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  • An INSERT conditioned on COUNT

    - by Anders Feder
    How can I construct a MySQL INSERT query that only executes if the number of rows satisfying some condition already in the table is less than 20, and fails otherwise? That is, if the table has 18 rows satisfying the condition, then the INSERT should proceed. If the table has 23 rows satisfying the condition, then the INSERT should fail. For atomicity, I need to express this in a single query, so two requests can not INSERT at the same time, each in the 'belief' that only 19 rows satisfy the condition. Thank you.

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  • Entity-attribute-value model using codeigniter / php

    - by John Stewart
    SO I am trying to create a way to structure my database to be able customize forms. I looked into EAV pattern and here is my db structure: Table form - form_id - form_name - form_added_on - form_modified_at Table: form_fields - field_id - form_id - field_type (TEXT, RADIO etc..) - field_default_value - field_required Table: form_data - data_id - field_id - form_id - field_value so now I can store any custom form into the database and if I want to get the values for an individual form I can simply join it by "form_id" .. the problem: I want to be able to search through all the forms for a specific field value. How can I do that with EAV model? Also, I thought about just storing the custom data as a serialized (JSON) object but then I am not sure how can I query that data. Please note that I am using Codeigniter with MYSQL. So if conversation can use Codeigniter libraries if needed.

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  • C# Expression Tree Simple Arithmetic

    - by Richard Adnams
    Hello, I've been trying to figure out how to achieve some simple maths using the Expression class. What I'm trying to do is this (1 + 10 * 15) When I try to do this via Expression.Add and Expression.Constant but the result I get is this ((1 + 10) * 15) Which is not right as it evaluates the 1 + 10 first instead of 10 * 15. Is there a way to combine Expression.Add/Multiply etc.. without it creating the brackets? I assume there is but I just can't find where or how! The test code I have is this var v1 = Expression.Constant(1, typeof(int)); var v2 = Expression.Constant(10, typeof(int)); var v3 = Expression.Constant(15, typeof(int)); var a1 = Expression.Add(v1, v2); var m2 = Expression.Multiply(a1, v3); Thanks for your time, Richard.

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  • Determine Click-thru Percentage With PHP

    - by Lea
    Hi all, I am currently working on a small sponsorship application(PHP/MySql) for my personal blog, and am almost finish, but I am stuck on how to calculate the click-thru rate of my sponsors campaigns. I was always terrible with working out percentages, so any practical help would be appreciated. The data is stored in the DB as simple numbers.. So as expected, when a page refreshes, or a sponsors ad is clicked, the data updates with an incrementation of 1. So using these values...say $clicks and $impressions, how would I determine the click-thru rate? What would be the sum I would use to calculate? An example function would really be appreciated. Kind Regards, Lea

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  • Hard to append a table with many records into another without generating duplicates

    - by Bill Mudry
    I may seem to be a bit wordy at first but for the hope it will be easier for all of you to understand what I am doing in the first place. I have an uncommon but enjoyable activity of collecting as many species of wood from around the world as I can (over 2,900 so far). Ok, that is the real world. Meanwhile I have spent over 8 years compiling over 5.8 meg of text data on all the woods of the world. That got so large that learning some basic PHP and MySQL was most welcome so I could build a new database driven home for all this research. I am still slow at it but getting there. The original premise was to find evidence of as many species of woods in the world I can. The more names identified, the more successful the project. I have named the project TAXA for ease of conversation (short for Taxonomy). You are most welcome to take a look at what I have so far at www.prowebcanada.com/taxa. It is 95% dynamically driven. So far I am reporting about 6,500 botanical wood names and, as said above, the more I can report, the more successful is the project. I have a file of all the woods in the second largest wood collection in the world, the Tervuren wood collection in the Netherlands with over 11,300 wood names even after cleaning out all duplicates. That is almost twice the number I am reporting now so porting all the new wood names from Tervuren to the 'species' table where I keep the reported data would be a major desirable advancement in the project. At one point I was able to add all the Tervuren records to the species table but over 3,000 duplicates also formed. They were not in the Tervuren file in the first place but represent the same wood names common to both files. It is common sense that there would be woods common to both that when merged would create new duplicates. At one point and with the help of others from another forum, I may very well have finally got the proper SQL statement. When I ran it, though, the system said (semi-amusingly at first) ----- that it had gone away! After looking up on the Net what could have have done this, one reason is that the MySQL timeout lapses and probably because of the large size of files I am running. I am running this on a rented account on Godaddy so I cannot go about trying to adjust any config file. For safety, I copied the tervuren.sql file as tervuren_target.sql and the species.sql file as species_master.sql tp use as working files just to make sure I protect the original files from destruction or damage. Later I can name the species_master back to just species.sql once I am happy all worked well. The species file has about 18 columns in it but only 5 columns match the columns in the Tervuren file (name for name and collation also). The rest of the columns are just along for the ride, so to speak. The common key in both is the 'species_name" columns in both. I am not sure it is at all proper to call one a primary key and the other a foreign key since there really is no relational connection to them. One is just more data for the other and can disappear after, never to be referred to the working code in the application. I have been very surprised and flabbergasted on how hard it can be to append records from one large table into another (with same column names plus others) without generating NEW duplicates in the first place. Watch out thinking that a SELECT DISTINCT statement may do the job because absolutely NO records in the species table must get destroyed in the process and there is no way (well, that I know of) to tell the 'DISTINCT" command this. Yes, the original 'species' table has duplicates in it even before all this but, trust me ---- they have to be removed the long hard way manually record by record or I will lose precious information. It is more important to just make sure no NEW duplicates form through bringing in new names in the tervuren_target.species_name into species.species_name. I am hoping and thinking that a straight SQL solution should work --- except for that nasty timeout. How do I get past that? Could it mean that I may have to turn to a PHP plus SQL method?? Or ..... would I have to break up the Tervuren files into a few smaller ones and run them independently (hope not....)" So far, what seems should be easy has proven to be unexpectedly tricky. I appreciate any help you can give but start from the assumption that this may be harder to do right than it may seem on the surface. By the way --- I am running a quad 64 bit system with Windows 7, so at least I have some fairly hefty power on the client end. I have a direct ethernet cable feeding a cable connection to the Internet. Once I get an algorithm and code working for this, I also have many other lists to process that could make the 'species' table grow even more. It could be equivalent to (ahem) lighting a rocket under my project (especially compared to do this record by record manually)! This is my first time in this forum, so I do not know how I can receive any replies. Do I have to to come back here periodically or are replies emailed out also? It would be great if you CC'd copies to me at billmudry at rogers.com :-) Much thanks for your patience and help, Bill Mudry Mississauga, Ontario Canada (next to Toronto).

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  • What frameworks to use to bootstrap my first production scala project ?

    - by Jacques René Mesrine
    I am making my first foray into scala for a production app. The app is currently packaged as a war file. My plan is to create a jar file of the scala compiled artifacts and add that into the lib folder for the war file. My enhancement is a mysql-backed app exposed via Jersey & will be integrated with a 3rd party site via HttpClient invocations. I know how to do this via plain java. But when doing it in scala, there are several decision points that I am pussyfooting on. scala 2.7.7 or 2.8 RC ? JDBC via querulous Is this API ready for production ? sbt vs maven. I am comfortable with maven. Is there a scala idiomatic wrapper for HttpClient (or should I use it just like in java) ? I'd love to hear your comments and experiences on starting out with scala. Thanks

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  • Query Problem.Please help

    - by Ritz
    hello all, i want to use this in my application but i m getting an error for GetByLatest().Cast(); Please suggest me a solution IList news = new Trytable().GetByLatest().Cast(); return new RssResult(news, "William Duffy - Glasgow Based ASP.NET Web Developer", "The latest news on ASP.NET, C# and ASP.NET MVC "); Thanks Ritz

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  • Complicated idea - how to create car racing for my RPG game's players

    - by Donator
    So, I want to create car racing for my RPG game's players. Player can create race and choose how many participants can participate in race. After race is being created, other people can join it. When the maximum participants are collected, race begins. My idea, when the last participant joins, then instantly choose the winner (who's car is the best, that person wins), but how can I do it? If I choose to pick the winner after the last participant joins, then I have to put many queries in one page (select data from table, then delete the race, then select players' cars' statistics and pick the winner and then again, using mysql, send message to everyone). But this idea is really not optimal and it will lag cruelly for that last person. Maybe you have any ideas how I can avoid lag and make it more optimal. Thank you very much.

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  • Linq2XML: Get the count of elements where candidate has won2

    - by user287798
    I had an XML Document in the format below <Pronvice_Data> <Pronvice>PronviceA</Pronvice> <Registered_Voters>115852</Registered_Voters> <Sam_Kea>100</Sam_Kea> <Jeje>500</Jeje> <John_Doe>400</John_Doe> </Pronvice_Data> <Pronvice_Data> <Pronvice>PronviceA</Pronvice> <Registered_Voters>25852</Registered_Voters> <Sam_Kea>200</Sam_Kea> <Jeje>100</Jeje> <John_Doe>300</John_Doe> </Pronvice_Data> <Pronvice_Data> <Pronvice>PronviceC</Pronvice> <Registered_Voters>317684</Registered_Voters> <Sam_Kea>1000</Sam_Kea> <Jeje>1200</Jeje> <John_Doe>190</John_Doe> </Pronvice_Data> As suggested by help here,I used the code below to give me this format below C# Code: void Main() { XDocument xmlVectors2 = XDocument.Load(@"C:\\Province_Data.xml"); var elemList= from elem in xmlVectors2.Descendants("Province_Data") where elem.Elements().Count() > 1 select elem; foreach(XElement element in elemList) { XElement elem1= new XElement("Candidates", new XElement(element.Element("Sam_Kea").Name), new XElement(element.Element("Jeje").Name), new XElement(element.Element("John_Doe").Name) ); XElement elem2 = new XElement("Provinces", new XAttribute("Province", (string)element.Element("Province").Value), new XAttribute("Registered_Voters",element.Element("Registered_Voters").Value), new XElement ("Candidate", new XAttribute("Name",element.Element("Sam_Kea").Name), new XAttribute("Votes",element.Element("Sam_Kea").Value) ), new XElement ("Candidate", new XAttribute("Name",element.Element("Jeje").Name), new XAttribute("Votes",element.Element("Jeje").Value) ), new XElement ("Candidate", new XAttribute("Name",element.Element("John_Doe").Name), new XAttribute("Votes",element.Element("John_Doe").Value) )); } } New Format: <root> <Candidates> <Sam_Kea/> <Jeje/> <John_Doe/> </Candidates> <Provinces> <Province name='ProvinceA' Registered_Voters='115852'> <Candidate name='Sam_Kea' votes='100'/> <Candidate name='Jeje' votes='500'/> <Candidate name='John_Doe' votes='400'/> </Province> <Province name='ProvinceB' Registered_Voters='25852'> <Candidate name='Sam_Kea' votes='200'/> <Candidate name='Jeje' votes='100'/> <Candidate name='John_Doe' votes='300'/> </Province> <Province name='ProvinceC' Registered_Voters='317684'> <Candidate name='Sam_Kea' votes='1000'/> <Candidate name='Jeje' votes='1200'/> <Candidate name='John_Doe' votes='190'/> </Province> </Provinces> </root> How can i use the "foreach" in in my code to get the result in this link. http://stackoverflow.com/questions/2396203/get-the-count-of-elements-where-candidate-has-won

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  • Can't return a List from a Compiled Query.

    - by Andrew
    I was speeding up my app by using compiled queries for queries which were getting hit over and over. I tried to implement it like this: Function Select(ByVal fk_id As Integer) As List(SomeEntity) Using db As New DataContext() db.ObjectTrackingEnabled = False Return CompiledSelect(db, fk_id) End Using End Function Shared CompiledSelect As Func(Of DataContext, Integer, List(Of SomeEntity)) = _ CompiledQuery.Compile(Function(db As DataContext, fk_id As Integer) _ (From u In db.SomeEntities _ Where u.SomeLinkedEntity.ID = fk_id _ Select u).ToList()) This did not work and I got this error message: Type : System.ArgumentNullException, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 Message : Value cannot be null. Parameter name: value However, when I changed my compiled query to return IQueryable instead of List like so: Function Select(ByVal fk_id As Integer) As List(SomeEntity) Using db As New DataContext() db.ObjectTrackingEnabled = False Return CompiledSelect(db, fk_id).ToList() End Using End Function Shared CompiledSelect As Func(Of DataContext, Integer, IQueryable(Of SomeEntity)) = _ CompiledQuery.Compile(Function(db As DataContext, fk_id As Integer) _ From u In db.SomeEntities _ Where u.SomeLinkedEntity.ID = fk_id _ Select u) It worked fine. Can anyone shed any light as to why this is? BTW, compiled queries rock! They sped up my app by a factor of 2.

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  • how to join a set of XElements to the values of a struct?

    - by jcollum
    Let's say I have a struct that contains local environments: public struct Environments { public const string Dev = "DEV"; public const string Qa1 = "SQA"; public const string Prod1 = "PROD"; public const string Prod2 = "PROD_SA"; public const string Uat = "UAT"; } And I'd like to pull a set of XElements out of an xml doc, but only those elements that have a key that matches a value in a struct. this.environments =(from e in settings.Element("Settings").Element("Environments") .Elements("Environment") .Where( x => x.HasAttribute("name") ) join f in [struct?] on e.Attribute("name") equals [struct value?]).ToDictionary(...) How would I go about doing this? Do I need reflection to get the values of the constants in the struct?

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  • Change LINQ2SQL property in partial class?

    - by Fermin
    Hi, I have a table in my LINQ2SQL diagram with a column called DayOfWeek in table JourneyBooking. The designer.cs has the definition of this as: [Column(Storage="_DayOfWeek", DbType="TinyInt NOT NULL")] public int DayOfWeek { get { return this._DayOfWeek; } set { if ((this._DayOfWeek != value)) { this.OnDayOfWeekChanging(value); this.SendPropertyChanging(); this._DayOfWeek = value; this.SendPropertyChanged("DayOfWeek"); this.OnDayOfWeekChanged(); } } } I have a partial class for the JourneyBooking class. Is it possible to extend/overwrite the above DayOfWeek property with my own property? The issue I am having is that DayOfWeek is 0-6 in C# but 1-7 in SQL, so I was thinking that I could overwrite the DayOfWeek property to subtract or add 1 depending on whether it was a get or set, is this possible or would I need to re-write all of the above code in my partial class?

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  • Proper way to format date from database using javascript/jquery

    - by Darcy
    Hi all, I am calling my database which contains a datetime datatype. The date looks like this: 2005-05-23 16:06:00.000 I would like to display this in a table when a user selects a certain item from a list. I call my controller action and return Json of all the times and put them in a table. The problem is the date is completely wrong. What is displayed is this: /Date(1255470180000)/ The date that is returned isn't even parsable (which I don't want to do anyway) so I can't even get the data if I wanted to. Any ideas?

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  • Related objects in reportingviewer 10.0.0.0 give #error

    - by Bart-Jan Poirot
    In my VB.net apps i make use of Linq2SQL and Reportviewer with RDLC reports. With Visual Studio 2010 they upgraded this reportviewer component so you can use the newer RDL specification from 2008. Now I've a problem to show related objects. For example assume you provide an order to the datasource of the report and then you can show something like Fields!Customer.Value.Name where Customer is a related entity. I also got the error in my immediate window: *Warning: The Value expression for the textrun ‘Name_1.Paragraphs[0].TextRuns[0]’ contains an error: The specified operation is not valid. (rsRuntimeErrorInExpression)*

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  • Auditing in Entity Framework.

    - by Gabriel Susai
    After going through Entity Framework I have a couple of questions on implementing auditing in Entity Framework. I want to store each column values that is created or updated to a different audit table. Rightnow I am calling SaveChanges(false) to save the records in the DB(still the changes in context is not reset). Then get the added | modified records and loop through the GetObjectStateEntries. But don't know how to get the values of the columns where their values are filled by stored proc. ie, createdate, modifieddate etc. Below is the sample code I am working on it. //Get the changed entires( ie, records) IEnumerable<ObjectStateEntry> changes = context.ObjectStateManager.GetObjectStateEntries(EntityState.Modified); //Iterate each ObjectStateEntry( for each record in the update/modified collection) foreach (ObjectStateEntry entry in changes) { //Iterate the columns in each record and get thier old and new value respectively foreach (var columnName in entry.GetModifiedProperties()) { string oldValue = entry.OriginalValues[columnName].ToString(); string newValue = entry.CurrentValues[columnName].ToString(); //Do Some Auditing by sending entityname, columnname, oldvalue, newvalue } } changes = context.ObjectStateManager.GetObjectStateEntries(EntityState.Added); foreach (ObjectStateEntry entry in changes) { if (entry.IsRelationship) continue; var columnNames = (from p in entry.EntitySet.ElementType.Members select p.Name).ToList(); foreach (var columnName in columnNames) { string newValue = entry.CurrentValues[columnName].ToString(); //Do Some Auditing by sending entityname, columnname, value } }

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  • XElement vs Dcitionary

    - by user135498
    Hi All, I need advice. I have application that imports 10,000 rows containing name & address from a text file into XElements that are subsequently added to a synchronized queue. When the import is complete the app spawns worker threads that process the XElements by deenqueuing them, making a database call, inserting the database output into the request document and inserting the processed document into an output queue. When all requests have been processed the output queue is written to disk as an XML doc. I used XElements for the requests because I needed the flexibility to add fields to the request during processing. i.e. Depending on the job type the app might require that it add phone number, date of birth or email address to a request based on a name/address match against a public record database. My questions is; The XElements seems to use quite a bit of memory and I know there is a lot of parsing as the document makes its way through the processing methods. I’m considering replacing the XElements with a Dictionary object but I’m skeptical the gain will be worth the effort. In essence it will accomplish the same thing. Thoughts?

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  • Grouping with operands question

    - by Filip
    I have a table: mysql> desc kursy_bid; +-----------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------+-------------+------+-----+---------+-------+ | datetime | datetime | NO | PRI | NULL | | | currency | varchar(6) | NO | PRI | NULL | | | value | varchar(10) | YES | | NULL | | +-----------+-------------+------+-----+---------+-------+ 3 rows in set (0.01 sec) I would like to select some rows from a table, grouped by some time interval (can be one day) where I will have the first row and the last row of the group, the max(value) and min(value). I tried: select datetime, (select value order by datetime asc limit 1) open, (select value order by datetime desc limit 1) close, max(value), min(value) from kursy_bid_test where datetime > '2009-09-14 00:00:00' and currency = 'eurpln' group by month(datetime), day(datetime), hour(datetime); but the output is: | open | close | datetime | max(value) | min(value) | +--------+--------+---------------------+------------+------------+ | 1.4581 | 1.4581 | 2009-09-14 00:00:05 | 4.1712 | 1.4581 | | 1.4581 | 1.4581 | 2009-09-14 01:00:01 | 1.4581 | 1.4581 | As you see open and close is the same (but they shouldn't be). What should be the query to do what I want?

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  • can't login to phpmyadmin

    - by user574383
    Hi, i am new at linux but i need phpmyadmin on my centos server. I did this: cd /var/www/html/ (document root of apache) wget http://sourceforge.net/projects/phpmyadmin/path/to/latest/version tar xvfz phpMyAdmin-3.3.9-all-languages.tar.gz mv phpMyAdmin-3.3.9-all-languages phpmyadmin rm phpMyAdmin-3.3.9-all-languages.tar.gz cd phpmyadmin/ cp config.sample.inc.php config.inc.php Ok so then i just got to a webbrowser and go to www.$ip/phpmyadmin and i am presented with a login screen asking for username and password. How can i get these credentials to log in? I'd like to log in as root i guess. But i don't know how to setup a root account and create a password for root using the cli and mysql. Please help? Thanks.

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  • SQL Table Setup Advice

    - by Ozzy
    Hi all. Basically I have an xml feed from an offsite server. The xml feed has one parameter ?value=n now N can only be between 1 and 30 What ever value i pick, there will always be 4000 rows returned from the XML file. My script will call this xml file 30 times for each value once a day. So thats 120000 rows. I will be doing quite complicated queries on these rows. But the main thing is I will always filter by value first so SELECT * WHERE value = 'N' etc. That will ALWAYS be used. Now is it better to have one table where all 120k rows are stored? or 30 tables were 4k rows are stored? EDIT: the SQL database in question will be MySQL

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  • Lexing partial SQL in C#

    - by Chris T
    I'd need to parse partial SQL queries (it's for a SQL injection auditing tool). For example '1' AND 1=1-- Should break down into tokens like [0] => [SQL_STRING, '1'] [1] => [SQL_AND] [2] => [SQL_INT, 1] [3] => [SQL_AND] [4] => [SQL_INT, 1] [5] => [SQL_COMMENT] [6] => [SQL_QUERY_END] Are their any at least lexers for SQL that I base mine off of or any good tools like bison for C# (though I'd rather not write my own grammar as I need to support most if not all the grammar of MySQL 5)

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  • Returning partial address matches and mismatch position using L2S or SQL

    - by peter3
    I need to implement a method that takes an address split up into individual parts and returns any matching items from an address table. If no matches are found, I want to be able to return a value indicating where it failed. Each input param has a corresponding field in the table. The signature would look something like this: List<Address> MatchAddress(string zipCode, string streetName, string houseNumber, string houseLetter, string floor, string appartmentNo, out int mismatchPosition) { // return matching addresses // if none found, return the position where it stopped matching // zipCode is position 0, appartmentNo is position 5 // // an empty param value indicates "don't check" } I know I can construct the method such that I start with all the parameters, execute the query and then remove param by param (from the right side) until either a match is found or I run out of parameters, but can I construct a query that is more effective than that, i.e minimizing the number of calls to the db, maybe even as a single call?

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  • Select count / duplicates

    - by mike
    Hello! I have a table with all U.S. zip codes. each row contains the city and state name for the zip code. I'm trying to get a list of cities that show up in multiple states. This wouldn't be a problem if there weren't X amount of zip codes in the same city... So basically, I just want to the city in a state to count as 1 instead of it counting the city/state 7 times because there are 2+ zip codes in that city/state... I'm not really sure how to do this. I know I need to use count but how do I tell the mysql to only count a given city/state combo as 1?

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