECT i.items FROM dbo.Splitfn(@Id,',') AS i) select 'deleted' as message end What is the linq-to-sql equivalent for the above query? Any suggestion...

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