Search Results

Search found 5380 results on 216 pages for 'primary'.

Page 177/216 | < Previous Page | 173 174 175 176 177 178 179 180 181 182 183 184  | Next Page >

  • Increment non unique field during SQL insert

    - by phill
    I'm not sure how to word this cause I am a little confused at the moment, so bare with me while I attempt to explain, I have a table with the following fields: OrderLineID, OrderID, OrderLine, and a few other unimportant ones. OrderLineID is the primary key and is always unique(which isn't a problem), OrderID is a foreign key that isn't unique(also not a problem), and OrderLine is a value that is not unique in the table, but should be unique for any OrderIDs that are the same...so if that didn't make sense, perhaps a picture OrderLineID, OrderID, OrderLine 1 1 1 2 1 2 3 1 3 4 2 1 5 2 2 For all OrderIDs there is a unique OrderLine. I am trying to create an insert statement that gets the max OrderLine value for a specific OrderId so I can increment it, but it's not working so well and I could use a little help. What I have right now is below, I build the sql statement in a program and replace OrderID # with an actual value. I am pretty sure the problem is with the nested select statement, and incrementing the result, but I can't find any examples that do this since my google skills are weak apparently.... INSERT INTO tblOrderLine (OrderID, OrderLine) VALUES (<OrderID #>, (SELECT MAX(OrderLine) FROM tblOrderLine WHERE orderID = <same OrderID #>)+1) any help would be nice.

    Read the article

  • DataTable throwing exception on RejectChanges

    - by Vale
    I found this bug while working with a DataTable. I added a primary key column to a DataTable, than added one row to that table, removed that row, and added row with the same key to the table. This works. When I tried to call RejectChanges() on it, I got ConstraintException saying that value is already present. Here is the example: var dataTable = new DataTable(); var column = new DataColumn("ID", typeof(decimal)); dataTable.Columns.Add(column); dataTable.PrimaryKey = new [] {column }; decimal id = 1; var oldRow = dataTable.NewRow(); oldRow[column] = id; dataTable.Rows.Add(oldRow); dataTable.AcceptChanges(); oldRow.Delete(); var newRow = dataTable.NewRow(); newRow[column] = id; dataTable.Rows.Add(newRow); dataTable.RejectChanges(); // This is where it crashes I think since the row is deleted, exception should not be thrown (constraint is not violated because row is in deleted state). Is there something I can do about this? Any help is appreciated.

    Read the article

  • PostgreSQL, Foreign Keys, Insert speed & Django

    - by Miles
    A few days ago, I ran into an unexpected performance problem with a pretty standard Django setup. For an upcoming feature, we have to regenerate a table hourly, containing about 100k rows of data, 9M on the disk, 10M indexes according to pgAdmin. The problem is that inserting them by whatever method literally takes ages, up to 3 minutes of 100% disk busy time. That's not something you want on a production site. It doesn't matter if the inserts were in a transaction, issued via plain insert, multi-row insert, COPY FROM or even INSERT INTO t1 SELECT * FROM t2. After noticing this isn't Django's fault, I followed a trial and error route, and hey, the problem disappeared after dropping all foreign keys! Instead of 3 minutes, the INSERT INTO SELECT FROM took less than a second to execute, which isn't too surprising for a table <= 20M on the disk. What is weird is that PostgreSQL manages to slow down inserts by 180x just by using 3 foreign keys. Oh, disk activity was pure writing, as everything is cached in RAM; only writes go to the disks. It looks like PostgreSQL is working very hard to touch every row in the referred tables, as 3MB/sec * 180s is way more data than the 20MB this new table takes on disk. No WAL for the 180s case, I was testing in psql directly, in Django, add ~50% overhead for WAL logging. Tried @commit_on_success, same slowness, I had even implemented multi row insert and COPY FROM with psycopg2. That's another weird thing, how can 10M worth of inserts generate 10x 16M log segments? Table layout: id serial primary, a bunch of int32, 3 foreign keys to small table, 198 rows, 16k on disk large table, 1.2M rows, 59 data + 89 index MB on disk large table, 2.2M rows, 198 + 210MB So, am I doomed to either drop the foreign keys manually or use the table in a very un-Django way by defining saving bla_id x3 and skip using models.ForeignKey? I'd love to hear about some magical antidote / pg setting to fix this.

    Read the article

  • Which Table Should be Master and Child in Database Design

    - by Jason
    I am quickly learning the ins and outs of database design (something that, as of a week ago, was new to me), but I am running across some questions that don't seem immediately obvious, so I was hoping to get some clarification. The question I have right is about foreign keys. As part of my design, I have a Company table. Originally, I had included address information directly within the table, but, as I was hoping to achieve 3NF, I broke out the address information into its own table, Address. In order to maintain data integrity, I created a row in Company called "addressId" as an INT and the Address table has a corresponding addressId as its primary key. What I'm a little bit confused about (or what I want to make sure I'm doing correctly) is determining which table should be the master (referenced) table and which should be the child (referencing) table. When I originally set this up, I made the Address table the master and the Company the child. However, I now believe this is wrong due to the fact that there should be only one address per Company and, if a Company row is deleted, I would want the corresponding Address to be removed as well (CASCADE deletion). I may be approaching this completely wrong, so I would appreciate any good rules of thumb on how to best think about the relationship between tables when using foreign keys. Thanks!

    Read the article

  • Use Javascript RegEx to extract column names from SQLite Create Table SQL

    - by NimbusSoftware
    I'm trying to extract column names from a SQLite result set from sqlite_master's sql column. I get hosed up in the regular expressions in the match() and split() functions. t1.executeSql('SELECT name, sql FROM sqlite_master WHERE type="table" and name!="__WebKitDatabaseInfoTable__";', [], function(t1, result) { for(i = 0;i < result.rows.length; i++){ var tbl = result.rows.item(i).name; var dbSchema = result.rows.item(i).sql; // errors out on next line var columns = dbSchema.match(/.*CREATE\s+TABLE\s+(\S+)\s+\((.*)\).*/)[2].split(/\s+[^,]+,?\s*/); } }, function(){console.log('err1');} ); I want to parse SQL statements like these... CREATE TABLE sqlite_sequence(name,seq); CREATE TABLE tblConfig (Key TEXT NOT NULL,Value TEXT NOT NULL); CREATE TABLE tblIcon (IconID INTEGER NOT NULL PRIMARY KEY,png TEXT NOT NULL,img32 TEXT NOT NULL,img64 TEXT NOT NULL,Version TEXT NOT NULL) into a strings like theses... name,seq Key,Value IconID,png,img32,img64,Version Any help with a RegEx would be greatly appreciated.

    Read the article

  • SQL placeholder in WHERE IN issue, inserted strings fail.

    - by Alastair Pitts
    As part of my jobs, I need to writes SQL queries to connect to our PI database. To generate a query, I need to pass an array of tags (essentially primary keys), but these have to be inserted as strings. As this will be a modular query and used for multiple tags, a placeholder is being used. The query relies upon the use of the WHERE IN statement, which is where the placeholder is, like below: SELECT SUM(value * 5/1000) as "Hourly Flow [kL]" from piarchive..pitotal WHERE tag IN (?) AND time between ? and ? and timestep = '1d' and calcbasis = 'Eventweighted' and value <> '' The issue is the format in which the tags are to be passed in as. If I add them directly into the query (for testing), they go in the format (these are example numbers): '000000012','00000032','005050236','4560236' and the query looks like: SELECT SUM(value * 5/1000) as "Hourly Flow [kL]" from piarchive..pitotal WHERE tag IN ('000000012','00000032','005050236','4560236') AND time between ? and ? and timestep = '1d' and calcbasis = 'Eventweighted' and value <> '' which works. If I try and add the same tags into the placeholder, the query fails. If I only add 1 tag, with no quotes (using the placeholder), the query works. Why is this happening? Is there anyway around it?

    Read the article

  • Trying to convert existing production database table columns from enum to VARCHAR (Rails)

    - by dchua
    Hi everyone, I have a problem that needs me to convert my existing live production (I've duplicated the schema on my local development box, don't worry :)) table column types from enums to a string. Background: Basically, a previous developer left my codebase in absolute shit, migration versions are extremely out of date, and apparently he never used it after a certain point of time in development and now that I'm tasked with migrating a rails 1.2.6 app to 2.3.5, I can't get the tests to run properly on 2.3.5 because my table columns have ENUM column types and they convert to :string, :limit = 0 on my schema.rb which creates the problem of an invalid default value when doing a rake db:test:prepare, like in the case of: Mysql::Error: Invalid default value for 'own_vehicle': CREATE TABLE `lifestyles` (`id` int(11) DEFAULT NULL auto_increment PRIMARY KEY, `member_id` int(11) DEFAULT 0 NOT NULL, `own_vehicle` varchar(0) DEFAULT 'Y' NOT NULL, `hobbies` text, `sports` text, `AStar_activities` text, `how_know_IRC` varchar(100), `IRC_referral` varchar(200), `IRC_others` varchar(100), `IRC_rdrive` varchar(30)) ENGINE=InnoDB I'm thinking of writing a migration task that looks through all the database tables for columns with enum and replace it with VARCHAR and I'm wondering if this is the right way to approach this problem. I'm also not very sure how to write it such that it would loop through my database tables and replace all ENUM colum_types with a VARCHAR. References [1] https://rails.lighthouseapp.com/projects/8994/tickets/997-dbschemadump-saves-enum-columns-as-varchar0-on-mysql [2] http://dev.rubyonrails.org/ticket/2832

    Read the article

  • Deterministic and non uniform long string generation from seed

    - by Limonup
    I had this weird idea for an encryption that I wanted to try out, it may be bad, and it may have done before, but I'm just doing it for fun. The short version of the question is: Is it possible to generate a long, deterministic and non-uniformly distributed string/sequence of numbers from a small seed? Long(er) version: I was thinking to encrypt a text by changing encoding. The new encoding would be generated via Huffman algorithm. To work well, the Huffman algorithm would need a fairly long text with non uniform distribution. Then characters can have different bit-lengths which would be the primary strength of this encryption. The problem is that its impractical to enter in/remember a long text each time you want to decrypt the text. So I was wondering if it was possible to generate a text from password seed? It doesn't matter what the text is, as long as it has non uniform distribution of characters and that the exact same sequence can be recreated each time you give it the same seed. Preferably, are there any functions/extensions in Python that can do this? EDIT: To expand on the "strength" of varying bit length: if I have a string "test", ASCII values 116, 101, 115, 116, which gives bit values of 1110100 1100101 1110011 1110100 Then, say my Huffman algorithm generates encoding like t = 101 e = 1100111 s = 10001 The final string is 101 1100111 10001 101, if we encode this back to ASCII, we get 1011100 1111000 1101000, which is 3 entirely different characters. Obviously its impossible to perform any kind of frequency analysis or something like that on this.

    Read the article

  • How do I make the manifest available during a Maven/Surefire unittest run "mvn test" ?

    - by Ernst de Haan
    How do I make the manifest available during a Maven/Surefire unittest run "mvn test" ? I have an open-source project that I am converting from Ant to Maven, including its unit tests. Here's the project source repository with the Maven project: http://github.com/znerd/logdoc My question pertains to the primary module, called "base". This module has a unit test that tests the behaviour of the static method getVersion() in the class org.znerd.logdoc.Library. This method returns: Library.class.getPackage().getImplementationVersion() The getImplementationVersion() method returns a value of a setting in the manifest file. So far, so good. I have tested this in the past and it works well, as long as the manifest is indeed available on the classpath at the path META-INF/MANIFEST.MF (either on the file system or inside a JAR file). Now my challenge is that the manifest file is not available when I run the unit tests: mvn test Surefire runs the unit tests, but my unit test fails with a mesage indicating that Library.getVersion() returned null. When I want to check the JAR, I find that it has not even been generated. Maven/Surefire runs the unit tests against the classes, before the resources are added to the classpath. So can I either run the unit tests against the JAR (implicitly requiring the JAR to be generated first) or can I make sure the resources (including the manifest file) are generated/copied under target/classes before the unit tests are run? Note that I use Maven 2.2.0, Java 1.6.0_17 on Mac OS X 10.6.2, with JUnit 4.8.1.

    Read the article

  • Why i cant save a long text on my MySQL database?

    - by DomingoSL
    im trying to save to my data base a long text (about 2500 chars) input by my users using a web form and passed to the server using php. When i look in phpmyadmin, the text gets crop. How can i config my table in order to get the complete text? This is my table config: CREATE TABLE `extra_879` ( `id` bigint(20) NOT NULL auto_increment, `id_user` bigint(20) NOT NULL, `title` varchar(300) NOT NULL, `content` varchar(3000) NOT NULL, PRIMARY KEY (`id`), UNIQUE KEY `id_user` (`id_user`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=4 ; Take a look of the field content that have a limit of 3000 chars, but the texts always gets crop at 690 chars. Thanks for any help! EDIT: I found the problem but i dont know how to solve it. The query is getting crop always in the same char, an special char: ù EDIT 2: This is the cropped query: INSERT INTO extra_879 (id,id_user,title,content) VALUES (NULL,'1','Informazione Extra',' Riconoscimenti Laurea di ingegneria presa a le 22 anni e in il terso posto della promozione Diploma analista di sistemi ottenuto il rating massimo 20/20, primo posto della promozione. Borsa di Studio (offerta dal Ministero Esteri Italiano) vinta nel 2010 (Valutazione del territorio attraverso le nueve tecnologie) Pubblicazione di paper; Stima del RCS della nave CCGS radar sulla base dei risultati di H. Leong e H. Wilson. http://www.ing.uc.edu.vek-azozayalarchivospdf/PAPER-Sarmiento.pdf Tesi di laurea: PROGETTAZIONE E REALIZZAZIONE DI UN SIS-TEMA DI TELEMETRIA GSM PER IL CONTROLLO DELLO STATO DI TRANSITO VEICOLARE E CLIMA (ottenuto il punteggio pi') It gets crop just when the (ottenuto il punteggio più alto) phrase, just when ù appear... EDIT 3: I using jquery + ajax to send the query $.ajax({type: "POST", url: "handler.php", data: "e_text="+ $('#e_text').val() + "&e_title="+ $('#extra_title').val(),

    Read the article

  • Algorithm for optimally choosing actions to perform a task

    - by Jules
    There are two data types: tasks and actions. An action costs a certain time to complete, and a set of tasks this actions consists of. A task has a set of actions, and our job is to choose one of them. So: class Task { Set<Action> choices; } class Action { float time; Set<Task> dependencies; } For example the primary task could be "Get a house". The possible actions for this task: "Buy a house" or "Build a house". The action "Build a house" costs 10 hours and has the dependencies "Get bricks" and "Get cement", etcetera. The total time is the sum of all the times of the actions required to perform. We want to choose actions such that the total time is minimal. Note that the dependencies can be diamond shaped. For example "Get bricks" could require "Get a car" (to transport the bricks) and "Get cement" would also require a car. Even if you do "Get bricks" and "Get cement" you only have to count the time it takes to get a car once. Note also that the dependencies can be circular. For example "Money" - "Job" - "Car" - "Money". This is no problem for us, we simply select all of "Money", "Job" and "Car". The total time is simply the sum of the time of these 3 things. Mathematical description: Let actions be the chosen actions. valid(task) = ?action ? task.choices. (action ? actions ? ?tasks ? action.dependencies. valid(task)) time = sum {action.time | action ? actions} minimize time subject to valid(primaryTask)

    Read the article

  • How to make a wxFrame behave like a modal wxDialog object

    - by dagorym
    Is is possible to make a wxFrame object behave like a modal dialog box in that the window creating the wxFrame object stops execution until the wxFrame object exits? I'm working on a small game and have run into the following problem. I have a main program window that hosts the main application (strategic portion). Occasionally, I need to transfer control to a second window for resolution of part of the game (tactical portion). While in the second window, I want the processing in the first window to stop and wait for completion of the work being done in the second window. Normally a modal dialog would do the trick but I want the new window to have some functionality that I can't seem to get with a wxDialog, namely a status bar at the bottom and the ability to resize/maximize/minimize the window (this should be possible but doesn't work, see this question How to get the minimize and maximize buttons to appear on a wxDialog object). As an addition note, I want the second window's functionality needs to stay completely decoupled from the primary window as it will be spun off into a separate program eventually. Has anyone done this or have any suggestions?

    Read the article

  • How can I automatically generate sql update scripts when some data is updated ?

    - by Brann
    I'd like to automatically generate an update script each time a value is modified in my database. In other words, if a stored procedure, or a query, or whatever updates column a with value b in table c (which as a pk column (i,j...k), I want to generate this : update c set a=b where i=... and j=... and k=... and store it somewhere (for example as a raw string in a table). To complicate things, I want the script to be generated only if the update has been made by a specific user. Good news is that I've got a primary key defined for all my tables. I can see how to do this using a trigger, but I would need to generate specific triggers for each table, and to update them each and every-time my schema changes. I guess there are some built-in ways to do this as SQL server sometimes need to store this kind of things (while using transactional replication for example), but couldn't find anything so far ... any ideas ? I'm also interested in ways to automatically generate triggers (probably using triggers - meta triggers, huh? - since I will need to update triggers automatically when the schema change)

    Read the article

  • Mysql select - improve performance

    - by realshadow
    Hey, I am working on an e-shop which sells products only via loans. I display 10 products per page in any category, each product has 3 different price tags - 3 different loan types. Everything went pretty well during testing time, query execution time was perfect, but today when transfered the changes to the production server, the site "collapsed" in about 2 minutes. The query that is used to select loan types sometimes hangs for ~10 seconds and it happens frequently and thus it cant keep up and its hella slow. The table that is used to store the data has approximately 2 milion records and each select looks like this: SELECT * FROM products_loans WHERE KOD IN("X17/Q30-10", "X17/12", "X17/5-24") AND 369.27 BETWEEN CENA_OD AND CENA_DO; 3 loan types and the price that needs to be in range between CENA_OD and CENA_DO, thus 3 rows are returned. But since I need to display 10 products per page, I need to run it trough a modified select using OR, since I didnt find any other solution to this. I have asked about it here, but got no answer. As mentioned in the referencing post, this has to be done separately since there is no column that could be used in a join (except of course price and code, but that ended very, very badly). Here is the show create table, kod and CENA_OD/CENA_DO very indexed via INDEX. CREATE TABLE `products_loans` ( `KOEF_ID` bigint(20) NOT NULL, `KOD` varchar(30) NOT NULL, `AKONTACIA` int(11) NOT NULL, `POCET_SPLATOK` int(11) NOT NULL, `koeficient` decimal(10,2) NOT NULL default '0.00', `CENA_OD` decimal(10,2) default NULL, `CENA_DO` decimal(10,2) default NULL, `PREDAJNA_CENA` decimal(10,2) default NULL, `AKONTACIA_SUMA` decimal(10,2) default NULL, `TYP_VYHODY` varchar(4) default NULL, `stage` smallint(6) NOT NULL default '1', PRIMARY KEY (`KOEF_ID`), KEY `CENA_OD` (`CENA_OD`), KEY `CENA_DO` (`CENA_DO`), KEY `KOD` (`KOD`), KEY `stage` (`stage`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 And also selecting all loan types and later filtering them trough php doesnt work good, since each type has over 50k records and the select takes too much time as well... Any ides about improving the speed are appreciated.

    Read the article

  • Changing the indexing on existing table in SQL Server 2000

    - by Raj
    Guys, Here is the scenario: SQL Server 2000 (8.0.2055) Table currently has 478 million rows of data. The Primary Key column is an INT with IDENTITY. There is an Unique Constraint imposed on two other columns with a Non-Clustered Index. This is a vendor application and we are only responsible for maintaining the DB. Now the vendor has recommended doing the following "to improve performance" Drop the PK and Clustered Index Drop the non-clustered index on the two columns with the UNIQUE CONSTRAINT Recreate the PK, with a NON-CLUSTERED index Create a CLUSTERED index on the two columns with the UNIQUE CONSTRAINT I am not convinced that this is the right thing to do. I have a number of concerns. By dropping the PK and indexes, you will be creating a heap with 478 million rows of data. Then creating a CLUSTERED INDEX on two columns would be a really mammoth task. Would creating another table with the same structure and new indexing scheme and then copying the data over, dropping the old table and renaming the new one be a better approach? I am also not sure how the stored procs will react. Will they continue using the cached execution plan, considering that they are not being explicitly recompiled. I am simply not able to understand what kind of "performance improvement" this change will provide. I think that this will actually have the reverse effect. All thoughts welcome. Thanks in advance, Raj

    Read the article

  • SCD2 + Merge Statement + MSSQL

    - by Nev_Rahd
    I am trying work out with MERGE statment to Insert / Update Dimension Table of Type SCD2 My source is a Table var to Merge with Dimension table. My Merget statement is throwing an error as: The target table 'DM.DATA_ERROR.ERROR_DIMENSION' of the INSERT statement cannot be on either side of a (primary key, foreign key) relationship when the FROM clause contains a nested INSERT, UPDATE, DELETE, or MERGE statement. Found reference constraint 'FK_ERROR_DIMENSION_to_AUDIT_CreatedBy'. My Merge Statement: DECLARE @DATAERROROBJECT AS [ERROR_DIMENSION] INSERT INTO DM.DATA_ERROR.ERROR_DIMENSION SELECT ERROR_CODE, DATA_STREAM_ID, [ERROR_SEVERITY], DATA_QUALITY_RATING, ERROR_LONG_DESCRIPTION, ERROR_DESCRIPTION, VALIDATION_RULE, ERROR_TYPE, ERROR_CLASS, VALID_FROM, VALID_TO, CURR_FLAG, CREATED_BY_AUDIT_SK, UPDATED_BY_AUDIT_SK FROM (MERGE DM.DATA_ERROR.ERROR_DIMENSION ED USING @DATAERROROBJECT OBJ ON(ED.ERROR_CODE = OBJ.ERROR_CODE AND ED.DATA_STREAM_ID = OBJ.DATA_STREAM_ID) WHEN NOT MATCHED THEN INSERT VALUES( OBJ.ERROR_CODE ,OBJ.DATA_STREAM_ID ,OBJ.[ERROR_SEVERITY] ,OBJ.DATA_QUALITY_RATING ,OBJ.ERROR_LONG_DESCRIPTION ,OBJ.ERROR_DESCRIPTION ,OBJ.VALIDATION_RULE ,OBJ.ERROR_TYPE ,OBJ.ERROR_CLASS ,GETDATE() ,'9999-12-13' ,'Y' ,1 ,1 ) WHEN MATCHED AND ED.CURR_FLAG = 'Y' AND ( ED.[ERROR_SEVERITY] <> OBJ.[ERROR_SEVERITY] OR ED.[DATA_QUALITY_RATING] <> OBJ.[DATA_QUALITY_RATING] OR ED.[ERROR_LONG_DESCRIPTION] <> OBJ.[ERROR_LONG_DESCRIPTION] OR ED.[ERROR_DESCRIPTION] <> OBJ.[ERROR_DESCRIPTION] OR ED.[VALIDATION_RULE] <> OBJ.[VALIDATION_RULE] OR ED.[ERROR_TYPE] <> OBJ.[ERROR_TYPE] OR ED.[ERROR_CLASS] <> OBJ.[ERROR_CLASS] ) THEN UPDATE SET ED.CURR_FLAG = 'N', ED.VALID_TO = GETDATE() OUTPUT $ACTION ACTION_OUT, OBJ.ERROR_CODE ERROR_CODE, OBJ.DATA_STREAM_ID DATA_STREAM_ID, OBJ.[ERROR_SEVERITY] [ERROR_SEVERITY], OBJ.DATA_QUALITY_RATING DATA_QUALITY_RATING, OBJ.ERROR_LONG_DESCRIPTION ERROR_LONG_DESCRIPTION, OBJ.ERROR_DESCRIPTION ERROR_DESCRIPTION, OBJ.VALIDATION_RULE VALIDATION_RULE, OBJ.ERROR_TYPE ERROR_TYPE, OBJ.ERROR_CLASS ERROR_CLASS, GETDATE() VALID_FROM, '9999-12-31' VALID_TO, 'Y' CURR_FLAG, 555 CREATED_BY_AUDIT_SK, 555 UPDATED_BY_AUDIT_SK ) AS MERGE_OUT WHERE MERGE_OUT.ACTION_OUT = 'UPDATE'; What am i doing wrong ?

    Read the article

  • Why do case class companion objects extend FunctionN?

    - by retronym
    When you create a case class, the compiler creates a corresponding companion object with a few of the case class goodies: an apply factory method matching the primary constructor, equals, hashCode, and copy. Somewhat oddly, this generated object extends FunctionN. scala> case class A(a: Int) defined class A scala> A: (Int => A) res0: (Int) => A = <function1> This is only the case if: There is no manually defined companion object There is exactly one parameter list There are no type arguments The case class isn't abstract. Seems like this was added about two years ago. The latest incarnation is here. Does anyone use this, or know why it was added? It increases the size of the generated bytecode a little with static forwarder methods, and shows up in the #toString() method of the companion objects: scala> case class A() defined class A scala> A.toString res12: java.lang.String = <function0>

    Read the article

  • uploading image & getting back from database

    - by Anup Prakash
    Putting a set of code which is pushing image to database and fetching back from database: <!-- <?php error_reporting(0); // Connect to database $errmsg = ""; if (! @mysql_connect("localhost","root","")) { $errmsg = "Cannot connect to database"; } @mysql_select_db("test"); $q = <<<CREATE create table image ( pid int primary key not null auto_increment, title text, imgdata longblob, friend text) CREATE; @mysql_query($q); // Insert any new image into database if (isset($_POST['submit'])) { move_uploaded_file($_FILES['imagefile']['tmp_name'],"latest.img"); $instr = fopen("latest.img","rb"); $image = addslashes(fread($instr,filesize("latest.img"))); if (strlen($instr) < 149000) { $image_query="insert into image (title, imgdata,friend) values (\"". $_REQUEST['title']. "\", \"". $image. "\",'".$_REQUEST['friend']."')"; mysql_query ($image_query) or die("query error"); } else { $errmsg = "Too large!"; } $resultbytes=''; // Find out about latest image $query = "select * from image where pid=1"; $result = @mysql_query("$query"); $resultrow = @mysql_fetch_assoc($result); $gotten = @mysql_query("select * from image order by pid desc limit 1"); if ($row = @mysql_fetch_assoc($gotten)) { $title = htmlspecialchars($row[title]); $bytes = $row[imgdata]; $resultbytes = $row[imgdata]; $friend=$row[friend]; } else { $errmsg = "There is no image in the database yet"; $title = "no database image available"; // Put up a picture of our training centre $instr = fopen("../wellimg/ctco.jpg","rb"); $bytes = fread($instr,filesize("../wellimg/ctco.jpg")); } if ($resultbytes!='') { echo $resultbytes; } } ?> <html> <head> <title>Upload an image to a database</title> </head> <body bgcolor="#FFFF66"> <form enctype="multipart/form-data" name="file_upload" method="post"> <center> <div id="image" align="center"> <h2>Heres the latest picture</h2> <font color=red><?php echo $errmsg; ?></font> <b><?php echo $title ?></center> </div> <hr> <h2>Please upload a new picture and title</h2> <table align="center"> <tr> <td>Select image to upload: </td> <td><input type="file" name="imagefile"></td> </tr> <tr> <td>Enter the title for picture: </td> <td><input type="text" name="title"></td> </tr> <tr> <td>Enter your friend's name:</td> <td><input type="text" name="friend"></td> </tr> <tr> <td><input type="submit" name="submit" value="submit"></td> <td></td> </tr> </table> </form> </body> </html> --> Above set of code has one problem. The problem is whenever i pressing the "submit" button. It is just displaying the image on a page. But it is leaving all the html codes. even any new line message after the // Printing image on browser echo $resultbytes; //************************// So, for this i put this set of code in html tag: This is other sample code: <!-- <?php error_reporting(0); // Connect to database $errmsg = ""; if (! @mysql_connect("localhost","root","")) { $errmsg = "Cannot connect to database"; } @mysql_select_db("test"); $q = <<<CREATE create table image ( pid int primary key not null auto_increment, title text, imgdata longblob, friend text) CREATE; @mysql_query($q); // Insert any new image into database if (isset($_POST['submit'])) { move_uploaded_file($_FILES['imagefile']['tmp_name'],"latest.img"); $instr = fopen("latest.img","rb"); $image = addslashes(fread($instr,filesize("latest.img"))); if (strlen($instr) < 149000) { $image_query="insert into image (title, imgdata,friend) values (\"". $_REQUEST['title']. "\", \"". $image. "\",'".$_REQUEST['friend']."')"; mysql_query ($image_query) or die("query error"); } else { $errmsg = "Too large!"; } $resultbytes=''; // Find out about latest image $query = "select * from image where pid=1"; $result = @mysql_query("$query"); $resultrow = @mysql_fetch_assoc($result); $gotten = @mysql_query("select * from image order by pid desc limit 1"); if ($row = @mysql_fetch_assoc($gotten)) { $title = htmlspecialchars($row[title]); $bytes = $row[imgdata]; $resultbytes = $row[imgdata]; $friend=$row[friend]; } else { $errmsg = "There is no image in the database yet"; $title = "no database image available"; // Put up a picture of our training centre $instr = fopen("../wellimg/ctco.jpg","rb"); $bytes = fread($instr,filesize("../wellimg/ctco.jpg")); } } ?> <html> <head> <title>Upload an image to a database</title> </head> <body bgcolor="#FFFF66"> <form enctype="multipart/form-data" name="file_upload" method="post"> <center> <div id="image" align="center"> <h2>Heres the latest picture</h2> <?php if ($resultbytes!='') { // Printing image on browser echo $resultbytes; } ?> <font color=red><?php echo $errmsg; ?></font> <b><?php echo $title ?></center> </div> <hr> <h2>Please upload a new picture and title</h2> <table align="center"> <tr> <td>Select image to upload: </td> <td><input type="file" name="imagefile"></td> </tr> <tr> <td>Enter the title for picture: </td> <td><input type="text" name="title"></td> </tr> <tr> <td>Enter your friend's name:</td> <td><input type="text" name="friend"></td> </tr> <tr> <td><input type="submit" name="submit" value="submit"></td> <td></td> </tr> </table> </form> </body> </html> --> ** But in this It is showing the image in format of special charaters and digits. 1) So, Please help me to print the image with some HTML code. So that i can print it in my form to display the image. 2) Is there any way to convert the database image into real image, so that i can store it into my hard-disk and call it from tag? Please help me.

    Read the article

  • JPA joined column allow every value...

    - by Fabio Beoni
    I'm testing JPA, in a simple case File/FileVersions tables (Master/Details), with OneToMany relation, I have this problem: in FileVersions table, the field "file_id" (responsable for the relation with File table) accepts every values, not only values from File table. How can I use the JPA mapping to limit the input in FileVersion.file_id only for values existing in File.id? My class are File and FileVersion: FILE CLASS @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name="FILE_ID") private Long id; @Column(name="NAME", nullable = false, length = 30) private String name; //RELATIONS ------------------------------------------- @OneToMany(mappedBy="file", fetch=FetchType.EAGER) private Collection <FileVersion> fileVersionsList; //----------------------------------------------------- FILEVERSION CLASS @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name="VERSION_ID") private Long id; @Column(name="FILENAME", nullable = false, length = 255) private String fileName; @Column(name="NOTES", nullable = false, length = 200) private String notes; //RELATIONS ------------------------------------------- @ManyToOne(fetch=FetchType.EAGER) @JoinColumn(name="FILE_ID", referencedColumnName="FILE_ID", nullable=false) private File file; //----------------------------------------------------- and this is the FILEVERSION TABLE CREATE TABLE `JPA-Support`.`FILEVERSION` ( `VERSION_ID` bigint(20) NOT NULL AUTO_INCREMENT, `FILENAME` varchar(255) NOT NULL, `NOTES` varchar(200) NOT NULL, `FILE_ID` bigint(20) NOT NULL, PRIMARY KEY (`VERSION_ID`), KEY `FK_FILEVERSION_FILE_ID` (`FILE_ID`) ) ENGINE=MyISAM AUTO_INCREMENT=4 DEFAULT CHARSET=latin1

    Read the article

  • Would anybody recommend learning J/K/APL?

    - by ozan
    I came across J/K/APL a few months ago while working my way through some project euler problems, and was intrigued, to say the least. For every elegant-looking 20 line python solution I produced, there'd be a gobsmacking 20 character J solution that ran in a tenth of the time. I've been keen to learn some basic J, and have made a few attempts at picking up the vocabulary, but have found the learning curve to be quite steep. To those who are familiar with these languages, would you recommend investing some time to learn one (I'm thinking J in particular)? I would do so more for the purpose of satisfying my curiosity than for career advancement or some such thing. Some personal circumstances to consider, if you care to: I love mathematics, and use it daily in my work (as a mathematician for a startup) but to be honest I don't really feel limited by the tools that I use (like python + NumPy) so I can't use that excuse. I have no particular desire to work in the finance industry, which seems to be the main port of call for K users at least. Plus I should really learn C# as a next language as it's the primary language where I work. So practically speaking, J almost definitely shouldn't be the next language I learn. I'm reasonably familiar with MATLAB so using an array-based programming language wouldn't constitute a tremendous paradigm shift. Any advice from those familiar with these languages would be much appreciated.

    Read the article

  • Passive and active sockets

    - by davsan
    Quoting from this socket tutorial: Sockets come in two primary flavors. An active socket is con­nect­ed to a remote active socket via an open data con­nec­tion... A passive socket is not con­nect­ed, but rather awaits an in­com­ing con­nec­tion, which will spawn a new active socket once a con­nec­tion is es­tab­lished ... Each port can have a single passive socket binded to it, await­ing in­com­ing con­nec­tions, and mul­ti­ple active sockets, each cor­re­spond­ing to an open con­nec­tion on the port. It's as if the factory worker is waiting for new mes­sages to arrive (he rep­re­sents the passive socket), and when one message arrives from a new sender, he ini­ti­ates a cor­re­spon­dence (a con­nec­tion) with them by del­e­gat­ing someone else (an active socket) to ac­tu­al­ly read the packet and respond back to the sender if nec­es­sary. This permits the factory worker to be free to receive new packets. ... Then the tutorial explains that, after a connection is established, the active socket continues receiving data until there are no remaining bytes, and then closes the connection. What I didn't understand is this: Suppose there's an incoming connection to the port, and the sender wants to send some little data every 20 minutes. If the active socket closes the connection when there are no remaining bytes, does the sender have to reconnect to the port every time it wants to send data? How do we persist a once established connection for a longer time? Can you tell me what I'm missing here? My second question is, who determines the limit of the concurrently working active sockets?

    Read the article

  • A many-to-many relation joined disallows intellisense/lookup in joined table

    - by BerggreenDK
    I want to be able to select a product and retrieve all sub-parts(products) within it. My approach is to find the Product id and then retrieve the list of ProductParts with that as a parent and while fetching those, follow the key back to the Product child to get the name and details of each Part. I was hoping to use something similar to: part.linked_product_id.name I have two tables. One for [Product] and and a relation [ProductPart] that has two FK ID's to [Product] Table Product() { int ID; // (PRIMARY, NOT NULL) String Name; ... details removed for overview purpose... } Table ProductPart() { int Product_ID; // FK (linked with relation to Product/parent) int Part_Product_ID; // FK (linked with relation to Product/childen) ... details removed for overview purpose... } I have checked the SQL-diagram and it shows the two relations (both are one to many) and in my DBML they also looks right. Here is my LINQ to SQL snippet that doesnt work for me... wondering why my joins dont work as supposed. FaultySnippet() { ProductDataContext db = new ProductDataContext(); var list = ( from part in db.ProductParts join prod in db.Products on part.Part_Product_ID equals prod.ID where (part.Product_ID == product_ID) select new { Name = part.Part_Product_ID. ?? // <-- NO details from Joined table? ... rest of properties from ProductPart join... I hoped... } ); }

    Read the article

  • Is JPA persistence.xml classpath located?

    - by Vinnie
    Here's what I'm trying to do. I'm using JPA persistence in a web application, but I have a set of unit tests that I want to run outside of a container. I have my primary persistence.xml in the META_INF folder of my main app and it works great in the container (Glassfish). I placed a second persistence.xml in the META-INF folder of my test-classes directory. This contains a separate persistence unit that I want to use for test only. In eclipse, I placed this folder higher in the classpath than the default folder and it seems to work. Now when I run the maven build directly from the command line and it attempts to run the unit tests, the persistence.xml override is ignored. I can see the override in the META-INF folder of the maven generated test-classes directory and I expected the maven tests to use this file, but it isn't. My Spring test configuration overrides, achieved in a similar fashion are working. I'm confused at to whether the persistence.xml is located through the classpath. If it were, my override should work like the spring override since the maven surefire plugin explains "[The test class directory] will be included at the beginning the test classpath". Did I wrongly anticipate how the persistence.xml file is located? I could (and have) create a second persistence unit in the production persistence.xml file, but it feels dirty to place test configuration into this production file. Any other ideas on how to achieve my goal is welcome.

    Read the article

  • What's the most efficient query?

    - by Aaron Carlino
    I have a table named Projects that has the following relationships: has many Contributions has many Payments In my result set, I need the following aggregate values: Number of unique contributors (DonorID on the Contribution table) Total contributed (SUM of Amount on Contribution table) Total paid (SUM of PaymentAmount on Payment table) Because there are so many aggregate functions and multiple joins, it gets messy do use standard aggregate functions the the GROUP BY clause. I also need the ability to sort and filter these fields. So I've come up with two options: Using subqueries: SELECT Project.ID AS PROJECT_ID, (SELECT SUM(PaymentAmount) FROM Payment WHERE ProjectID = PROJECT_ID) AS TotalPaidBack, (SELECT COUNT(DISTINCT DonorID) FROM Contribution WHERE RecipientID = PROJECT_ID) AS ContributorCount, (SELECT SUM(Amount) FROM Contribution WHERE RecipientID = PROJECT_ID) AS TotalReceived FROM Project; Using a temporary table: DROP TABLE IF EXISTS Project_Temp; CREATE TEMPORARY TABLE Project_Temp (project_id INT NOT NULL, total_payments INT, total_donors INT, total_received INT, PRIMARY KEY(project_id)) ENGINE=MEMORY; INSERT INTO Project_Temp (project_id,total_payments) SELECT `Project`.ID, IFNULL(SUM(PaymentAmount),0) FROM `Project` LEFT JOIN `Payment` ON ProjectID = `Project`.ID GROUP BY 1; INSERT INTO Project_Temp (project_id,total_donors,total_received) SELECT `Project`.ID, IFNULL(COUNT(DISTINCT DonorID),0), IFNULL(SUM(Amount),0) FROM `Project` LEFT JOIN `Contribution` ON RecipientID = `Project`.ID GROUP BY 1 ON DUPLICATE KEY UPDATE total_donors = VALUES(total_donors), total_received = VALUES(total_received); SELECT * FROM Project_Temp; Tests for both are pretty comparable, in the 0.7 - 0.8 seconds range with 1,000 rows. But I'm really concerned about scalability, and I don't want to have to re-engineer everything as my tables grow. What's the best approach?

    Read the article

  • Filtering on a left join in SQLalchemy

    - by Adam Ernst
    Using SQLalchemy I want to perform a left outer join and filter out rows that DO have a match in the joined table. I'm sending push notifications, so I have a Notification table. This means I also have a ExpiredDeviceId table to store device_ids that are no longer valid. (I don't want to just delete the affected notifications as the user might later re-install the app, at which point the notifications should resume according to Apple's docs.) CREATE TABLE Notification (device_id TEXT, time DATETIME); CREATE TABLE ExpiredDeviceId (device_id TEXT PRIMARY KEY, expiration_time DATETIME); Note: there may be multiple Notifications per device_id. There is no "Device" table for each device. So when doing SELECT FROM Notification I should filter accordingly. I can do it in SQL: SELECT * FROM Notification LEFT OUTER JOIN ExpiredDeviceId ON Notification.device_id = ExpiredDeviceId.device_id WHERE expiration_time == NULL But how can I do it in SQLalchemy? sess.query( Notification, ExpiredDeviceId ).outerjoin( (ExpiredDeviceId, Notification.device_id == ExpiredDeviceId.device_id) ).filter( ??? ) Alternately I could do this with a device_id NOT IN (SELECT device_id FROM ExpiredDeviceId) clause, but that seems way less efficient.

    Read the article

< Previous Page | 173 174 175 176 177 178 179 180 181 182 183 184  | Next Page >