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  • read as ASCII in dbf

    - by Meysam Javadi
    i have a dbf that contain some ASCII strings and must read these with their ASCII number and convert those with my list(a table that have equivalent character). but when i want to convert strings i found some illegal character(out of range that i have). i read dbf with this(i changed to Encoding.ASCII) and also with JET.

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  • Nhibernate HQL Subselect queries

    - by MegaByte
    Hi I have the following SQL query: select c.id from (select id from customers) c This query has no practical value - I simplified it greatly for the purpose of this post. My question: is it possible have a subquery in the from clause using HQL. If not, can I perhaps query the customers first, kinda like a temp table in sql, and then use the result as the source of the next query? thanks

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  • Flex+JPA/Hibernate+BlazeDS+MySQL how to debug this monster?!

    - by Zenzen
    Ok so I'm making a "simple" web app using the technologies from the topic, recently I found http://www.adobe.com/devnet/flex/articles/flex_hibernate.html so I'm following it and I try to apply it to my app, the only difference being I'm working on a Mac and I'm using MAMP for the database (so no command line for me). The thing is I'm having some trouble with retrieving/connecting to the database. I have the remoting-config.xml, persistance.xml, a News.java class (my Entity), a NewsService.java class, a News.as class - all just like in the tutorial. I have of course this line in one of my .mxmls: <mx:RemoteObject id="loaderService" destination="newsService" result="handleLoadResult(event)" fault="handleFault(event)" showBusyCursor="true" /> And my remoting-config.xml looks like this (well part of it): <destination id="newsService"> <properties><source>com.gamelist.news.NewsService</source></properties> </destination> NewsService has a method: public List<News> getLatestNews() { EntityManagerFactory emf = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT); EntityManager em = emf.createEntityManager(); Query findLatestQuery = em.createNamedQuery("news.findLatest"); List<News> news = findLatestQuery.getResultList(); return news; } And the named query is in the News class: @Entity @Table(name="GLT_NEWS") @NamedQueries({ @NamedQuery(name="news.findLatest", query="from GLT_NEWS order by new_date_added limit 5 ") }) The handledLoadResult looks like this: private function handleLoadResult(ev:ResultEvent):void { newsList = ev.result as ArrayCollection; newsRecords = newsList.length; } Where: [Bindable] private var newsList:ArrayCollection = new ArrayCollection(); But when I try to trigger: loaderService.getLatestNews(); nothing happens, newsList is empty. Few things I need to point out: 1) as I said I didn't install mysql manually, but I'm using MAMP (yes, the server's running), could this cause some trouble? 2) I already have a "gladm" database and I have a "GLT_NEWS" table with all the fields, is this bad? Basically the question is how am I suppose to debug this thing so I can find the mistake I'm making? I know that loadData() is executed (did a trace()), but I have no idea what happens with loaderService.getLatestNews()... @EDIT: ok so I see I'm getting an error in the "fault handler" which says "Error: Client.Error.MessageSend - Channel.Connect.Failed error NetConnection.Call.Failed: HTTP: Status 404: url: 'http://localhost:8080/WebContent/messagebroker/amf' - "

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  • Can I use a single DateTime field on the Entity Framework model side when the value is stored in a set of Int fields in the actual database?

    - by Ivan
    The actual table in the database has separate integer fields for storing year, month, day, hour and minute values (all in UTC) (seconds and milliseconds are irrelevant for my task and considered equal to zero). Needless to say it would be of great convenience to have just one field of DateTime type on the application side and hide all the conversion under the cover of the Entity Framework model code. Any directions on how to do that? I am not very experienced with Entity Framework yet.

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  • Sorting tree with other column in SQL Server 2008

    - by bodziec
    Hi, I have a table which implements a tree using hierarchyid column Sample data: People \ Girls \1\ Zoey \1\1\ Kate \1\2\ Monica \1\3\ Boys \2\ Mark \2\1\ David \2\2\ This is the order using hierarchyid column as sort column I would like to sort data using hierarchyid but also using name so it would look like this: People \ Boys \2\ David \2\2\ Mark \2\1\ Girls \1\ Kate \1\2\ Monica \1\3\ Zoey \1\1\ Is there a simple solution to do this? Czy da sie to zrobic w jednym zapytaniu sql ?

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  • Explanation of converting exporting an XML document as a relational database using XSLT

    - by Yaaqov
    I would like to better understand the basic steps needed to a take an XML document like this Breakfast Menu... <?xml version="1.0" encoding="ISO-8859-1"?> <breakfast_menu> <food> <name>Belgian Waffles</name> <price>$5.95</price> <description>two of our famous Belgian Waffles with plenty of real maple syrup</description> <calories>650</calories> </food> <food> <name>Strawberry Belgian Waffles</name> <price>$7.95</price> <description>light Belgian waffles covered with strawberries and whipped cream</description> <calories>900</calories> </food> <food> <name>Berry-Berry Belgian Waffles</name> <price>$8.95</price> <description>light Belgian waffles covered with an assortment of fresh berries and whipped cream</description> <calories>900</calories> </food> <food> <name>French Toast</name> <price>$4.50</price> <description>thick slices made from our homemade sourdough bread</description> <calories>600</calories> </food> <food> <name>Homestyle Breakfast</name> <price>$6.95</price> <description>two eggs, bacon or sausage, toast, and our ever-popular hash browns</description> <calories>950</calories> </food> </breakfast_menu> And "export" it to say, an Access or MySQL database using XSLT, creating two joined tables: Table: breakfast_menu Field: menu_item_id Field: food_id Table: food Field: food_id Field: name Field: price Field: description Field: calories If there are online tutorials on this that you know of, I'd be interesting in learning more, as well. Thanks.

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  • missing a using directive or an assembly reference

    - by cire1507
    I'm in the process of writing a small asp.net mvc application that is using the northwind.mdf. When building the solution I get this error: Error 1 The type or namespace name 'Order' could not be found (are you missing a using directive or an assembly reference?) Order is a table in the northwind database. any help is most appreciated.

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  • How to open multiple viewer windows in Toad?

    - by RemotecUk
    Im sure this is pretty simple but I just cant seem to find the option. My Toad MySql install only seems to allow me to have one "Viewer" window open and hence its impossible to view multiple tables - or have a window open for each table Im working with. Does anyone know how to change this?

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  • users authentication and dht

    - by mtasic
    Lets say that I have only DHT (distributed hash table) implemented (in Python), and I want to build authentication service over P2P network, but without introducing centralized authentication server with such a service. Can it be done, and if so how can I achieve this? I'm familiar with how Skype and Wuala have done this, but I am looking for decentralized solution without single point of failure.

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  • Simple Grouping With TableSorter Plugin

    - by HurnsMobile
    Im playing around with the Tablesorter plug-in for jQuery and was trying to get a very simple grouping functionality added into it. Using the follow html/js works great until you click sort again and reverse the order. The headers get moved to the bottom of the group when this happens. The following is my (admitedly hacky) attempt at it. Does anyone have any ideas? <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> <title>Table Manipulation Test</title> <link type="text/css" href="css/ui-lightness/jquery-ui-1.8.1.custom.css" rel="stylesheet" /> <link rel="stylesheet" href="tablesorter/themes/green/style.css" type="text/css"/> <script type="text/javascript" src="js/jquery-1.4.2.min.js"></script> <script type="text/javascript" src="js/jquery-ui-1.8.1.custom.min.js"></script> <script type="text/javascript" src="tablesorter/jquery.tablesorter.min.js"></script> <script type="text/javascript"> $(document).ready(function() { $("#test_table").tablesorter({ sortForce: [[3,0]] }); $(".group_details").hide(); $(".group_header").click(function(){ var group = $(this).attr("group"); var $expander = $(this).children("td.expanderguy") if ($("." + group + ":visible").length){ $("." + group + "").fadeOut('fast'); $expander.html("<img src='icons/plus.gif'>"); } else{ $("." + group + "").fadeIn('fast'); $expander.html("<img src='icons/minus.gif'>"); } }); } ); </script> <style type="text/css"> .group_header td{ background-color: #888888; !important } </style> </head> <body> <table id="test_table" class="tablesorter"> <thead> <tr><th>First Name</th><th>Last Name</th><th>Email</th><th>Due Date</th><th>Amount Due</th></tr> </thead> <tbody> <tr class="group_header" group="group1"><td class="expanderguy"><img src="icons/plus.gif"></td><td></td><td></td><td>Monday, June 7</td><td></td></tr> <tr class="group_details group1"><td>Flavian</td><td>Wenceslas</td><td>[email protected]</td><td>Monday, June 7</td><td>$100</td></tr> <tr class="group_details group1"><td>Gordian</td><td>Ives</td><td>[email protected]</td><td>Monday, June 7</td><td>$1700</td></tr> <tr class="group_details group1"><td>Saladin</td><td>Tarquin</td><td>[email protected]</td><td>Monday, June 7</td><td>$1700</td></tr> <tr class="group_details group1"><td>Urban</td><td>Cyprian</td><td>[email protected]</td><td>Monday, June 7</td><td>$1500</td></tr> <tr class="group_details group1"><td>Sargon</td><td>Swithun</td><td>[email protected]</td><td>Monday, June 7</td><td>$1100</td></tr> <tr class="group_details group1"><td>Pompey</td><td>Ladislas</td><td>[email protected]</td><td>Monday, June 7</td><td>$300</td></tr> <tr class="group_details group1"><td>Attila</td><td>Hiawatha</td><td>[email protected]</td><td>Monday, June 7</td><td>$200</td></tr> <tr class="group_header" group="group2"><td class="expanderguy"><img src="icons/plus.gif"></td><td></td><td></td><td>Tuesday, June 8</td><td></td></tr> <tr class="group_details group2"><td>Bruce</td><td>Fenton</td><td>[email protected]</td><td>Tuesday, June 8</td><td>$1700</td></tr> <tr class="group_details group2"><td>Wade</td><td>Sequoia</td><td>[email protected]</td><td>Tuesday, June 8</td><td>$1400</td></tr> <tr class="group_details group2"><td>Eddie</td><td>Jerold</td><td>[email protected]</td><td>Tuesday, June 8</td><td>$1100</td></tr> <tr class="group_details group2"><td>Lynn</td><td>Lucan</td><td>[email protected]</td><td>Tuesday, June 8</td><td>$1200</td></tr> <tr class="group_details group2"><td>Taegan</td><td>Tadg</td><td>[email protected]</td><td>Tuesday, June 8</td><td>$100</td></tr> <tr class="group_details group2"><td>Clyde</td><td>Reed</td><td>[email protected]</td><td>Tuesday, June 8</td><td>$6100</td></tr> <tr class="group_details group2"><td>Alaois</td><td>Art</td><td>[email protected]</td><td>Tuesday, June 8</td><td>$2100</td></tr> <tr class="group_details group2"><td>Gilbert</td><td>Patsy</td><td>[email protected]</td><td>Tuesday, June 8</td><td>$1500</td></tr> <tr class="group_header" group="group3"><td class="expanderguy"><img src="icons/plus.gif"></td><td></td><td></td><td>Wednesday, June 9</td><td></td></tr> <tr class="group_details group3" ><td>Clem</td><td>Eben</td><td>[email protected]</td><td>Wednesday, June 9</td><td>$2100</td></tr> <tr class="group_details group3" ><td>Elijah</td><td>Julyan</td><td>[email protected]</td><td>Wednesday, June 9</td><td>$2100</td></tr> <tr class="group_details group3" ><td>Marvyn</td><td>Damian</td><td>[email protected]</td><td>Wednesday, June 9</td><td>$1100</td></tr> <tr class="group_details group3" ><td>Sawyer</td><td>Ryker</td><td>[email protected]</td><td>Wednesday, June 9</td><td>$500</td></tr> </tbody> </table> </body>

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  • Adding db file to visual web developer

    - by iva123
    Hi, I'm beginner in visual web developer. I want to add a ready database to my project, to do that I simply add the db file to App_data folder. However, I can't see any table or database diagram etc. Am I missing a big part to add external source ? Any help? I'd appreciate it

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  • Schema qualified tables with SQLAlchemy, SQLite and Postgresql?

    - by Chris Reid
    I have a Pylons project and a SQLAlchemy model that implements schema qualified tables: class Hockey(Base): __tablename__ = "hockey" __table_args__ = {'schema':'winter'} hockey_id = sa.Column(sa.types.Integer, sa.Sequence('score_id_seq', optional=True), primary_key=True) baseball_id = sa.Column(sa.types.Integer, sa.ForeignKey('summer.baseball.baseball_id')) This code works great with Postgresql but fails when using SQLite on table and foreign key names (due to SQLite's lack of schema support) sqlalchemy.exc.OperationalError: (OperationalError) unknown database "winter" 'PRAGMA "winter".table_info("hockey")' () I'd like to continue using SQLite for dev and testing. Is there a way of have this fail gracefully on SQLite?

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  • SQL Replace Into question

    - by Matt
    With Replace Into, if I have two fields. FirstName LastName. The table has John Smith in it, if I was to run REPLACE INTO tblNames (FirstName, LastName) VALUES (John, Jones) Would that replace Smith with Jones, or create a new name? What determines if its an Update or and Insert?

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  • Use of HAVING in MySQL

    - by KBrian
    I have a table from which I need to select all persons that have a first name that is not unique and that that set should be selected only if among the persons with a similar first name, all have a different last name. Example: FirstN LastN Bill Clinton Bill Cosby Bill Maher Elvis Presley Elvis Presley Largo Winch I want to obtain FirstN LastN Bill Clinton or FirstN LastN Bill Clinton Bill Cosby Bill Maher I tried this but it does not return what I want. SELECT * FROM Ids GROUP BY FirstN, LastN HAVING (COUNT(FirstN)>1 AND COUNT(LastN)=1)) [Edited my post after Aleandre P. Lavasseur remark]

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  • How to bulk insert from CSV when some fields have new line character?

    - by z-boss
    I have a CSV dump from another DB that looks like this (id, name, notes): 1001,John Smith,15 Main Street 1002,Jane Smith,"2010 Rockliffe Dr. Pleasantville, IL USA" 1003,Bill Karr,2820 West Ave. The last field may contain carriage returns and commas, in which case it is surrounded by double quotes. I use this code to import CSV into my table: BULK INSERT CSVTest FROM 'c:\csvfile.csv' WITH ( FIELDTERMINATOR = ',', ROWTERMINATOR = '\n' ) SQL Server 2005 bulk insert cannot figure out that carriage returns inside quotes are not row terminators. How to overcome?

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  • CakePHP Test Fixtures Drop My Tables Permanently After Running A Test Case

    - by Frank
    I'm not sure what I've done wrong in my CakePHP unit test configuration. Every time I run a test case, the model tables associated with my fixtures are missing form my test database. After running an individual test case I have to re-import my database tables using phpMyAdmin. Here are the relevant files: This is the class I'm trying to test comment.php. This table is dropped after the test. App::import('Sanitize'); class Comment extends AppModel{ public $name = 'Comment'; public $actsAs = array('Tree'); public $belongsTo = array('User' => array('fields'=>array('id', 'username'))); public $validate = array( 'text' = array( 'rule' =array('between', 1, 4000), 'required' ='true', 'allowEmpty'='false', 'message' = "You can't leave your comment text empty!") ); database.php class DATABASE_CONFIG { var $default = array( 'driver' = 'mysql', 'persistent' = false, 'host' = 'project.db', 'login' = 'projectman', 'password' = 'projectpassword', 'database' = 'projectdb', 'prefix' = '' ); var $test = array( 'driver' = 'mysql', 'persistent' = false, 'host' = 'project.db', 'login' = 'projectman', 'password' = 'projectpassword', 'database' = 'testprojectdb', 'prefix' = '' ); } My comment.test.php file. This is the table that keeps getting dropped. <?php App::import('Model', 'Comment'); class CommentTestCase extends CakeTestCase { public $fixtures = array('app.comment', 'app.user'); function start(){ $this-Comment =& ClassRegistry::init('Comment'); $this-Comment-useDbConfig = 'test_suite'; } This is my comment_fixture.php class: <?php class CommentFixture extends CakeTestFixture { var $name = "Comment"; var $import = 'Comment'; } And just in case, here is a typical test method in the CommentTestCase class function testMsgNotificationUserComment(){ $user_id = '1'; $submission_id = '1'; $parent_id = $this-Comment-commentOnModel('Submission', $submission_id, '0', $user_id, "Says: A"); $other_user_id = '2'; $msg_id = $this-Comment-commentOnModel('Submission', $submission_id, $parent_id, $other_user_id, "Says: B"); $expected = array(array('Comment'=array('id'=$msg_id, 'text'="Says: B", 'submission_id'=$submission_id, 'topic_id'='0', 'ack'='0'))); $result = $this-Comment-getMessages($user_id); $this-assertEqual($result, $expected); } I've been dealing with this for a day now and I'm starting to be put off by CakePHP's unit testing. In addition to this issue -- Servral times now I've had data inserted into by 'default' database configuration after running tests! What's going on with my configuration?!

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  • What Causes Boost Asio to Crash Like This?

    - by Scott Lawson
    My program appears to run just fine most of the time, but occasionally I get a segmentation fault. boost version = 1.41.0 running on RHEL 4 compiled with GCC 3.4.6 Backtrace: #0 0x08138546 in boost::asio::detail::posix_fd_set_adapter::is_set (this=0xb74ed020, descriptor=-1) at /home/scottl/boost_1_41_0/boost/asio/detail/posix_fd_set_adapter.hpp:57 __result = -1 'ÿ' #1 0x0813e1b0 in boost::asio::detail::reactor_op_queue::perform_operations_for_descriptors (this=0x97f3b6c, descriptors=@0xb74ed020, result=@0xb74ecec8) at /home/scottl/boost_1_41_0/boost/asio/detail/reactor_op_queue.hpp:204 op_iter = {_M_node = 0xb4169aa0} i = {_M_node = 0x97f3b74} #2 0x081382ca in boost::asio::detail::select_reactor::run (this=0x97f3b08, block=true) at /home/scottl/boost_1_41_0/boost/asio/detail/select_reactor.hpp:388 read_fds = {fd_set_ = {fds_bits = {16, 0 }}, max_descriptor_ = 65} write_fds = {fd_set_ = {fds_bits = {0 }}, max_descriptor_ = -1} retval = 1 lock = { = {}, mutex_ = @0x97f3b1c, locked_ = true} except_fds = {fd_set_ = {fds_bits = {0 }}, max_descriptor_ = -1} max_fd = 65 tv_buf = {tv_sec = 0, tv_usec = 710000} tv = (timeval *) 0xb74ecf88 ec = {m_val = 0, m_cat = 0x81f2c24} sb = { = {}, blocked_ = true, old_mask_ = {__val = {0, 0, 134590223, 3075395548, 3075395548, 3075395464, 134729792, 3075395360, 135890240, 3075395368, 134593920, 3075395544, 135890240, 3075395384, 134599542, 3020998404, 135890240, 3075395400, 134614095, 3075395544, 4, 3075395416, 134548135, 3021172996, 4294967295, 3075395432, 134692921, 3075395504, 0, 3075395448, 134548107, 3021172992}}} #3 0x0812eb45 in boost::asio::detail::task_io_service ::do_one (this=0x97f3a70, lock=@0xb74ed230, this_idle_thread=0xb74ed240, ec=@0xb74ed2c0) at /home/scottl/boost_1_41_0/boost/asio/detail/task_io_service.hpp:260 more_handlers = false c = {lock_ = @0xb74ed230, task_io_service_ = @0x97f3a70} h = (boost::asio::detail::handler_queue::handler *) 0x97f3aa0 polling = false task_has_run = true #4 0x0812765f in boost::asio::detail::task_io_service ::run (this=0x97f3a70, ec=@0xb74ed2c0) at /home/scottl/boost_1_41_0/boost/asio/detail/task_io_service.hpp:103 ctx = { = {}, owner_ = 0x97f3a70, next_ = 0x0} this_idle_thread = {wakeup_event = { = {}, cond_ = {__c_lock = { __status = 0, __spinlock = 22446}, __c_waiting = 0x2bd7, __padding = "\000\000\000\000×+\000\000\000\000\000\000×+\000\000\000\000\000\000\204:\177\t\000\000\000", __align = 0}, signalled_ = true}, next = 0x0} lock = { = {}, mutex_ = @0x97f3a84, locked_ = false} n = 11420 #5 0x08125e99 in boost::asio::io_service::run (this=0x97ebbcc) at /home/scottl/boost_1_41_0/boost/asio/impl/io_service.ipp:58 ec = {m_val = 0, m_cat = 0x81f2c24} s = 8 #6 0x08154424 in boost::_mfi::mf0::operator() (this=0x9800870, p=0x97ebbcc) at /home/scottl/boost_1_41_0/boost/bind/mem_fn_template.hpp:49 No locals. #7 0x08154331 in boost::_bi::list1 ::operator(), boost::_bi::list0 (this=0x9800878, f=@0x9800870, a=@0xb74ed337) at /home/scottl/boost_1_41_0/boost/bind/bind.hpp:236 No locals. #8 0x081541e5 in boost::_bi::bind_t, boost::_bi::list1 ::operator() (this=0x9800870) at /home/scottl/boost_1_41_0/boost/bind/bind_template.hpp:20 a = {} #9 0x08154075 in boost::detail::thread_data, boost::_bi::list1 ::run (this=0x98007a0) at /home/scottl/boost_1_41_0/boost/thread/detail/thread.hpp:56 No locals. #10 0x0816fefd in thread_proxy () at /usr/lib/gcc/i386-redhat-linux/3.4.6/../../../../include/c++/3.4.6/bits/locale_facets.tcc:2443 __ioinit = {static _S_refcount = , static _S_synced_with_stdio = } ---Type to continue, or q to quit--- typeinfo for common::RuntimeException = {} typeinfo name for common::RuntimeException = "N6common16RuntimeExceptionE" #11 0x00af23cc in start_thread () from /lib/tls/libpthread.so.0 No symbol table info available. #12 0x00a5c96e in __init_misc () from /lib/tls/libc.so.6 No symbol table info available.

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  • Storing Icons and Sql with PHP

    - by Ole Jak
    So I have a simple Apache with MySql I am developing a PHP app. I have Users Table in my DB. I vant to let them store Icons. My question Is what's the best way of attaching such data as icons (100-250kb's) to DB - Is it beter to store them Inside DB or store them as File and some how attaching links to icons into DB. What's the best way? Are there any classes that automate this process (of attaching such data to DB)?

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  • SQL - Order against two columns at the same time (intersecting)

    - by Alex
    I have a table with the fields CommonName and FirstName. Only either field has data, never both. Is there a way to order rows in an intersecting manner on SQL Server? Example: CommonName FirstName Bern Wade Ashley Boris Ayana I want records ordered like this: CommonName FirstName Ashley Ayana Bern Boris Wade Is this possible, and if so, how?

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  • Invalid parameter number: number of bound variables does not match number of tokens

    - by Alex
    I have a table: 'objects' with few columns: object_id:int, object_type:int, object_status:int, object_lati:float, object_long:float My query is : $stmt = $db->query('SELECT o.object_id, o.object_type, o.object_status, o.object_lati, o.object_long FROM objects o WHERE o.object_id = 1'); $res = $stmt->fetch(); Pdo throw error: SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens When i remove column object_lati or object_long query is work fine.

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  • LINQ to SQL does not update when data has changed in database

    - by aximili
    I have this problem where after a field (say Field3 in table MyTable) is updated on the database, MyTable.Field3 (in C#) is still returning the old value. I suspect there is some caching...? How do I force it to: Read the value from the database? OR Update the value in the MyTable class? Or is there anything I miss? Thank you in advance.

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  • How to use CASE in SQL , Syntax Error being shown

    - by Shantanu Gupta
    I am trying to retrieve some records from table based on my query but it shows me an error Msg 102, Level 15, State 1, Line 2 Incorrect syntax near ' select vd.LedgerId,(CreditAmt-DebitAmt) AS NET, CASE NET WHEN NET > 0 THEN 'Debit' WHEN NET < 0 THEN 'Credit' ELSE 'Nil'End from dbo.vdebit vd INNER JOIN dbo.vCredit vc ON vd.LedgerId=vc.LedgerId

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  • With sqlalchemy how to dynamically bind to database engine on a per-request basis

    - by Peter Hansen
    I have a Pylons-based web application which connects via Sqlalchemy (v0.5) to a Postgres database. For security, rather than follow the typical pattern of simple web apps (as seen in just about all tutorials), I'm not using a generic Postgres user (e.g. "webapp") but am requiring that users enter their own Postgres userid and password, and am using that to establish the connection. That means we get the full benefit of Postgres security. Complicating things still further, there are two separate databases to connect to. Although they're currently in the same Postgres cluster, they need to be able to move to separate hosts at a later date. We're using sqlalchemy's declarative package, though I can't see that this has any bearing on the matter. Most examples of sqlalchemy show trivial approaches such as setting up the Metadata once, at application startup, with a generic database userid and password, which is used through the web application. This is usually done with Metadata.bind = create_engine(), sometimes even at module-level in the database model files. My question is, how can we defer establishing the connections until the user has logged in, and then (of course) re-use those connections, or re-establish them using the same credentials, for each subsequent request. We have this working -- we think -- but I'm not only not certain of the safety of it, I also think it looks incredibly heavy-weight for the situation. Inside the __call__ method of the BaseController we retrieve the userid and password from the web session, call sqlalchemy create_engine() once for each database, then call a routine which calls Session.bind_mapper() repeatedly, once for each table that may be referenced on each of those connections, even though any given request usually references only one or two tables. It looks something like this: # in lib/base.py on the BaseController class def __call__(self, environ, start_response): # note: web session contains {'username': XXX, 'password': YYY} url1 = 'postgres://%(username)s:%(password)s@server1/finance' % session url2 = 'postgres://%(username)s:%(password)s@server2/staff' % session finance = create_engine(url1) staff = create_engine(url2) db_configure(staff, finance) # see below ... etc # in another file Session = scoped_session(sessionmaker()) def db_configure(staff, finance): s = Session() from db.finance import Employee, Customer, Invoice for c in [ Employee, Customer, Invoice, ]: s.bind_mapper(c, finance) from db.staff import Project, Hour for c in [ Project, Hour, ]: s.bind_mapper(c, staff) s.close() # prevents leaking connections between sessions? So the create_engine() calls occur on every request... I can see that being needed, and the Connection Pool probably caches them and does things sensibly. But calling Session.bind_mapper() once for each table, on every request? Seems like there has to be a better way. Obviously, since a desire for strong security underlies all this, we don't want any chance that a connection established for a high-security user will inadvertently be used in a later request by a low-security user.

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