Search Results

Search found 31367 results on 1255 pages for 'table valued parameters'.

Page 503/1255 | < Previous Page | 499 500 501 502 503 504 505 506 507 508 509 510  | Next Page >

  • customized form_for tag in rails

    - by poseid
    I want to make a table within a form by making a new form_tag. The following code in ApplicationHelper fails: module ApplicationHelper class TabularFormBuilder < ActionView::Helpers::FormBuilder # ... code to insert <tr> tags </tr> end def tabular_form_for(name, object = nil, options = nil, &proc) concat("<table>", proc.binding) form_for(name, object, (options||{}).merge(:builder => TabularFormBuilder), &proc) concat("</table>", proc.binding) end end The view I use is: <h1>New project</h1> <% tabular_form_for :project, :builder => ApplicationHelper::TabularFormBuilder do |f| %> <%= f.error_messages %> <%= f.text_field :name %> <%= f.text_area :description %> <%= f.text_field :location %> <%= f.submit 'Create' %> <% end %> The error I get is: NoMethodError in Projects#new Showing app/views/projects/new.html.erb where line #5 raised: undefined method `errors' for {:builder=ApplicationHelper::TabularFormBuilder}:Hash Any ideas how to make this custom tag work?

    Read the article

  • Dynamic SQL and Funtions

    - by Unlimited071
    Hi all, is there any way of accomplishing something like the following: CREATE FUNCTION GetQtyFromID ( @oricod varchar(15), @ccocod varchar(15), @ocmnum int, @oinnum int, @acmnum int, @acttip char(2), @unisim varchar(15) ) AS BEGIN DECLARE @Result decimal(18,8) DECLARE @SQLString nvarchar(max); DECLARE @ParmDefinition nvarchar(max); --I need to execute a query stored in a cell which returns the calculated qty. --i.e of AcuQry: select @cant = sum(smt) from table where oricod = @oricod and ... SELECT @SQLString = AcuQry FROM OinActUni WHERE (OriCod = @oricod) AND (ActTipCod = @acttip) AND (UniSim = @unisim) AND (AcuEst > 0) SET @ParmDefinition = N' @oricod varchar(15), @ccocod varchar(15), @ocmnum int, @oinnum int, @acmnum int, @cant decimal(18,8) output'; EXECUTE sp_executesql @SQLString, @ParmDefinition, @oricod = @oricod, @ccocod = @ccocod, @ocmnum = @ocmnum, @oinnum = @oinnum, @acmnum = @acmnum, @cant = @result OUTPUT; RETURN @Result END The problem with this approach is that it is prohibited to execute sp_excutesql in a function... What I need is to do something like: select id, getQtyFromID(id) as qty from table The main idea is to execute a query stored in a table cell, this is because the qty of something depends on it's unit. the unit can be days or it can be metric tons, so there is no relation between the units, therefore the need of a specific query for each unit.

    Read the article

  • find the difference between two very large list

    - by user157195
    I have two large list(could be a hundred million items), the source of each list can be either from a database table or a flat file. both lists are of comparable sizes, both unsorted. I need to find the difference between them. so I have 3 scenarios: 1. List1 is a database table(assume each row simply have one item(key) that is a string), List2 is a large file. 2. Both lists are from 2 db tables. 3. both lists are from two files. in case 2, I plan to use: select a.item from MyTable a where a.item not in (select b.item form MyTable b) this clearly is inefficient, is there a better way? Another approach is: I plan to sort each list, and then walk down both of them to find the diff. If the list is from a file, I have to read it into a db table first, then use db sorting to output the list. Is the run time complexity still O(nlogn) in db sorting? either approach is a pain and seems would be very slow when the list involved has hundreds of millions of items. any suggestions?

    Read the article

  • Union and order by

    - by David Lively
    Consider a table like tbl_ranks -------------------------------- family_id | item_id | view_count -------------------------------- 1 10 101 1 11 112 1 13 109 2 21 101 2 22 112 2 23 109 3 30 101 3 31 112 3 33 109 4 40 101 4 51 112 4 63 109 5 80 101 5 81 112 5 88 109 I need to generate a result set with the top two(2) rows for a subset of family ids (say, 1,2,3 and 4) ordered by view count. I'd like to do something like select top 2 * from tbl_ranks where family_id = 1 order by view_count union all select top 2 * from tbl_ranks where family_id = 2 order by view_count union all select top 2 * from tbl_ranks where family_id = 3 order by view_count union all select top 2 * from tbl_ranks where family_id = 4 order by view_count but, of course, order by isn't valid in a union all context in this manner. Any suggestions? I know I could run a set of 4 queries, store the results into a temp table and select the contents of that temp as the final result, but I'd rather avoid using a temp table if possible. Note: in the real app, the number of records per family id is indeterminate, and the view_counts are also not fixed as they appear in the above example.

    Read the article

  • # how to split the column values using stored procedure

    - by user1444281
    I have two tables table 1 is SELECT * FROM dbo.TBL_WD_WEB_DECK WD_ID WD_TITLE ------------------ 1 2 and data in 2nd table is WS_ID WS_WEBPAGE_ID WS_SPONSORS_ID WS_STATUS ----------------------------------------------------- 1 1 1,2,3,4 Y I wrote the following stored procedure to insert the data into both the tables catching the identity of main table dbo.TBL_WD_WEB_DECK. WD_ID is related with WS_WEBPAGE_ID. I wrote the cursor in update action to split the WS_SPONSORS_ID column calling the split function in the cursor. But it is not working. The stored procedure is: ALTER procedure [dbo].[SP_Example_SPLIT] ( @action char(1), @wd_id int out, @wd_title varchar(50), @ws_webpage_id int, @ws_sponsors_id varchar(250), @ws_status char(1) ) as begin set nocount on IF (@action = 'A') BEGIN INSERT INTO dbo.TBL_WD_WEB_DECK(WD_TITLE)VALUES(@WD_TITLE) DECLARE @X INT SET @X = @@IDENTITY INSERT INTO dbo.TBL_WD_SPONSORS(WS_WEBPAGE_ID,WS_SPONSORS_ID,WS_STATUS) VALUES (@ws_webpage_id,@ws_sponsors_id,@ws_status) END ELSE IF (@action = 'U') BEGIN UPDATE dbo.TBL_WD_WEB_DECK SET WD_TITLE = @wd_title WHERE WD_ID = @WD_ID UPDATE dbo.TBL_WD_SPONSORS SET WS_STATUS = 'N' where WS_SPONSORS_ID not in (@ws_sponsors_id) and ws_webpage_id = @wd_id BEGIN /* Declaring Cursor to split the value in ws_sponsors_id column */ Declare @var int Declare splt cursor for /* used the split function and calling the parameter in that split function */ select * from iter_simple_intlist_to_tbl(@WS_SPONSORS_ID) OPEN splt FETCH NEXT FROM splt INTO @var WHILE (@@FETCH_STATUS = 0) begin if not exists(select * from dbo.TBL_WD_SPONSORS where WS_WEBPAGE_ID = @wd_id and WS_SPONSORS_ID = @var) begin insert into dbo.TBL_WD_SPONSORS (WS_WEBPAGE_ID,WS_SPONSORS_ID) values(@wd_id,@var) end end CLOSE SPONSOR DEALLOCATE SPONSOR END END END The result I want is if I insert the data in WD_ID and IN WS_SPONSORS_ID column the data in the WS_SPONSORS_ID column should split and I need to compare it with WD_ID. The result I need is: WD_ID WD_TITLE --------------------- 1 TEST 2 TEST1 3 WS_ID WS_WEBPAGE_ID WS_SPONSORS_ID WS_STATUS -------------------------------------------------------- 1 1 1 Y 2 1 2 N 3 1 3 Y If I pass the string in WS_SPONSORS_ID as 1,2,3 it has to split like the above. Can you help?

    Read the article

  • PHP exec problem with s3-put

    - by schneck
    Hi there, I use the s3-bash-project to upload data to an S3-Bucket. My command looks like this: /mypath/s3_bash/s3-put -v -k '123456789' -s '/mypath/secret' -T '/mypath/upload/myuploadfile' '/my.bucket/mykeyname' I can run the command from the command line (Mac OS X), and it works well. Now I want to execute it from a PHP-Script: exec($command, $output); but in output, the "s3-put"-command only returns the command's help text. I log the command, and it works if I c&p it from the log the the command line, so there not a problem. It seems that PHP does not pass all the parameters to the command line, although I run escapeshellarg() over all the parameters. I'm using a local XAMPP-Test environment, safe_mode is off. Any ideas?

    Read the article

  • Displaying Query Results Horizontally

    - by AndyD273
    I am wondering if it is possible to take the results of a query and return them as a CSV string instead of as a column of cells. Basically, we have a table called Customers, and we have a table called CustomerTypeLines, and each Customer can have multiple CustomerTypeLines. When I run a query against it, I run into problems when I want to check multiple types, for instance: Select * from Customers a Inner Join CustomerTypeLines b on a.CustomerID = b.CustomerID where b.CustomerTypeID = 14 and b.CustomerTypeID = 66 ...returns nothing because a customer can't have both on the same line, obviously. In order to make it work, I had to add a field to Customers called CustomerTypes that looks like ,14,66,67, so I can do a Where a.CustomerTypes like '%,14,%' and a.CustomerTypes like '%,66,%' which returns 85 rows. Of course this is a pain because I have to make my program rebuild this field for that Customer each time the CustomerTypeLines table is changed. It would be nice if I could do a sub query in my where that would do the work for me, so instead of returning the results like: 14 66 67 it would return them like ,14,66,67, Is this possible?

    Read the article

  • MySQL null/empty-string too long for VarChar(5) ?

    - by rlb.usa
    I have a stored procedure that takes an input var_zip varchar(5). My webapp calls this procedure and gives it the parameter: cmd.Parameters.Add(new MySqlParameter("var_Zip", MySqlDbType.VarChar, 5)); cmd.Parameters["var_Zip"].Value = txtZip.Text; txtZip is empty. So it is either giving empty string '', or null. Doesn't matter to me which. But it is throwing an error: MySql.Data.MySqlClient.MySqlException: Data too long for column 'var_Zip' at row 1 What's going on and how can I fix it? I don't understand.

    Read the article

  • 2 ajax forms on the same page posting same textbox

    - by rod
    Hi All, Is it possible to post, say like a value in a textbox, to 2 different ajax forms that are on the same page? It doesn't have to be at the same time? What I'm trying to do is this: I have a search page that searches for customers and displays them on a paged grid. Users can specify up to 5 parameters (5 textboxes) to narrow the search. On the same page I have an export option. Well since I want all the customers for the search and not just the paged data I need a way to post back to the server for this option passing the same parameters used in the grid. I'm using a ViewModel which would be nice if I can pass that back to the server rather than the individual search fields that are backed by the view model. Thanks, rodchar

    Read the article

  • Count function calls by name or signature. Gcc, C++

    - by MajesticRa
    I have some c++ written package. Linux, gcc. I can modify compilation process (change Makefile, flags, etc.), but can not change C++ source code. One runs the package with different parameters, it does a job and exits. How to count: 1) Number of calls of function with specific name? 2) Number of calls of functions with specific signature? 3) Number of calls of functions where one of the parameters is of specific type i.e. std::string (type is specified by signature)? 4) and extra Number of calls of functions of STL objects, i.e. std::string copy constructor? (I mean count a number of calls during the run. ) I thought to do it with GDB, but I found it very tough to do (1) and have not found how to do (2)-(4) at all. All acceptable answers I will write here for humanity.

    Read the article

  • add parameter to links on page using jquery

    - by Priyo
    How do I add let's say something like ajax=1 to all links on my page with jquery. I will also need to check if the url has existing parameters. for example "http://mysite.com/index.php?pl=132" will have to become "http://mysite.com/index.php?pl=132&ajax=1" Also, if the link does not have any parameters, for example "http://mysite.com/index.php", it will become "http://mysite.com/index.php?ajax=1" I want to load the jquery script on document ready so all links are changed on page load. Thanks.

    Read the article

  • Reverse Search Best Practices?

    - by edub
    I'm making an app that has a need for reverse searches. By this, I mean that users of the app will enter search parameters and save them; then, when any new objects get entered onto the system, if they match the existing search parameters that a user has saved, a notification will be sent, etc. I am having a hard time finding solutions for this type of problem. I am using Django and thinking of building the searches and pickling them using Q objects as outlined here: http://www.djangozen.com/blog/the-power-of-q The way I see it, when a new object is entered into the database, I will have to load every single saved query from the db and somehow run it against this one new object to see if it would match that search query... This doesn't seem ideal - has anyone tackled such a problem before?

    Read the article

  • Intelligently removing excess indention from a string

    - by TravisO
    I'm trying to remove some excessive indention from a string, in this case it's SQL, so it can be put into a log file. So I need the find the smallest amount of indention (aka tabs) and remove it from the front of each line, but the following code ends up printing out exactly the same, any ideas? In other words, I want to take the following SELECT blah FROM table WHERE id=1 and convert it to SELECT blah FROM table WHERE id=1 here's the code I tried and fails $sql = ' SELECT blah FROM table WHERE id=1 '; // it's most likely idented SQL, remove any idention $lines = explode("\n", $sql); $space_count = array(); foreach ( $lines as $line ) { preg_match('/^(\t+)/', $line, $matches); $space_count[] = strlen($matches[0]); } $min_tab_count = min($space_count); $place = 0; foreach ( $lines as $line ) { $lines[$place] = preg_replace('/^\t{'. $min_tab_count .'}/', '', $line); $place++; } $sql = implode("\n", $lines); print '<pre>'. $sql .'</pre>';

    Read the article

  • Field to display Previous 30 Day Total

    - by whytheq
    I've got this table: CREATE TABLE #Data1 ( [Market] VARCHAR(100) NOT NULL, [Operator] VARCHAR(100) NOT NULL, [Date] DATETIME NOT NULL, [Measure] VARCHAR(100) NOT NULL, [Amount] NUMERIC(36,10) NOT NULL, --new calculated fields [DailyAvg_30days] NUMERIC(38,6) NULL DEFAULT 0 ) I've populated all the fields apart from DailyAvg_30days. This field needs to show the total for the preceding 30 days e.g. 1. if Date for a particular record is 2nd Dec then it will be the total for the period 3rd Nov - 2nd Dec inclusive. 2. if Date for a particular record is 1st Dec then it will be the total for the period 2nd Nov - 1st Dec inclusive. My attempt to try to find these totals before updating the table is as follows: SELECT a.[Market], a.[Operator], a.[Date], a.[Measure], a.[Amount], [DailyAvg_30days] = SUM(b.[Amount]) FROM #Data1 a INNER JOIN #Data1 b ON a.[Market] = b.[Market] AND a.[Operator] = b.[Operator] AND a.[Measure] = b.[Measure] AND a.[Date] >= b.[Date]-30 AND a.[Date] <= b.[Date] GROUP BY a.[Market], a.[Operator], a.[Date], a.[Measure], a.[Amount] ORDER BY 1,2,4,3 Is this a valid approach or do I need to approach this from a different angle?

    Read the article

  • How to identify each parameter type in a C# method?

    - by user465876
    I have a C# method say: MyMethod(int num, string name, Color color, MyComplexType complex) Using reflection, how can I distinctly identify each of the parameter types of any method? I want to perform some task by parameter type. If the type is simple int, string or boolean then I do something, if it is Color, XMLDocument, etc I do something else and if it is user defined type like MyComplexType or MyCalci etc then I want to do certain task. I am able to retrieve all the parameters of a method using ParameterInfo and can loop through each parameter and get their types. But how can I identify each data type? foreach (var parameter in parameters) { //identify primitive types?? //identify value types //identify reference types } Edit: this is apart of my code to create a propert grid sort of page where I want to show the parameter list with data types for the selected method. If the parameter has any userdefined type/reference type then I want to expand it further to show all the elements under it with datatypes.

    Read the article

  • '<=' operator is not working in sql server 2000

    - by Lalit
    Hello, Scenario is, database is in the maintenance phase. this database is not developed by ours developer. it is an existing database developed by the 'xyz' company in sql server 2000. This is real time database, where i am working now. I wanted to write the stored procedure which will retrieve me the records From date1 to date 2.so query is : Select * from MyTableName Where colDate>= '3-May-2010' and colDate<= '5-Oct-2010' and colName='xyzName' whereas my understanding I must get data including upper bound date as well as lower bound date. but somehow I am getting records from '3-May-2010' (which is fine but) to '10-Oct-2010' As i observe in table design , for ColDate, developer had used 'varchar' to store the date. i know this is wrong remedy by them. so in my stored procedure I have also used varchar parameters as @FromDate1 and @ToDate to get inputs for SP. this is giving me result which i have explained. i tried to take the parameter type as 'Datetime' but it is showing error while saving/altering the stored procedure that "@FromDate1 has invalid datatype", same for "@ToDate". situation is that, I can not change the table design at all. what i have to do here ? i know we can use user defined table in sql server 2008 , but there is version sql server 2000. which does not support the same. Please guide me for this scenario. **Edited** I am trying to write like this SP: CREATE PROCEDURE USP_Data (@Location varchar(100), @FromDate DATETIME, @ToDate DATETIME) AS SELECT * FROM dbo.TableName Where CAST(Dt AS DATETIME) >=@fromDate and CAST(Dt AS DATETIME)<=@ToDate and Location=@Location GO but getting Error: Arithmetic overflow error converting expression to data type datetime. in sql server 2000 What should be that ? is i am wrong some where ? also (202 row(s) affected) is changes every time in circular manner means first time sayin (122 row(s) affected) run again saying (80 row(s) affected) if again (202 row(s) affected) if again (122 row(s) affected) I can not understand what is going on ?

    Read the article

  • Adding up row number and displaying total using COUNT (PHP MySQL)

    - by Yvonne
    I'm attempting to run a query that adds up the total number of subjects in a class. A class has many subjects. There is a 'teachersclasses' table between teachers (the user table) and classes. The principles sounds pretty simple but I'm having some trouble in getting my page to display the number of subjects for each class (directly associated with the teacher) This is what I have so far, trying to make use of the COUNT with a nested SELECT: SELECT (SELECT count(*) FROM subjects WHERE subjects.classid = class.classid) AS total_subjects, class.classname, class.classid FROM class Then I am calling up 'num_subjects' to present the total within a while loop: <?php echo $row['total_subjects']?> From the above, I am receiving the total subjects for a class, but within the same table row (for one class) and my other while loop doesnt run anymore, which returns all of the classes associated with a teacher :( ... Bit of a mess now! I know to return the classes for a particular teacher, I can do an additional WHERE clause on the session of 'teacherid' but I think my query is getting too complicated for me that errors are popping up everywhere. Anyone have a quick fix for this! Thanks very much

    Read the article

  • Creating methods with infinite overloads ? (.NET)

    - by MarceloRamires
    In C# you can do this: foo = string.Format("{0} {1} {2} {3} ...", "aa", "bb", "cc" ...); This method Format() accepts infinite parameters, being the first one how the string should be formatted and the rest are values to be put in the string. Today I've come to a situation where I had to get a set of strings and test them, then I remembered this language functionality, but I had no clue. After a few unsuccessful web searches, I've realised it would be more prudent to just get an array, which didn't make me quite satisfied. Q: How do I make a function that accepts infinite parameters? And how do I use it ?

    Read the article

  • Good JDBC pattern

    - by Java Developer
    What is the good practice for database operation in Java application? Do you construct the DML syntax in the Java code and send the statements to DB engine for execution, or you just collect the parameters and then make a call to stored procedure with the parameters via java code? or neither because that's just not how to do it? can anyone give an example of a full database utility classes to do database operations in Java app? also what about the transaction manager? My assignment is to make database operation that is modular in Java. Thanks

    Read the article

  • How to use JOIN using Hibernate's session.createSQLQuery()

    - by javauser71
    Hi All, I have two Entity (tables) - Employee & Project. An Employee can have multiple Projects. Project table's CREATOR_ID field refers to Employee table's ID field. Employee entity maintains a list of Project. Using EntityManager following query works fine - "entityManager.createQuery("select e from EmployeeDTO e, ProjectDTO p where p.id = ?1 and p.creator.id=e.id"); But since I have the LAZY association relationship, I get error: "Could not initialize proxy - no Session" if I try to access Project info from Employee entity. This is expected and so I am using Hibernate's Session to create query as shown below. Session session = HibernateUtil.getSessionFactory().openSession(); org.hibernate.Query q = session.createSQLQuery("SELECT E FROM EMPLOYEE_TAB E, PROJECT_TAB P WHERE P.ID = " + projectId + " AND P.CREATOR_ID = E.ID") .addEntity("EmployeeDTO ", EmployeeDTO.class) .addEntity("ProjectDTO", ProjectDTO.class); But I get error like: "Column 'E' is either not in any table in the FROM list or appears within a join specification and is outside the scope of the join specification..." Can anyone suggest what will be the right JOIN syntax for such case? If I use ("SELECT * FROM EMPLOYEE_TAB E, ........") - it gives other error: "java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to com.im.server.dto.EmployeeDTO". Thanks in advance.

    Read the article

  • How do I compare 2 fields and return the lowest value of each record?

    - by BigRob
    I'm slowly learning access to make a database of products and suppliers for my parents' business. What i've got is a table of products indexed by our product reference and 2 more tables for 2 different suppliers that contains the suppliers product reference and price that links with our reference. I've made a query that performs a left outer join such that it returns a table of our products with each supplier's reference and price, i.e: Ref | Product Name | Supplier 1 Ref | Supplier 1 Price | Supplier 2 Ref | Supplier 2 Price Here's the query I used: SELECT Catalog.Ref, Catalog.[Product Name], Catalog.Price, [D Products].[Supplier Ref], [D Products].Cost, [GS Products].[Supplier Ref], [GS Products].Cost FROM ([Catalog] LEFT JOIN [D Products] ON Catalog.Ref = [D Products].Ref) LEFT JOIN [GS Products] ON Catalog.Ref = [GS Products].Ref; Not all products are available from both suppliers, hence the outer join. What I want to do (with a query?) is to take the table produced by the query above and simply show the product reference, cheapest supplier reference and cheapest supplier price, i.e: Ref | Cheapest Suppplier Ref | Cheapest Supplier Price Unfortunately my SQL knowledge isn't quite good enough to figure this out, but if anyone can help i'd really appreciate it. Thanks, Rob

    Read the article

  • hash tables and 2d vectors

    - by Sunil
    I want to push a 2d vector into a hash table row by row and later search for a row (vector) in the hash table and want to be able to find it. I want to do something like #include <iostream> #include <set> #include <vector> using namespace std; int main(){ std::set < vector<int> > myset; vector< vector<int> > v; int k = 0; for ( int i = 0; i < 5; i++ ) { v.push_back ( vector<int>() ); for ( int j = 0; j < 5; j++ ) v[i].push_back ( k++ ); } for ( int i = 0; i < 5; i++ ) { std::copy(v[i].begin(),v[i].end(),std::inserter(myset)); // This is not correct but what is the right way ? // and also here, I want to search for a particular vector if it exists in the table. for ex. the second row of vector v. } return 0; } I'm not sure how to insert and look up a vector in a set. So if nybody could guide me, it will be helpful. Thanks

    Read the article

  • ASP.NET MVC: How to show value in a label from selected Drop Down List item?

    - by Lillie
    Hi! I'm trying to show a value of selected Drop Down List item in a label. I managed to make this work with Web Forms but with MVC I'm totally lost. My Index looks like this: [...] <% using (Html.BeginForm()) { %> <table> <tr> <td>Processor</td> <td><%= Html.DropDownList("lstProcessor1", new SelectList((IEnumerable)ViewData["Processor1List"], "product_price", "product_description")) %></td> </tr> <tr> <td>Total Amount</td> <td>0,00 €</td> </tr> </table> <input type="submit" value="Submit" /> <% } %> [...] And my HomeController starts with: using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; using System.Web.Mvc.Ajax; using MvcApplication1.Models; namespace MvcApplication1.Controllers { [HandleError] public class HomeController : Controller { // Connect database DB50DataContext _ctx = new DB50DataContext(); // GET: /Home/ public ActionResult Index() { // Search: Processors var products = from prod in _ctx.products where prod.product_searchcode == "processor1" select prod; ViewData["Processort1List"] = products; return View(); } I would like the product_price to show on the second line of the table, where it now says 0,00 €. It should also update the price automatically when the item from the Drop Down List is changed. I guess I should use JQuery but I have no idea how. Could someone please give me some tips how to do this?

    Read the article

  • Using ddply() to Get Frequency of Certain IDs, by Appearance in Multiple Rows (in R)

    - by EconomiCurtis
    Goal If the following description is hard follow, please see the example "before" and "after" to see a straightforward example. I have bartering data, with unique trade ids, and two sides of the trade. Side1 and Side2 are baskets, lists of item ids that represent both sides of the barter transaction. I'd like to count the frequency each ITEM appears in TRADES. E.g, if item "001" appeared in 3 trades, I'd have a count of 3 (ignoring how many times the item appeared in each trade). Further, I'd like to do this with the plyr ddply function. (If you're interested as to my motivation, I working over many hundreds of thousands of transactions and am already using a ddply to calculate several other summary statistics. I'd like to add this to the ddply I'm already using, rather than calculate it after, and merge it into the ddply output.... sorry if that was difficult to follow.) In terms of pseudo code I'm working off of: merge each row of Side1 and Side2 by row, get unique() appearances of each item id apply table() function transpose and relabel output from table Example of the structure of my data, and the output I desire. Data Example (before): df <- data.frame(TradeID = c("01","02","03","04")) df$Side1 = list(c("001","001","002"), c("002","002","003"), c("001","004"), c("001","002","003","004")) df$Side2 = list(c("001"),c("007"),c("009"),c()) Desired Output (after): df.ItemRelFreq_byTradeID <- data.frame(ItemID = c("001","002","003","004","007","009"), RelFreq_byTrade = c(3,3,2,2,1,1)) One method to do this without ddply I've worked out one way to do this below. My problem is that I can't quite seem to get ddply to do this for me. temp <- table(unlist(sapply(mapply(c,df$Side1,df$Side2), unique))) df.ItemRelFreq_byTradeID <- data.frame(ItemID = names(temp), RelFreq_byTrade = temp[]) Thanks for any help you can offer! Curtis

    Read the article

  • Is my approach for persistent login secure ?

    - by Jay
    I'm very much stuck with the reasonable secure approach to implement 'Remember me' feature in a login system. Here's my approach so far, Please advice me if it makes sense and is reasonably secure: Logging: User provides email and password to login (both are valid).. Get the user_id from DB Table Users by comparing provided email Generate 2 random numbers hashed strings: key1, key2 and store in cookies. In DB Table COOKIES, store key1, key2 along with user_id. To Check login: If key1 and key2 both cookies exist, validate both keys in DB Table COOKIES (if a row with key1, and key2 exists, user is logged). if cookie is valid, regenrate key2 and update it in cookie and also database. Why re-genrating key: Because if someone steals cookie and login with that cookie, it will be working only until the real user login. When the real user will login, the stolen cookie will become invalid. Right? Why do I need 2 keys: Because if i store user_id and single key in cookie and database, and the user want to remember the password on another browser, or computer, then the new key will be updated in database, so the user's cookie in earlier browser/PC will become invalid. User wont be able to remember password on more than one place. Thanks for your opinions.

    Read the article

< Previous Page | 499 500 501 502 503 504 505 506 507 508 509 510  | Next Page >