Search Results

Search found 18028 results on 722 pages for 'atomic values'.

Page 268/722 | < Previous Page | 264 265 266 267 268 269 270 271 272 273 274 275  | Next Page >

  • how can i set up a uniqueness constraint in mysql for columns that can be null?

    - by user299689
    I know that in MySQL, UNIQUE constraits don't treat NULL values as equal. So if I have a unique constraint on ColumnX, then two separate rows can have values of NULL for ColumnX and this wouldn't violate the constraint. How can I work around this? I can't just set the value to an arbitrary constant that I can flag, because ColumnX in my case is actually a foreign key to another table. What are my options here? Please note that this table also has an "id" column that is its primary key. Since I'm using Ruby on Rails, it's important to keep this id column as the primary key. Note 2: In reality, my unique key encompasses many columns, and some of them have to be null, because they are foreign keys, and only one of them should be non-null. What I'm actually trying to do is to "simulate" a polymorphic relationship in a way that keep referential integrity in the db, but using the technique outlined in the first part of the question asked here: http://stackoverflow.com/questions/922184/why-can-you-not-have-a-foreign-key-in-a-polymorphic-association

    Read the article

  • Am I trying to Implement Multiple Inheritance. How can I do this.

    - by Shantanu Gupta
    I have created a class say A which has some functions defined as protected. Now Class B inherits A and class C inherits B. Class A has private default constructor and protected parameterized constructor. I want Class B to be able to access all the protected functions defined in Class A but class C can have access on some of the functions only not all the functions and class C is inheriting class B. How can I restrict access to some of the functions of Class A from Class C ? EDIT: namespace Db { public Class A { private A(){} protected A(string con){assign this value} protected DataTable getTable(){return Table;} protected Sqlparameters setParameters(){return parameter;} } } namespace Data { public Class B:A { protected B():base("constring"){} protected DataTable output(){return getTable();} protected sqlparameter values(param IDataParameter[] parameter){} } } namespace Bsns { public Class C:B { protected C():base(){} protected DataTable show() {return values(setparameter());} } } EDIT I think what I am trying to do here is Multiple inheritance. Please check. Class A { //suppose 10 functions are declared } Class B:A { //5 functions declared which are using A's function in internal body } Class C:B { //using all functions of B but require only 4 functions of A to be accessible by C. }

    Read the article

  • Drupal 6 - I am using drupal_execute to insert a CCK node into my site. Everything is working excep

    - by rdurbin
    $form_state['values']['field_prx_mp3_labels'][0][value] = $mp3_labels; $form_state['values']['taxonomy'][0][value] = array('tags'=>array('1'=>'Music')); $errs = drupal_execute('prx_content_node_form', $form_state, (object) $nodeTmp); This is a Drupal 6 site. I am using drupal_execute to create a node programatically. The first line is working for field_prx_mp3_labels. The second (for taxonomy) is not. Here is what my select on the node add for my cck looks like: <select name="taxonomy[2][]" multiple="multiple" class="form-select" id="edit-taxonomy-2" size="9"><option value="">- None -</option><option value="5">Music</option><option value="6">-Rock/Pop</option><option value="7">-Jazz/Blues</option><option value="8">-Classical</option><option value="9">-Music Documentaries</option><option value="10">-Festivals/Concerts</option><option value="11">Arts</option><option value="19">-Literature</option><option value="12">Nature</option><option value="13">History</option><option value="15">-Music</option><option value="14">Culture</option><option value="17">-American Indian</option><option value="18">-Latino</option><option value="16">-Youth Perspective</option></select> I have tried many many variations for line 2 (relating to the taxonomy). This comment seemed close but it hasn't worked for me: http://drupal.org/node/178506#comment-1155576 Thanks!

    Read the article

  • C++: defining maximum/minimum limits for a class

    - by Luis
    Basically what the title says... I have created a class that models time slots in a variable-granularity daily schedule (where for example the first time slot is 30 minutes, but the second time slot can be 40 minutes); the first available slot starts at (a value comparable to) 1. What I want to do now is to define somehow the maximum and minimum allowable values that this class takes and I have two practical questions in order to do so: 1.- does it make sense to define absolute minimum and maximum in such a way for a custom class? Or better, does it suffice that a value always compares as lower-than any other possible value of the type, given the class's defined relational operators, to be defined the min? (and analogusly for the max) 2.- assuming the previous question has an answer modeled after "yes" (or "yes but ..."), how do I define such max/min? I know that there is std::numeric_limits<> but from what I read it is intended for "numeric types". Do I interpret that as meaning "represented as a number" or can I make a broader assumption like "represented with numbers" or "having a correspondence to integers"? After all, it would make sense to define the minimum and maximum for a date class, and maybe for a dictionary class, but numeric_limits may not be intended for those uses (I don't have much experience with it). Plus, numeric_limits has a lot of extra members and information that I don't know what to make with. If I don't use numeric_limits, what other well-known / widely-used mechanism does C++ offer to indicate the available range of values for a class?

    Read the article

  • How to optimize a postgreSQL server for a "write once, read many"-type infrastructure ?

    - by mhu
    Greetings, I am working on a piece of software that logs entries (and related tagging) in a PostgreSQL database for storage and retrieval. We never update any data once it has been inserted; we might remove it when the entry gets too old, but this is done at most once a day. Stored entries can be retrieved by users. The insertion of new entries can happen rather fast and regularly, thus the database will commonly hold several millions elements. The tables used are pretty simple : one table for ids, raw content and insertion date; and one table storing tags and their values associated to an id. User search mostly concern tags values, so SELECTs usually consist of JOIN queries on ids on the two tables. To sum it up : 2 tables Lots of INSERT no UPDATE some DELETE, once a day at most some user-generated SELECT with JOIN huge data set What would an optimal server configuration (software and hardware, I assume for example that RAID10 could help) be for my PostgreSQL server, given these requirements ? By optimal, I mean one that allows SELECT queries taking a reasonably little amount of time. I can provide more information about the current setup (like tables, indexes ...) if needed.

    Read the article

  • How do I get flashvars in Firefox using object embed tag only to work?

    - by Liam
    I am trying to generate an <object> tag only embed code and cannot get Firefox to pass Flash along the FlashVars values. This seems to work everyplace else that I've tried it but fails in Firefox. Here is a sample of the embed that I'm using: <object type="application/x-shockwave-flash" classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=10,0,0,0" width="550" height="400" id="Main" align="middle"> <param name="movie" value="Main.swf" /> <param name="allowScriptAccess" value="always" /> <param name="allowFullScreen" value="true" /> <param name="bgcolor" value="#ffffff" /> <param name="quality" value="high" /> <param name="menu" value="false" /> <param name="FlashVars" value="foo=1" /> </object> Please note that the Flash experience does show up in Firefox but when I do traces and actually run the application this fails to read the values. This has had me scratching my head for a day and I'm pretty stumped. If anyone has any guidance on this it would relly be appreciated.

    Read the article

  • c# finding matching words in table column using Linq2Sql

    - by David Liddle
    I am trying to use Linq2Sql to return all rows that contain values from a list of strings. The linq2sql class object has a string property that contains words separated by spaces. public class MyObject { public string MyProperty { get; set; } } Example MyProperty values are: MyObject1.MyProperty = "text1 text2 text3 text4" MyObject2.MyProperty = "text2" For example, using a string collection, I pass the below list var list = new List<>() { "text2", "text4" } This would return both items in my example above as they both contain "text2" value. I attempted the following using the below code however, because of my extension method the Linq2Sql cannot be evaluated. public static IQueryable<MyObject> WithProperty(this IQueryable<MyProperty> qry, IList<string> p) { return from t in qry where t.MyProperty.Contains(p, ' ') select t; } I also wrote an extension method public static bool Contains(this string str, IList<string> list, char seperator) { if (String.IsNullOrEmpty(str) || list == null) return false; var splitStr = str.Split(new char[] { seperator }, StringSplitOptions.RemoveEmptyEntries); foreach (string s in splitStr) foreach (string l in list) if (String.Compare(s, l, true) == 0) return true; return false; } Any help or ideas on how I could achieve this?

    Read the article

  • Char C question about encoding signed/unsigned.

    - by drigoSkalWalker
    Hi guys. I read that C not define if a char is signed or unsigned, and in GCC page this says that it can be signed on x86 and unsigned in PowerPPC and ARM. Okey, I'm writing a program with GLIB that define char as gchar (not more than it, only a way for standardization). My question is, what about UTF-8? It use more than an block of memory? Say that I have a variable unsigned char *string = "My string with UTF8 enconding ~ çã"; See, if I declare my variable as unsigned I will have only 127 values (so my program will to store more blocks of mem) or the UTF-8 change to negative too? Sorry if I can't explain it correctly, but I think that i is a bit complex. NOTE: Thanks for all answer I don't understand how it is interpreted normally. I think that like ascii, if I have a signed and unsigned char on my program, the strings have diferently values, and it leads to confuse, imagine it in utf8 so.

    Read the article

  • What's a good way to parameterize "static" content (e.g. CSS) in a Tomcat webapp?

    - by Steven Huwig
    Some of our CSS files contain parameters that can vary based on the deployment location (dev, QA, prod). For example: background: url(#DOJO_PATH#/dijit/themes...) to avoid hardcoding a path to a particular CDN or locally-hosted Dojo installation. These values are textually substituted with the real values by a deployment script, when it copies the contents of the webapp into the Tomcat webapps directory. That way the same deployment archive file (WAR + TAR file containing other configuration) can be deployed to dev, QA, and prod, with the varying parameters provided by environment-specific configuration files. However, I'd like to make the contents of the WAR (including the templatized CSS files) independent of this in-house deployment script. Since we don't really have control over the deployment script, all I can think to do is configure Tomcat with #DOJO_PATH# etc. as environment variables in the application's context.xml, and use Tomcat to insert those parameters into the CSS at runtime. I could make the CSS files into generated JSPs, but it seems a little ugly to me. Moreover, the substitution only needs to be done once per application deployment, so repeatedly dynamically generating the stylesheets using JSP will be rather wasteful. Does anyone have any alternative ideas or tools to use for this? We're committed to Tomcat and to substituting these parameters at deployment or at runtime (that is, not at build time).

    Read the article

  • How to make command-line options mandatory with GLib?

    - by ahe
    I use GLib to parse some command-line options. The problem is that I want to make two of those options mandatory so that the program terminates with the help screen if the user omits them. My code looks like this: static gint line = -1; static gint column = -1; static GOptionEntry options[] = { {"line", 'l', 0, G_OPTION_ARG_INT, &line, "The line", "L"}, {"column", 'c', 0, G_OPTION_ARG_INT, &column, "The column", "C"}, {NULL} }; ... int main(int argc, char** argv) { GError *error = NULL; GOptionContext *context; context = g_option_context_new ("- test"); g_option_context_add_main_entries (context, options, NULL); if (!g_option_context_parse(context, &argc, &argv, &error)) { usage(error->message, context); } ... return 0; } If I omit one of those parameters or both on the command-line g_option_context_parse() still succeeds and the values in question (line and or column) are still -1. How can I tell GLib to fail parsing if the user doesn't pass both options on the command-line? Maybe I'm just blind but I couldn't find a flag I can put into my GOptionEntry data structure to tell it to make those fields mandatory. Of course I could check if one of those variables is still -1 but then the user could just have passed this value on the command-line and I want to print a separate error message if the values are out of range.

    Read the article

  • DB Design to store custom fields for a table

    - by Fazal
    Hi All, this question came up based on the responses I got for the question http://stackoverflow.com/questions/2785033/getting-wierd-issue-with-to-number-function-in-oracle As everyone suggested that storing Numeric values in VARCHAR2 columns is not a good practice (which I totally agree with), I am wondering about a basic Design choice our team has made and whether there are better way to design. Problem Statement : We Have many tables where we want to give certain number of custom fields. The number of required custom fields is known, but what kind of attribute is mapped to the column is available to the user E.g. I am putting down a hypothetical scenario below Say you have a laptop which stores 50 attribute values for every laptop record. Each laptop attributes are created by the some admin who creates the laptop. A user created a laptop product lets say lap1 with attributes String, String, numeric, numeric, String Second user created laptop lap2 with attributes String,numeric,String,String,numeric Currently there data in our design gets persisted as following Laptop Table Id Name field1 field2 field3 field4 field5 1 lap1 lappy lappy 12 13 lappy 2 lap2 lappy2 13 lappy2 lapp2 12 This example kind of simulates our requirement and our design Now here if somebody is lookinup records for lap2 table doing a comparison on field2, We need to apply TO_NUMBER. select * from laptop where name='lap2' and TO_NUMBER(field2) < 15 TO_NUMBER fails in some cases when query plan decides to first apply to_number instead of the other filter. QUESTION Is this a valid design? What are the other alternative ways to solve this problem One of our team mates suggested creating tables on the fly for such cases. Is that a good idea How do popular ORM tools give custom fields or flex fields handling? I hope I was able to make sense in the question. Sorry for such a long text.. This causes us to use TO_NUMBER when queryio

    Read the article

  • Python: eliminating stack traces into library code?

    - by Mark Harrison
    When I get a runtime exception from the standard library, it's almost always a problem in my code and not in the library code. Is there a way to truncate the exception stack trace so that it doesn't show the guts of the library package? For example, I would like to get this: Traceback (most recent call last): File "./lmd3-mkhead.py", line 71, in <module> main() File "./lmd3-mkhead.py", line 66, in main create() File "./lmd3-mkhead.py", line 41, in create headver1[depotFile]=rev TypeError: Data values must be of type string or None. and not this: Traceback (most recent call last): File "./lmd3-mkhead.py", line 71, in <module> main() File "./lmd3-mkhead.py", line 66, in main create() File "./lmd3-mkhead.py", line 41, in create headver1[depotFile]=rev File "/usr/anim/modsquad/oses/fc11/lib/python2.6/bsddb/__init__.py", line 276, in __setitem__ _DeadlockWrap(wrapF) # self.db[key] = value File "/usr/anim/modsquad/oses/fc11/lib/python2.6/bsddb/dbutils.py", line 68, in DeadlockWrap return function(*_args, **_kwargs) File "/usr/anim/modsquad/oses/fc11/lib/python2.6/bsddb/__init__.py", line 275, in wrapF self.db[key] = value TypeError: Data values must be of type string or None.

    Read the article

  • Domain validates but won't save

    - by marko
    I have the following setup. Class, say, Car that has a CarPart (belongsTo=[car:Car]). When I'm creating a Car I also want to create som default CarParts, so I do def car = new Car(bla bla bla) def part = new CarPart(car:car) Now, when I do car.validate() or part.validate() it seems fine. But when I do if(car.save && part.save() I get this exception: 2012-03-24 14:02:21,943 [http-8080-4] ERROR util.JDBCExceptionReporter - Batch entry 0 insert into car_part (version, car_id, id) values ('0', '297', '298') was aborted. Call getNextException to see the cause. 2012-03-24 14:02:21,943 [http-8080-4] ERROR util.JDBCExceptionReporter - ERROR: value too long for type character varying(6) 2012-03-24 14:02:21,943 [http-8080-4] ERROR events.PatchedDefaultFlushEventListener - Could not synchronize database state with session org.hibernate.exception.DataException: Could not execute JDBC batch update Stacktrace follows: java.sql.BatchUpdateException: Batch entry 0 insert into car_part (version, deal_id, id) values ('0', '297', '298') was aborted. Call getNextException to see the cause. at org.postgresql.jdbc2.AbstractJdbc2Statement$BatchResultHandler.handleError(AbstractJdbc2Statement.java:2621) at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1837) at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:407) at org.postgresql.jdbc2.AbstractJdbc2Statement.executeBatch(AbstractJdbc2Statement.java:2754) at $Proxy20.flush(Unknown Source) at ristretto.DealController$_closure5.doCall(DealController.groovy:109) at ristretto.DealController$_closure5.doCall(DealController.groovy) at java.lang.Thread.run(Thread.java:722) Any ideas?

    Read the article

  • Mysql count and sum from two diferent tables

    - by Agent_x
    Hi all, i have a problem with some querys in php and mysql: I have 2 diferent tables with one field in common: table 1 id | hits | num_g | cats | usr_id |active 1 | 10 | 11 | 1 | 53 | 1 2 | 13 | 16 | 3 | 53 | 1 1 | 10 | 22 | 1 | 22 | 1 1 | 10 | 21 | 3 | 22 | 1 1 | 2 | 6 | 2 | 11 | 1 1 | 11 | 1 | 1 | 11 | 1 table 2 id | usr_id | points 1 | 53 | 300 Now i use this statement to sum just the total from the table 1 every id count + 1 too SELECT usr_id, COUNT( id ) + SUM( num_g + hits ) AS tot_h FROM table1 WHERE usr_id!='0' GROUP BY usr_id ASC LIMIT 0 , 15 and i get the total for each usr_id usr_id| tot_h | 53 | 50 22 | 63 11 | 20 until here all is ok, now i have a second table with extra points (table2) I try this: SELECT usr_id, COUNT( id ) + SUM( num_g + hits ) + (SELECT points FROM table2 WHERE usr_id != '0' ) AS tot_h FROM table1 WHERE usr_id != '0' GROUP BY usr_id ASC LIMIT 0 , 15 but it seems to sum the 300 extra points to all users: usr_id| tot_h | 53 | 350 22 | 363 11 | 320 Now how i can get the total like the first try but + the secon table in one statement? because now i have just one entry in the second table but i can be more there. thanks for all the help. =============================================================================== hi thomas thanks for your reply, i think is in the right direction, but im getting weirds results, like usr_id | tot_h 22 | NULL <== i think the null its because that usr_id as no value in the table2 53 | 1033 Its like the second user is getting all the the values. then i try this one: SELECT table1.usr_id, COUNT( table1.id ) + SUM( table1.num_g + table1.hits + table2.points ) AS tot_h FROM table1 LEFT JOIN table2 ON table2.usr_id = table1.usr_id WHERE table1.usr_id != '0' AND table2.usr_id = table1.usr_id GROUP BY table1.usr_id ASC Same result i just get the sum of all values and not by each user, i need something like this result: usr_id | tot_h 53 | 53 <==== plus 300 points on table1 22 | 56 <==== plus 100 points on table2 /////////the result i need //////////// usr_id | tot_h 53 | 353 <==== plus 300 points on table2 22 | 156 <==== plus 100 points on table2 I think the structure need to be something like this Pseudo statements ;) from table1 count all id to get the number of record where the usr_id are then sum hits + num_g and from table2 select the extra points where the usr_id are the same as table1 and get teh result: usr_id | tot_h 53 | 353 22 | 156

    Read the article

  • Use of unassigned local variable 'xxx'

    - by Tomislav
    I'm writing a database importer from our competitors to ours database:) I have a code generator which create Methods form import to our database like public void Test_Import_Customer_1() // variables string conn; string sqlSelect; string sqlInsert; int extID; string name; string name2; DateTime date_inserted; sqlSelect="select id,name,date_inserted from table_competitors_1"; oledbreader reader = new GetOledbRader(sqlString,conn); while (reader.read()) { name=left((string)myreader["name"],50); //limitation of my field date_inserted=myreader["date_inserted"]; sqlInsert=string.Format("insert into table(name,name2,date_inserted)values '{0}', '{1}', {2})",name,name2,date_inserted); //here is the problem name2 "Use of unassigned local variable" ExecuteSQL(sqlInsert) } As different companies database has different fields i can not set value to each variable and there is a big number of tables to go one variable to next. like sqlSelect_Company_1 = "select name,date_inserted from table_1"; sqlSelect_Company_2 = "select name,name2 from table_2"; is there a way to override the typing of each variable one by one with default values?

    Read the article

  • Java string to double conversion.

    - by wretrOvian
    Hi, I've been reading up on the net about the issues with handling float and double types in java. Unfortunately, the image is still not clear. Hence, i'm asking here direct. :( My MySQL table has various DECIMAL(m,d) columns. The m may range from 5 to 30. d stays a constant at 2. Question 1. What equivalent data-type should i be using in Java to work (i.e store, retrieve, and process) with the size of the values in my table? (I've settled with double - hence this post). Question 2. While trying to parse a double from a string, i'm getting errors Double dpu = new Double(dpuField.getText()); for example - "1" -> java.lang.NumberFormatException: empty String "10" -> 1.0 "101" -> 10.0 "101." -> 101.0 "101.1" -> 101.0 "101.19" -> 101.1 What am i doing wrong? What is the correct way to convert a string to a double value? And what measures should i take to perform operations on such values?

    Read the article

  • iphone - why is this flip animation using layers not working?

    - by Digital Robot
    I would like to make an animation that goes like this: imagine a picture sitting on a shelve. It drops from the shelve and as it falls it rotates along the horizontal axis and translates along the vertical axis. I would like to do this with perspective and the back side should be the image reversed, like the picture is a kind of slide. I have done this: CALayer* layer = myImageView.layer; layer.doubleSided = YES; CAKeyframeAnimation* animationTransform = [CAKeyframeAnimation animationWithKeyPath:@"transform"]; CATransform3D startTransform = CATransform3DIdentity; CATransform3D endTransform = CATransform3DTranslate (layer.transform, 0.0f, 200.0f, 0.0f); endTransform = CATransform3DRotate (endTransform, degreesToRadian(350.0f), 1.0f, 0.0f, 0.0f); endTransform.m34 = 1.0 / -500; NSArray *values = [NSArray arrayWithObjects: [NSValue valueWithCATransform3D:startTransform], [NSValue valueWithCATransform3D:endTransform], nil]; [animationTransform setValues:values]; NSArray *tempos = [NSArray arrayWithObjects: [NSNumber numberWithFloat:0.0f], [NSNumber numberWithFloat:0.7f], nil]; [animationTransform setKeyTimes:tempos]; NSArray *timing = [NSArray arrayWithObjects: [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut], nil]; [animationTransform setTimingFunctions:timing]; animationTransform.fillMode = kCAFillModeRemoved; animationTransform.removedOnCompletion = YES; animationTransform.repeatCount = 1; animationTransform.duration = 3.7f; animationTransform.cumulative = YES; the result of this has nothing to do with anything. The result is: the image translates down an inch on the screen and then up half inch. Then it disappears and appears at its starting position again. What am I missing? thanks

    Read the article

  • How to amend return value design in OO manner?

    - by FrontierPsycho
    Hello. I am no newb on OO programming, but I am faced with a puzzling situation. I have been given a program to work on and extend, but the previous developers didn't seem that comfortable with OO, it seems they either had a C background or an unclear understanding of OO. Now, I don't suggest I am a better developer, I just think that I can spot some common OO errors. The difficult task is how to amend them. In my case, I see a lot of this: if (ret == 1) { out.print("yadda yadda"); } else if (ret == 2) { out.print("yadda yadda"); } else if (ret == 3) { out.print("yadda yadda"); } else if (ret == 0) { out.print("yadda yadda"); } else if (ret == 5) { out.print("yadda yadda"); } else if (ret == 6) { out.print("yadda yadda"); } else if (ret == 7) { out.print("yadda yadda"); } ret is a value returned by a function, in which all Exceptions are swallowed, and in the catch blocks, the above values are returned explicitly. Oftentimes, the Exceptions are simply swallowed, with empty catch blocks. It's obvious that swalllowing exceptions is wrong OO design. My question concerns the use of return values. I believe that too is wrong, however I think that using Exceptions for control flow is equally wrong, and I can't think of anything to replace the above in a correct, OO manner. Your input, please?

    Read the article

  • XUL: Printing value from SQL query without using value attribute

    - by Grip
    I want to print the results of an SQL query in XUL with word-wrapping using the description tag. I have the following code: <grid> <columns> <column flex="2" /> <column flex="1" /> </columns> <rows datasources="chrome://glossary/content/db/development.sqlite3" ref="?" querytype="storage" > <template> <query>select distinct * from Terms</query> <action> <row uri="?"> <description value="?name" /> <description value="?desc" /> </row> </action> </template> </rows> This works for printing the data, but since I'm using the value attribute of description, there's no word-wrapping. I don't understand entirely what I'm doing with the value attribute, but I don't seem to be able to get the values of my SQL query in any other way. So, how could I get those values without the value tag? Thanks.

    Read the article

  • Dictionaries with more than one key per value in Python

    - by nickname
    I am attempting to create a nice interface to access a data set where each value has several possible keys. For example, suppose that I have both a number and a name for each value in the data set. I want to be able to access each value using either the number OR the name. I have considered several possible implementations: Using two separate dictionaries, one for the data values organized by number, and one for the data values organized by name. Simply assigning two keys to the same value in a dictionary. Creating dictionaries mapping each name to the corresponding number, and vice versa Attempting to create a hash function that maps each name to a number, etc. (related to the above) Creating an object to encapsulate all three pieces of data, then using one key to map dictionary keys to the objects and simply searching the dictionary to map the other key to the object. None of these seem ideal. The first seems ugly and unmaintainable. The second also seems fragile. The third/fourth seem plausible, but seem to require either much manual specification or an overly complex implementation. Finally, the fifth loses constant-time performance for one of the lookups. In C/C++, I believe that I would use pointers to reference the same piece of data from different keys. I know that the problem is rather similar to a database lookup problem by a non-key column, however, I would like (if possible), to maintain the approximate O(1) performance of Python dictionaries. What is the most Pythonic way to achieve this data structure?

    Read the article

  • Core Data object into an NSDictionary with possible nil objects

    - by Chuck
    I have a core data object that has a bunch of optional values. I'm pushing a table view controller and passing it a reference to the object so I can display its contents in a table view. Because I want the table view displayed a specific way, I am storing the values from the core data object into an array of dictionaries then using the array to populate the table view. This works great, and I got editing and saving working properly. (i'm not using a fetched results controller because I don't have anything to sort on) The issue with my current code is that if one of the items in the object is missing, then I end up trying to put nil into the dictionary, which won't work. I'm looking for a clean way to handle this, I could do the following, but I can't help but feeling like there's a better way. *passedEntry is the core data object handed to the view controller when it is pushed, lets say it contains firstName, lastName, and age, all optional. if ([passedEntry firstName] != nil) { [dictionary setObject:[passedEntry firstName] forKey:@"firstName"] } else { [dictionary setObject:@"" forKey:@"firstName"] } And so on. This works, but it feels kludgy, especially if I end up adding more items to the core data object down the road.

    Read the article

  • PHP - Drilling down Data and Looping with Loops

    - by stogdilla
    I'm currently having difficulty finding a way of making my loops work. I have a table of data with 15 minute values. I need the data to pull up in a few different increments $filters=Array('Yrs','Qtr','Day','60','30','15'); I think I have a way of finding out what I need to be able to drill down to but the issue I'm having is after the first loop to cycle through all the Outter most values (ex: the user says they want to display by Hours, each hour should be able to have a "+" that will then add a new div to display the half hour data, then each half hour data have a "+" to display the 15 minute data upon request. Now I can just program the number of outputs for each value (6 different outputs) just in-case... but isn't there a way I can make it do the drill down for each one in a loop? so I only have to code one output once and have it just check if there are any more intervals after it and check for those? I'm sure I'm just overlooking some very simple way of doing this but my brain isn't being clever today. Sorry in advance if this is a simple solution. I guess the best way I could think of it as a reply on a form. How you would check to see if it's a reply of a reply, and then if that reply has any replys...etc for output. Can anyone help or at least point me in the right direction? Or am I stuck coding each possible check? Thanks in advance!

    Read the article

  • Reading XML or objects from a Web service

    - by Shawn
    This is my first time working with webservices and I am a bit lost. I successfully called the functions, but I only can get one value from the service. I read that the easiest way is to read xml or create objects and then call their values. Currently I use functions that return the desired value but I need to call them 3 times to get all the data witch is a waste of time and resources. I tried to call the service with the URL and use it as a website or getting the service to work the same way without importing into the program. The thing is that i cant find a way to pass the values into the url, because of that i get only blank pages. What is the fastest way to get my data from the services? I need city name, temperature and a flag if the city is valid. I need to pass the zip code to the service. Thank you. My current code wetther.Weather wether = new wetther.Weather(); string farenhait = wether.GetCityWeatherByZIP(zip).Temperature; string city = wether.GetCityWeatherByZIP(zip).City; bool correct = wether.GetCityWeatherByZIP(zip).Success; I tried it that way // Retrieve XML document XmlTextReader reader = new XmlTextReader("http://xml.weather.yahoo.com/forecastrss?p=94704"); // Skip non-significant whitespace reader.WhitespaceHandling = WhitespaceHandling.Significant; // Read nodes one at a time while (reader.Read()) { // Print out info on node Console.WriteLine("{0}: {1}", reader.NodeType.ToString(), reader.Name); } This one works for the yahoo page but not for mine. I need to use this webservice - http://wsf.cdyne.com/WeatherWS/Weather.asmx

    Read the article

  • jQuery indexOf select box manipulation

    - by kenny99
    Hi, I'm trying to figure out how to remove options from a select box when that option has been selected in an adjacent select box. Basically the user has the option to add multiple records here via select boxes, but I want to remove the list of options available to them so that, for example, they can't enter the same value in two select boxes. When an Add More button is clicked, I fade in the next select box container. A number of select boxes have been generated by PHP and I use JS to hide them. Each select box has a unique number appended to the ID, so i want to access those select boxes which contain the string "other_pet_types", then I want to iterate through the currently visible ones and build an array of the values which have been selected, which I will then remove from the list of options in the newly displayed select box. This is what I have so far, but it's definitely not right - I can't get the initial test on the ID to work. Any pointers greatly appreciated as i realise i'm pretty wide of the mark at the moment! var vals = new Array(); //build array with currently selected options $('p.mult_entries select').each(function(){ vals += $(this).val(); }); $("p.mult_entries:hidden:first").fadeIn("slow", function() { $(this).find(('select').attr('id').indexOf('other_pet_types') > 0).each(function(){ console.log($(this).val()); //as expected prints nothing - need to iterate through the options of the above select //once i extract the correct values, iterate through new select box and use inArray to remove options where that value already exists in one of previous select boxes }); });

    Read the article

  • Rollback doesn't work in MySQLdb

    - by Anton Barycheuski
    I have next code ... db = MySQLdb.connect(host=host, user=user, passwd=passwd, db=db, charset='utf8', use_unicode=True) db.autocommit(False) cursor = db.cursor() ... for col in ws.columns[1:]: data = (col[NUM_ROW_GENERATION].value, 1, type_topliv_dict[col[NUM_ROW_FUEL].value]) fullgeneration_id = data[0] type_topliv = data[2] if data in completions_set: compl_id = completions_dict[data] else: ... sql = u"INSERT INTO completions (type, mark, model, car_id, type_topliv, fullgeneration_id, mark_id, model_id, production_period, year_from, year_to, production_period_url) VALUES (1, '%s', '%s', 0, %s, %s, %s, %s, '%s', '%s', '%s', '%s')" % (marks_dict[mark_id], models_dict[model_id], type_topliv, fullgeneration_id, mark_id, model_id, production_period, year_from, year_to, production_period.replace(' ', '_').replace(u'?.?.', 'nv') ) inserted_completion += cursor.execute(sql) cursor.execute("SELECT fullgeneration_id, type, type_topliv, id FROM completions where fullgeneration_id = %s AND type_topliv = %s" % (fullgeneration_id, type_topliv)) row = cursor.fetchone() compl_id = row[3] if is_first_car: deleted_compl_rus = cursor.execute("delete from compl_rus where compl_id = %s" % compl_id) for param, row_id in params: sql = u"INSERT INTO compl_rus (compl_id, modification, groupparam, param, paramvalue) VALUES (%s, '%s', '%s', '%s', %s)" % (compl_id, col[NUM_ROW_MODIFICATION].value, param[0], param[1], col[row_id].value) inserted_compl_rus += cursor.execute(sql) is_first_car = False db.rollback() print '\nSTATISTICS:' print 'Inserted completion:', inserted_completion print 'Inserted compl_rus:', inserted_compl_rus print 'Deleted compl_rus:', deleted_compl_rus ans = raw_input('Commit changes? (y/n)') db.close() I has manually deleted records from table and than run script two times. See https://dpaste.de/MwMa . I think, that rollback in my code doesn't work. Why?

    Read the article

< Previous Page | 264 265 266 267 268 269 270 271 272 273 274 275  | Next Page >