Search Results

Search found 7127 results on 286 pages for 'calculated columns'.

Page 258/286 | < Previous Page | 254 255 256 257 258 259 260 261 262 263 264 265  | Next Page >

• SSIS Expressions - EvaluateAsExpression Problem

  - by Randy Minder

  In a Data Flow, I have an Derived Column task. In the expression for one of the columns, I have the following expression: [siteid] == "100" ? "1101" : [siteid] == "110" ? "1001" : [siteid] == "120" ? "2101" : [siteid] == "140" ? "1102" : [siteid] == "210" ? "2001" : [siteid] == "310" ? "3001" : [siteid] This works just fine. However, I intend to reuse this in at least a dozen other places so I want to store this to a variable and use the variable in the Derived Column instead of the hard-coded expression. When I attempt to create a variable, using the expression above, I get a syntax error saying 'siteid' is not defined. I guess this makes sense because it isn't. But how can I get this the expression to work by using a variable? It seems like I need some sort of way to tell it that 'siteid' will be the column containing the data I want to apply the expression to.

  Read the article

• getting string.substring(N) not to choke when N > string.length

  - by aape

  I'm writing some code that takes a report from the mainframe and converts it to a spreadsheet. They can't edit the code on the MF to give me a delimited file, so I'm stuck dealing with it as fixed width. It's working okay now, but I need to get it more stable before I release it for testing. My problem is that in any given line of data, say it could have three columns of numbers, each five chars wide at positions 10, 16, and 22. If on this one particular row, there's no data for the last two cols, it won't be padded with spaces; rather, the length of the string will be only 14. So, I can't just blindly have dim s as string = someStream.readline a = s.substring(10, 5) b = s.substring(16, 5) c = s.substring(22, 5) because it'll choke when it substrings past the length of the string. I know I could test the length of the string before processing each row, and I have automated the filling of some of the vsariables using a counter and a loop, and using the counter*theWidthOfTheGivenVariable to jump around, but this project was a dog to start with (come on! turning a report into a spreadsheet?), but there are many different types of rows (it's not just a grid), and the code's getting ugly fast. I'd like this to be clean, clear, and maintainable for the poor sucker that gets this after me. If it matters, here's my code so far (it's really crufty at the moment). You can see some of my/its idiocy in the processSection#data subs So, I'm wondering 1) is there a way baked in to .NET to have string.substring not error when reading past the end of a string without wrapping it in a try...catch? and 2) would it be appropriate in this situation to write a new string class that inherits from string that has a more friendly substring function in it? ETA: Thanks for all the advice and knowledge everyone. I'll go with the extension. Hopefully one of these years, I'll get my chops up enough to pay someone back in kind. :)

  Read the article

• Optimized 2D Tile Scrolling in OpenGL

  - by silicus

  Hello, I'm developing a 2D sidescrolling game and I need to optimize my tiling code to get a better frame rate. As of right now I'm using a texture atlas and 16x16 tiles for 480x320 screen resolution. The level scrolls in both directions, and is significantly larger than 1 screen (thousands of pixels). I use glTranslate for the actual scrolling. So far I've tried: Drawing only the on-screen tiles using glTriangles, 2 per square tile (too much overhead) Drawing the entire map as a Display List (great on a small level, way to slow on a large one) Partitioning the map into Display Lists half the size of the screen, then culling display lists (still slows down for 2-directional scrolling, overdraw is not efficient) Any advice is appreciated, but in particular I'm wondering: I've seen Vertex Arrays/VBOs suggested for this because they're dynamic. What's the best way to take advantage of this? If I simply keep 1 screen of vertices plus a bit of overdraw, I'd have to recopy the array every few frames to account for the change in relative coordinates (shift everything over and add the new rows/columns). If I use more overdraw this doesn't seem like a big win; it's like the half-screen display list idea. Does glScissor give any gain if used on a bunch of small tiles like this, be it a display list or a vertex array/VBO Would it be better just to build the level out of large textures and then use glScissor? Would losing the memory saving of tiling be an issue for mobile development if I do this (just curious, I'm currently on a PC)? This approach was mentioned here Thanks :)

  Read the article

• iPhone and iPad : Doing a "select * from something" query in a SQLite database

  - by Abramodj

  Hi folks, i'm trying to use the SQLite data base in my iPad app, and here's my function to make a query: - (void)executeQuery:(char*)query { NSString *file = [self getWritableDBPath]; NSFileManager *fileManager = [NSFileManager defaultManager]; BOOL success = [fileManager fileExistsAtPath:file]; // If its not a local copy set it to the bundle copy if(!success) { //file = [[NSBundle mainBundle] pathForResource:DATABASE_TITLE ofType:@"db"]; [self createEditableCopyOfDatabaseIfNeeded]; } dataArray = NULL; dataArray = [NSMutableArray array]; sqlite3 *database = NULL; if (sqlite3_open([file UTF8String], &database) == SQLITE_OK) { sqlite3_exec(database, query, loadTimesCallback, dataArray, NULL); } sqlite3_close(database); [self logResults]; } if I call [self executeQuery:"select name from table1"]; everything is working fine. But if i call [self executeQuery:"select * from cars"]; the app crashes telling me that the NSMutableArray dataArray is not the right kind of variable where to set the query results. So, how can i do a "select * form table1" query, and store the results? Thanks! EDIT: Here's my loadTimesCallback method: static int loadTimesCallback(void *context, int count, char **values, char **columns) { NSMutableArray *times = (NSMutableArray *)context; for (int i=0; i < count; i++) { const char *nameCString = values[i]; [times addObject:[NSString stringWithUTF8String:nameCString]]; } return SQLITE_OK; }

  Read the article

• GridView edit problem If primary key is editable (design problem)

  - by Nassign

  I would like to ask about the design of table based on it's editability in a Grid View. Let me explain. For example, I have a table named ProductCustomerRel. Method 1 CustomerCode varchar PK ProductCode varchar PK StoreCode varchar PK Quantity int Note text So the combination of the CustomerCode, StoreCode and ProductCode must be unique. The record is displayed on a gridview. The requirement is that you can edit the customer, product and storecode but when the data is saved, the PK constraint must still persist. The problem here is it would be natural for a grid to be able to edit the 3 primary key, you can only achieve the update operation of the grid view by first deleting the row and then inserting the row with the updated data. An alternative to this is to just update the table and add a SeqNo, and just enforce the unique constraint of the 3 columns when inserting and updating in the grid view. Method 2 SeqNo int PK CustomerCode varchar ProductCode varchar StoreCode varchar Quantity int Note text My question is which of the two method is better? or is there another way to do this?

  Read the article

• For-Loop and LINQ's deferred execution don't play well together

  - by Tim Schmelter

  The title suggests that i've already an idea what's going on, but i cannot explain it. I've tried to order a List<string[]> dynamically by each "column", beginning with the first and ending with the minimum Length of all arrays. So in this sample it is 2, because the last string[] has only two elements: List<string[]> someValues = new List<string[]>(); someValues.Add(new[] { "c", "3", "b" }); someValues.Add(new[] { "a", "1", "d" }); someValues.Add(new[] { "d", "4", "a" }); someValues.Add(new[] { "b", "2" }); Now i've tried to order all by the first and second column. I could do it statically in this way: someValues = someValues .OrderBy(t => t[0]) .ThenBy(t => t[1]) .ToList(); But if i don't know the number of "columns" i could use this loop(that's what I thought): int minDim = someValues.Min(t => t.GetLength(0)); // 2 IOrderedEnumerable<string[]> orderedValues = someValues.OrderBy(t => t[0]); for (int i = 1; i < minDim; i++) { orderedValues = orderedValues.ThenBy(t => t[i]); } someValues = orderedValues.ToList(); // IndexOutOfRangeException But that doesn't work, it fails with an IndexOutOfRangeException at the last line. The debugger tells me that i is 2 at that time, so the for-loop condition seems to be ignored, i is already == minDim. Why is that so?

  Read the article

• What is the best way to lay out elements in GWT?

  - by KutaBeach

  What is the best practice to specify the positions of elements in GWT widget? Imagine you have a task: place a set of widgets in page layout. What would you use to position all your buttons and inputs in some order? standart HTML markup with tables/divs + CSS styles for positioning GWT widgets: panels, grids, tables + CSS styles for positioning GWT widgets: panels, grids, tables + their native properties for positioning If 2 or 3 - what would you use to reproduce a standart HTML table with colspans, fixed width columns and paddings? ps UIBinder and XML markup. GWT 2.4 My opinion: one of the biggest advantages of GWT is the ability to prevent programmer from writing HTML markup and add cross-browser support for interfaces. We shouldn't drop these points so its better to choose p.3 and try to use CSS ONLY for decoration - i.e. colors, fonts etc. Another point of view: its a bad idea to place any styles inline. By specifying properties of the widgets in XML markup we are literally doing exactly this. Also, GWT doesn't have enough widgets to produce a normal layout. For example you need to create a simple table with collspans and fixed column width. How would you go about this? Looks like you have to embed several HorizontalPanels into VerticalPanels, specify width/height in everyone of them and produce a great paper of XML by this. So whats your opinion?

  Read the article

• Database/Object Mapping

  - by Eric

  Hello everyone, This is a beginner question, but it's been frustrating me... I am using C#, by the way. I'd like to make a few classes, each with their own properties and methods. I would also like to have a database to store certain instances of these classes in case I would ever need to look at them again. So, for example... class Polygon { String name; Double perimiter; int numSides; public Double GetArea() { // ... } } class Circle { String name; Double radius; public void PrintName() { // ... } } Say I've got these classes. I also want a database that has the TABLES "Polygon" and "Circle" with the COLUMNS "name" "perimeter" "radius" etc. And I want an easy way to save a class instance into the database, or pull a class instance out of the database. I have previously been using MS Access for my database stuff, which I don't mind using, but I would prefer if nothing other than .NET need to be installed. I've been researching online a bit, but I wanted to get some opinions on here. I have looked at Linq-to-Sql, but it seems you need Sql-Server. Is this true? If so, I'd really rather not use it because I don't want to have to have it installed everywhere. Anway, I'm just fishing for some ideas/insights/suggestions/etc. so please help me out if you can. Thanks.

  Read the article

• append text to lines in a CSV file

  - by MichaelMcCabe

  This question seems to have been asked a million times around the web, but I cannot find an answer which will work for me. Basically, I have a CSV file which has a number of columns (say two). The program goes through each row in the CSV file, taking the first column value, then asks the user for the value to be placed in the second column. This is done on a handheld running Windows 6. I am developing using C#. It seems a simple thing to do. But I cant seem to add text to a line. I cant use OleDb, as System.Data.Oledb isnt in the .Net version I am using. I could use another CSV file, and when they complete each line, it writes it to another CSV file. But the problems with that are - The file thats produced at the end needs to contain EVERY line (so what if they pull the batterys out half way). And what if they go back, to continue doing this another time, how will the program know where to start back from.

  Read the article

• In Excel 2010, how can I show a count of occurrences on a specific date within multiple time ranges?

  - by Justin

  Here's what I'm trying to do. I have three columns of data. ID, Date(MM/DD/YY), Time(00:00). I need to create a chart or table that shows the number of occurrences on, say, 12/10/2010 between 00:00 and 00:59, 1:00 and 1:59, etc, for each hour of the day. I can do countif and get results for the date, but I cannot figure out how to show a summary of the count of occurrences per hour for the 24 hour period. I have months of data and many times each day. Example of data set is below. Any help is greatly ID Date Time 221 12/10/2010 00:01 223 12/10/2010 00:45 227 12/10/2010 01:13 334 12/11/2010 14:45 I would like the results to read: Date Time Count 12/10/2010 00:00AM - 00:59AM 2 12/10/2010 01:00AM - 01:59AM 1 12/10/2010 02:00AM - 02:59AM 0 ......(continues for every hour of the day) 12/11/2010 00:00AM - 00:59AM 0 ......... 12/11/2010 14:00PM - 14:59PM 1 And so on. Sorry for the length but I wanted to be clear. EDIT Here is a sample spreadsheet. Very little data, but I couldn't figure out a better way without having a huge file. Tested in notepad for formatting and worked ok on import as csv. PID,Date,Time 2888759,12/10/2010,0:10 2888760,12/10/2010,0:10 2888761,12/10/2010,0:10 2888762,12/10/2010,0:11 2889078,12/10/2010,15:45 2889079,12/10/2010,15:57 2889080,12/10/2010,15:57 2889081,12/10/2010,15:58 2889082,12/10/2010,16:10 2889083,12/10/2010,16:11 2889084,12/10/2010,16:11 2889085,12/10/2010,16:12 2889086,12/10/2010,16:12 2889087,12/10/2010,16:12 2889088,12/10/2010,16:13 2891529,12/14/2010,16:21

  Read the article

• LINQ to SQL - database relationships won't update after submit

  - by Quantic Programming

  I have a Database with the tables Users and Uploads. The important columns are: Users -> UserID Uploads -> UploadID, UserID The primary key in the relationship is Users -> UserID and the foreign key is Uploads -> UserID. In LINQ to SQL, I do the following operations: Retrieve files var upload = new Upload(); upload.UserID = user.UserID; upload.UploadID = XXX; db.Uploads.InsertOnSubmit(upload) db.SubmitChanges(); If I do that and rerun the application (and the db object is re-built, of course) - if do something like this: foreach(var upload in user.Uploads) I get all the uploads with that user's ID. (like added in the previous example) The problem is, that my application, after adding an upload an submitting changes, doesn't update the user.Uploads collection. i.e - I don't get the newly added uploads. The user object is stored in the Session object. At first, I though that the LINQ to SQL Framework doesn't update the reference of the object, therefore I should simply "reset" the user object from a new SQL request. I mean this: Session["user"] = db.Users.Where(u => u.UserID == user.UserID).SingleOrDefault(); (Where user is the previous user) But it didn't help. Please note: After rerunning the application, user.Uploads does have the new upload! Did anyone experience this type of problem, or is it normal behavior? I am a newbie to this framework. I would gladly take any advice. Thank you!

  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

• Vectorize matrix operation in R

  - by Fernando

  I have a R x C matrix filled to the k-th row and empty below this row. What i need to do is to fill the remaining rows. In order to do this, i have a function that takes 2 entire rows as arguments, do some calculations and output 2 fresh rows (these outputs will fill the matrix). I have a list of all 'pairs' of rows to be processed, but my for loop is not helping performance: # M is the matrix # nrow(M) and k are even, so nLeft is even M = matrix(1:48, ncol = 3) # half to fill k = nrow(M)/2 # simulate empty rows to be filled M[-(1:k), ] = 0 cat('before fill') print(M) # number of empty rows to fill nLeft = nrow(M) - k nextRow = k + 1 # list of rows to process (could be any order of non-empty rows) idxList = matrix(1:k, ncol = 2) for ( i in 1 : (nLeft / 2)) { row1 = M[idxList[i, 1],] row2 = M[idxList[i, 2],] # the two columns in 'results' will become 2 rows in M # fake result, return 2*row1 and 3*row2 results = matrix(c(2*row1, 3*row2), ncol = 2) # fill the matrix M[nextRow, ] = results[, 1] nextRow = nextRow + 1 M[nextRow, ] = results[, 2] nextRow = nextRow + 1 } cat('after fill') print(M) I tried to vectorize this, but failed... appreciate any help on improving this code, thanks!

  Read the article

• Symfony 2 - Updating a table based on newly inserted record in another table

  - by W00d5t0ck

  I'm trying to create a small forum application using Symfony 2 and Doctrine 2. My ForumTopic entity has a last_post field (oneToOne mapping). Now when I persist my new post with $em->persist($post); I want to update my ForumTopic entity so its last_post field would reference this new post. I have just realised that it cannot be done with a Doctrine postPersist Listener, so I decided to use a small hack, and tried: $em->persist($post); $em->flush(); $topic->setLastPost($post); $em->persist($post); $em->flush(); but it doesn't seem to update my topics table. I also took a look at http://docs.doctrine-project.org/projects/doctrine-orm/en/2.1/reference/working-with-associations.html#transitive-persistence-cascade-operations hoping it will solve the problem by adding cascade: [ 'persist' ] to my Topic.orm.yml file, but it didn't help, either. Could anyone point me to a solution or an example class? My ForumTopic is: FrontBundle\Entity\ForumTopic: type: entity table: forum_topics id: id: type: integer generator: strategy: AUTO fields: title: type: string(100) nullable: false slug: type: string(100) nullable: false created_at: type: datetime nullable: false updated_at: type: datetime nullable: true update_reason: type: text nullable: true oneToMany: posts: targetEntity: ForumPost mappedBy: topic manyToOne: created_by: targetEntity: User inversedBy: articles nullable: false updated_by: targetEntity: User nullable: true default: null topic_group: targetEntity: ForumTopicGroup inversedBy: topics nullable: false oneToOne: last_post: targetEntity: ForumPost nullable: true default: null cascade: [ persist ] uniqueConstraint: uniqueSlugByGroup: columns: [ topic_group, slug ] And my ForumPost is: FrontBundle\Entity\ForumPost: type: entity table: forum_posts id: id: type: integer generator: strategy: AUTO fields: created_at: type: datetime nullable: false updated_at: type: datetime nullable: true update_reason: type: string nullable: true text: type: text nullable: false manyToOne: created_by: targetEntity: User inversedBy: forum_posts nullable: false updated_by: targetEntity: User nullable: true default: null topic: targetEntity: ForumTopic inversedBy: posts

  Read the article

• Which is faster: Appropriate data input or appropriate data structure?

  - by Anon

  I have a dataset whose columns look like this: Consumer ID | Product ID | Time Period | Product Score 1 | 1 | 1 | 2 2 | 1 | 2 | 3 and so on. As part of a program (written in C) I need to process the product scores given by all consumers for a particular product and time period combination for all possible combinations. Suppose that there are 3 products and 2 time periods. Then I need to process the product scores for all possible combinations as shown below: Product ID | Time Period 1 | 1 1 | 2 2 | 1 2 | 2 3 | 1 3 | 2 I will need to process the data along the above lines lots of times ( 10k) and the dataset is fairly large (e.g., 48k consumers, 100 products, 24 time periods etc). So speed is an issue. I came up with two ways to process the data and am wondering which is the faster approach or perhaps it does not matter much? (speed matters but not at the cost of undue maintenance/readability): Sort the data on product id and time period and then loop through the data to extract data for all possible combinations. Store the consumer ids of all consumers who provided product scores for a particular combination of product id and time period and process the data accordingly. Any thoughts? Any other way to speed up the processing? Thanks

  Read the article

• Java: Inputting text from a file using split

  - by 00PS

  I am inputting an adjacency list for a graph. There are three columns of data (vertex, destination, edge) separated by a single space. Here is my implementation so far: FileStream in = new FileStream("input1.txt"); Scanner s = new Scanner(in); String buffer; String [] line = null; while (s.hasNext()) { buffer = s.nextLine(); line = buffer.split("\\s+"); g.add(line[0]); System.out.println("Added vertex " + line[0] + "."); g.addEdge(line[0], line[1], Integer.parseInt(line[2])); System.out.println("Added edge from " + line[0] + " to " + line[1] + " with a weight of " + Integer.parseInt(line[2]) + "."); } System.out.println("Size of graph = " + g.size()); Here is the output: Added vertex a. Added edge from a to b with a weight of 9. Exception in thread "main" java.lang.NullPointerException at structure5.GraphListDirected.addEdge(GraphListDirected.java:93) at Driver.main(Driver.java:28) I was under the impression that line = buffer.split("\\s+"); would return a 2 dimensional array of Strings to the variable line. It seemed to work the first time but not the second. Any thoughts? I would also like some feedback on my implementation of this problem. Is there a better way? Anything to help out a novice! :)

  Read the article

• load data from grid row into (pop up) form for editing

  - by user1495457

  I read in Ext JS in Action ( by J. Garcia) that if we have an instance of Ext.data.Record, we can use the form's loadRecord method to set the form's values. However, he does not give a working example of this (in the example that he uses data is loaded into a form through a file called data.php). I have searched many forums and found the following entry helpful as it gave me an idea on how to solve my problem by using form's loadRecord method: load data from grid to form Now the code for my store and grid is as follows: var userstore = Ext.create('Ext.data.Store', { storeId: 'viewUsersStore', model: 'Configs', autoLoad: true, proxy: { type: 'ajax', url: '/user/getuserviewdata.castle', reader: { type: 'json', root: 'users' }, listeners: { exception: function (proxy, response, operation, eOpts) { Ext.MessageBox.alert("Error", "Session has timed-out. Please re-login and try again."); } } } }); var grid = Ext.create('Ext.grid.Panel', { id: 'viewUsersGrid', title: 'List of all users', store: Ext.data.StoreManager.lookup('viewUsersStore'), columns: [ { header: 'Username', dataIndex: 'username' }, { header: 'Full Name', dataIndex: 'fullName' }, { header: 'Company', dataIndex: 'companyName' }, { header: 'Latest Time Login', dataIndex: 'lastLogin' }, { header: 'Current Status', dataIndex: 'status' }, { header: 'Edit', menuDisabled: true, sortable: false, xtype: 'actioncolumn', width: 50, items: [{ icon: '../../../Content/ext/img/icons/fam/user_edit.png', tooltip: 'Edit user', handler: function (grid, rowIndex, colIndex) { var rec = userstore.getAt(rowIndex); alert("Edit " + rec.get('username')+ "?"); EditUser(rec.get('id')); } }] }, ] }); function EditUser(id) { //I think I need to have this code here - I don't think it's complete/correct though var formpanel = Ext.getCmp('CreateUserForm'); formpanel.getForm().loadRecord(rec); } 'CreateUserForm' is the ID of a form that already exists and which should appear when user clicks on Edit icon. That pop-up form should then automatically be populated with the correct data from the grid row. However my code is not working. I get an error at the line 'formpanel.getForm().loadRecord(rec)' - it says 'Microsoft JScript runtime error: 'undefined' is null or not an object'. Any tips on how to solve this?

  Read the article

• sql queries slower than expected

  - by neubert

  Before I show the query here are the relevant table definitions: CREATE TABLE phpbb_posts ( topic_id mediumint(8) UNSIGNED DEFAULT '0' NOT NULL, poster_id mediumint(8) UNSIGNED DEFAULT '0' NOT NULL, KEY topic_id (topic_id), KEY poster_id (poster_id), ); CREATE TABLE phpbb_topics ( topic_id mediumint(8) UNSIGNED NOT NULL auto_increment ); Here's the query I'm trying to do: SELECT p.topic_id, p.poster_id FROM phpbb_topics AS t LEFT JOIN phpbb_posts AS p ON p.topic_id = t.topic_id AND p.poster_id <> ... WHERE p.poster_id IS NULL; Basically, the query is an attempt to find all topics where the number of times someone other than the target user has posted in is zero. In other words, the topics where the only person who has posted is the target user. Problem is that query is taking a super long time. My general assumption when it comes to SQL is that JOINs of any are super fast and can be done in no time at all assuming all relevant columns are primary or foreign keys (which in this case they are). I tried out a few other queries: SELECT COUNT(1) FROM phpbb_topics AS t JOIN phpbb_posts AS p ON p.topic_id = t.topic_id; That returns 353340 pretty quickly. I then do these: SELECT COUNT(1) FROM phpbb_topics AS t JOIN phpbb_posts AS p ON p.topic_id = t.topic_id AND p.poster_id <> 77198; SELECT COUNT(1) FROM phpbb_topics AS t JOIN phpbb_posts AS p ON p.topic_id = t.topic_id WHERE p.poster_id <> 77198; And both of those take quite a while (between 15-30 seconds). If I change the < to a = it takes no time at all. Am I making some incorrect assumptions? Maybe my DB is just foobar'd?

  Read the article

• How do I select column(s) by their "numeric" position in a table?

  - by DulcimerDude

  I am trying to select columns by their "x" position in the table. DBI my $example = $hookup->prepare(qq{SELECT This,That,Condition,"I also want COLUMN-10" FROM tbl LIMIT ? ?}); ###column_number=10 ordinal_position?? $example->execute('2','10') or die "Did not execute"; Is this possible or do I need to run another single select to just that column? One problem I encountered was with a col named "Condition". For some reason, when I tried to select Condition the execute would die. I never attempted but, What if the column name was SELECT? Another note is the table is 75 cols wide and I only need 50 of them. The Col names are pretty verbose so, I would like to just call them by their "position". This would also allow the col names to be changed in the future without having to change the select statement. I am quite the newbie so please explain any answers down to my level. Thanks for any assistance..

  Read the article

• Layout question with BlackBerry IDE FieldManagers; how to emulate HTML's rowspan

  - by canadiancreed

  Hello all I'm trying to create a page where a list of items are displayed in a row where there are multiple columns on the left, but only one on the right, encased within a horizontialFieldManager. Currently I have the following code to attempt to do the following: VerticalFieldManager mainScreenManager = new VerticalFieldManager(); mainScreenManager.add(titleField); for (int i = 0; i < 10; i++) { HorizontalFieldManager itemAreaManager = new HorizontalFieldManager(); VerticalFieldManager itemTextFieldsAreaManager = new VerticalFieldManager(); itemTextFieldsAreaManager.add(new RichTextField(contentArticleTitle[i])); itemTextFieldsAreaManager.add(new RichTextField(contentArticleDate[i])); itemTextFieldsAreaManager.add(new SeparatorField()); itemAreaManager.add(itemTextFieldsAreaManager); itemAreaManager.add(new ButtonField("", 0)); mainScreenManager.add(itemAreaManager); }; add(mainScreenManager); Now the issue I'm experiencing is probably obvious to those familiar with managers; the horizontialFieldManager has the first item added to it consuming the entire width available, thereby never showing the button. What I'm wondering is how can I tell this in an extended class to only take up a certain percentage of the available width? I've tried subLayout and setting the width to be a certain amount, but it will just show the button instead of the text (pretty much same problem, just reversed)

  Read the article

• Why use shorter VARCHAR(n) fields?

  - by chryss

  It is frequently advised to choose database field sizes to be as narrow as possible. I am wondering to what degree this applies to SQL Server 2005 VARCHAR columns: Storing 10-letter English words in a VARCHAR(255) field will not take up more storage than in a VARCHAR(10) field. Are there other reasons to restrict the size of VARCHAR fields to stick as closely as possible to the size of the data? I'm thinking of Performance: Is there an advantage to using a smaller n when selecting, filtering and sorting on the data? Memory, including on the application side (C++)? Style/validation: How important do you consider restricting colunm size to force non-sensical data imports to fail (such as 200-character surnames)? Anything else? Background: I help data integrators with the design of data flows into a database-backed system. They have to use an API that restricts their choice of data types. For character data, only VARCHAR(n) with n <= 255 is available; CHAR, NCHAR, NVARCHAR and TEXT are not. We're trying to lay down some "good practices" rules, and the question has come up if there is a real detriment to using VARCHAR(255) even for data where real maximum sizes will never exceed 30 bytes or so. Typical data volumes for one table are 1-10 Mio records with up to 150 attributes. Query performance (SELECT, with frequently extensive WHERE clauses) and application-side retrieval performance are paramount.

  Read the article

• Apache POI rows number

  - by sys_debug

  I am using Apache POI java and want to get the total number of rows which are not empty. I successfully processed a whole row with all its columns. Now I am assuming that I get an excel sheet with multiple rows and not a single row...so how to go about that? I was thinking of getting total number of rows (int n) and then loop until i<=n but not sure. Suggestions are most welcome :) Note: Apache POI version is 3.8. I am not dealing with Xlsx format...only xls. Yes I tried this code but got 20 in return....which is not possible given I have only 5 rows FileInputStream fileInputStream = new FileInputStream("COD.xls"); HSSFWorkbook workbook = new HSSFWorkbook(fileInputStream); HSSFSheet worksheet = workbook.getSheet("COD"); HSSFRow row1 = worksheet.getRow(3); Iterator rows = worksheet.rowIterator(); int noOfRows = 0; while( rows.hasNext() ) { HSSFRow row = (HSSFRow) rows.next(); noOfRows++; } System.out.println("Number of Rows: " + noOfRows);

  Read the article

• Parallelize or vectorize all-against-all operation on a large number of matrices?

  - by reve_etrange

  I have approximately 5,000 matrices with the same number of rows and varying numbers of columns (20 x ~200). Each of these matrices must be compared against every other in a dynamic programming algorithm. In this question, I asked how to perform the comparison quickly and was given an excellent answer involving a 2D convolution. Serially, iteratively applying that method, like so list = who('data_matrix_prefix*') H = cell(numel(list),numel(list)); for i=1:numel(list) for j=1:numel(list) if i ~= j eval([ 'H{i,j} = compare(' char(list(i)) ',' char(list(j)) ');']); end end end is fast for small subsets of the data (e.g. for 9 matrices, 9*9 - 9 = 72 calls are made in ~1 s). However, operating on all the data requires almost 25 million calls. I have also tried using deal() to make a cell array composed entirely of the next element in data, so I could use cellfun() in a single loop: # who(), load() and struct2cell() calls place k data matrices in a 1D cell array called data. nextData = cell(k,1); for i=1:k [nextData{:}] = deal(data{i}); H{:,i} = cellfun(@compare,data,nextData,'UniformOutput',false); end Unfortunately, this is not really any faster, because all the time is in compare(). Both of these code examples seem ill-suited for parallelization. I'm having trouble figuring out how to make my variables sliced. compare() is totally vectorized; it uses matrix multiplication and conv2() exclusively (I am under the impression that all of these operations, including the cellfun(), should be multithreaded in MATLAB?). Does anyone see a (explicitly) parallelized solution or better vectorization of the problem?

  Read the article

• Subitems are not all added to a list view in C# using XmlNodeList

  - by tim

  I'm working on extracting data from an RSS feed. In my listview (rowNews), I've got two columns: Title and URL. When the button is clicked, all of the titles of the articles are showing up in the title column, but only one URL is added to the URL column. I switched them around so that the URLs would be added to the first column and all of the correct URLs appeared... leading me to think this is a problem with my listview source (it's my first time working with subitems). Here's the original, before I started experimenting with the order: private void button1_Click(object sender, EventArgs e) { XmlTextReader rssReader = new XmlTextReader(txtUrl.Text); XmlDocument rssDoc = new XmlDocument(); rssDoc.Load(rssReader); XmlNodeList titleList = rssDoc.GetElementsByTagName("title"); XmlNodeList urlList = rssDoc.GetElementsByTagName("link"); ListViewItem lvi = new ListViewItem(); for (int i = 0; i < titleList.Count; i++) { rowNews.Items.Add(titleList[i].InnerXml); } for (int i = 0; i < urlList.Count; i++) { lvi.SubItems.Add(urlList[i].InnerXml); } rowNews.Items.Add(lvi); }

  Read the article

• database design - empty fields

  - by imanc

  Hey, I am currently debating an issue with a guy on my dev team. He believes that empty fields are bad news. For instance, if we have a customer details table that stores data for customers from different countries, and each country has a slightly different address configuration - plus 1-2 extra fields, e.g. French customer details may also store details for entry code, and floor/level plus title fields (madamme, etc.). South Africa would have a security number. And so on. Given that we're talking about minor variances my idea is to put all of the fields into the table and use what is needed on each form. My colleague believes we should have a separate table with extra data. E.g. customer_info_fr. But this seams to totally defeat the purpose of a combined table in the first place. His argument is that empty fields / columns is bad - but I'm struggling to find justification in terms of database design principles for or against this argument and preferred solutions. Another option is a separate mini EAV table that stores extra data with parent_id, key, val fields. Or to serialise extra data into an extra_data column in the main customer_data table. I think I am confused because what I'm discussing is not covered by 3NF which is what I would typically use as a reference for how to structure data. So my question specifically: - if you have slight variances in data for each record (1-2 different fields for instance) what is the best way to proceed?

  Read the article

< Previous Page | 254 255 256 257 258 259 260 261 262 263 264 265  | Next Page >