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  • Ways to Actively Update Java from MySQL

    - by 8EM
    What is the best way to update a Java or GWT program from MySQL. For example, a MySQL database which holds Weather information... updating whenever the weather changes a degree. How would I update a Java / GWT field with each update. Would I use a thread to query every few seconds??

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  • Does SQL Server have any kind of magic undo feature?

    - by Andrew G. Johnson
    Long story short is I tried to quickly update a single row in SQL Server using the Management studio and just typed UPDATE table SET column='value' and forgot the WHERE other_column='other_value' portion. Went for lunch, came back and theres 15 unread emails waiting for me. Happened about an hour ago, waiting for the database guy to come back to see when the last backup was. There's no magic UNDO feature though is there?

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  • Can MySQL reasonably perform queries on billions of rows?

    - by haxney
    I am planning on storing scans from a mass spectrometer in a MySQL database and would like to know whether storing and analyzing this amount of data is remotely feasible. I know performance varies wildly depending on the environment, but I'm looking for the rough order of magnitude: will queries take 5 days or 5 milliseconds? Input format Each input file contains a single run of the spectrometer; each run is comprised of a set of scans, and each scan has an ordered array of datapoints. There is a bit of metadata, but the majority of the file is comprised of arrays 32- or 64-bit ints or floats. Host system |----------------+-------------------------------| | OS | Windows 2008 64-bit | | MySQL version | 5.5.24 (x86_64) | | CPU | 2x Xeon E5420 (8 cores total) | | RAM | 8GB | | SSD filesystem | 500 GiB | | HDD RAID | 12 TiB | |----------------+-------------------------------| There are some other services running on the server using negligible processor time. File statistics |------------------+--------------| | number of files | ~16,000 | | total size | 1.3 TiB | | min size | 0 bytes | | max size | 12 GiB | | mean | 800 MiB | | median | 500 MiB | | total datapoints | ~200 billion | |------------------+--------------| The total number of datapoints is a very rough estimate. Proposed schema I'm planning on doing things "right" (i.e. normalizing the data like crazy) and so would have a runs table, a spectra table with a foreign key to runs, and a datapoints table with a foreign key to spectra. The 200 Billion datapoint question I am going to be analyzing across multiple spectra and possibly even multiple runs, resulting in queries which could touch millions of rows. Assuming I index everything properly (which is a topic for another question) and am not trying to shuffle hundreds of MiB across the network, is it remotely plausible for MySQL to handle this? UPDATE: additional info The scan data will be coming from files in the XML-based mzML format. The meat of this format is in the <binaryDataArrayList> elements where the data is stored. Each scan produces = 2 <binaryDataArray> elements which, taken together, form a 2-dimensional (or more) array of the form [[123.456, 234.567, ...], ...]. These data are write-once, so update performance and transaction safety are not concerns. My naïve plan for a database schema is: runs table | column name | type | |-------------+-------------| | id | PRIMARY KEY | | start_time | TIMESTAMP | | name | VARCHAR | |-------------+-------------| spectra table | column name | type | |----------------+-------------| | id | PRIMARY KEY | | name | VARCHAR | | index | INT | | spectrum_type | INT | | representation | INT | | run_id | FOREIGN KEY | |----------------+-------------| datapoints table | column name | type | |-------------+-------------| | id | PRIMARY KEY | | spectrum_id | FOREIGN KEY | | mz | DOUBLE | | num_counts | DOUBLE | | index | INT | |-------------+-------------| Is this reasonable?

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  • Where can I find a web-project "security checklist?"

    - by iaagty
    I'm looking for a complete list of security guidelines for programming and deploying PHP web sites and applications on an Apache (Linux) server. Basically, a "security check list" to run through before finishing a project. I.e., Cross Site Scripting Cross Site Request Forgery Sanitize form data that goes into database Disable register globals and error reporting in custom php.ini Upload files below web root ...(the list goes on) I did some searching on the internet and in this forum, but couldn't find a comprehensive, succinct, and complete list of guidelines. Thanks in advance.

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  • Encrypting and decrypting strings

    - by dretzlaff17
    Does anyone know of a good way to encrypt and decrypt strings using VB6 to ensure sensitive data is secure? Also, is there an encryption method that can be shared between VB6 and .NET? Example: The encrypted string will be written to a database using a VB6 application, but the value also need to be read an decrypted in a c# .net application using the .net framework if possible. Thanks!

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  • Can I use Dlphi to write to BDE an PHP to read from it?

    - by mawg
    I strongly prefer not to use additional 3rd party components, libraries or DLLs (at least in v1.0), unless there is absolutely no other solution. Question: (how) can I use Delphi to programatically crate a BDE database and write to it, then use PHP to read from it? Any URLs for examples of tutorial?

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  • Add/Edit Columns in DataBound DataGridView

    - by Dave
    I've got a datagridview that is databound from a database table. How do I: a) Edit the displayed value for a column using the values from other columns in the row? (For example, display a URL like: <a href="/url?param=columnA">columnB</a> where columnA is the value from column A and columnB is the value from columnB) b) Add an additional column using values from the other columns (similar to a.)

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  • Java Swing how to create a task reminder

    - by newbie123
    How to create a event reminder. Example, an user created an event which is today 5.00pm and stored it into database. When ruun the program the reminder will pop up if the system time is 5.00pm. Is there any API can do that? From google what I got was those freeware.

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  • .NET timezone information

    - by dotnetrocks
    What is the standard format for datetime with timezone in a C# ASP.NET application? Updated to clarify: In ASP.NET I need to check a datetime from a Domino database against a .NET DateTime. The client is asking what would be the best format in which he should provide the datetime with the timezone. Meaning which format is most easily readable by .NET?

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  • How can I make exception handling for all existing SQL server 2005 Stored Procedures, view and funct

    - by Space Cracker
    we have a portal that have SQL server 2005 database that contain about 1750 stored procedures , 250 view and 200 function and 95% of them not have handling exception in their code .. we search about any way that allow us making such a global exception handling in SQL that receive any exception happen in any SP,view or function and stored it in a table we made .. is there something like this in SQL server 2005 or we must write exception handling code on each item ?

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  • How to implement callback methods inside classes (PHP)

    - by sombe
    I need to use a class callback method on an array inside another method (the callback function belongs to the class). class Database { public function escape_string_for_db($string){ return mysql_real_escape_string($string); } public function escape_all_array($array){ return array_filter($array,"$this->escape_string_for_db"); } } Is this the right way to go about that? (I mean, in terms of the second parameter passed to array_filter)

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  • Avoiding Zends Error Messages

    - by Kieran
    I am using the Zend Framework for ACL's in codeigniter but if something is not right in the database or there is an error with the code that interfaces with the framework then the framework displays its own error messages. Is there a way to suppress these?

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  • Displaying a Drop-Down List While Editing in the GridView

    - by kousik
    I have a datagrid which shows the search reasult(time entered by the user preveiously)on a button click event depending uppon the input name or date enter by the user,i want to show a drop down list for a field selection like depertment whenever user want to edit the data in datagridiew,i am using access database & asp3.5.

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  • How do I parse an HTML website using Perl?

    - by Nano HE
    Could you please give me some suggestions on how to parse HTML in Perl? I plan to parse the keywords(including URL links) and save them to a MySQL database. I am using Windows XP. Also, do I first need to download some website pages to the local hard drive with some offline Explorer tool? If I do, could you point me to a good download tool?

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  • Is there any rich text editor component for JSF RI ?

    - by Paul
    1.I am using JSF RI 1.1. How to add rich text editor component. pls tell me is there any rich text editor component available. 2. i am displaying set of images horizontally using the below code. selected image is stored in database. while showing the images in edit mode how to highlight the previously selected image. pls help me

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  • plot a line graph in vb.net

    - by Husna5207
    this is my function for plotting a graph in vb.net how I'm going to replace the ("Jon", 10),("Jordan", 30) with a value that i search from database ? Private Sub chart_btn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles chart_btn.Click Chart1.Series("Student").Points.AddXY("Jon", 10) Chart1.Series("Student").Points.AddXY("Jon", 10) Chart1.Series("Student").ChartType = System.Windows.Forms.DataVisualization.Charting.SeriesChartType.Bar End Sub

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  • Removal of table primary key in MySQL

    - by marionmaiden
    Hello, I've removed the primary key of one table of my MySQL database, but now, when I use the MySQL Administrator and try to edit some data of this table, it doesn't allow me to do this. The button edit that appears in the bottom of the table keeps visible, but disabled to click.

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  • Java: Making concurrent MySQL queries from multiple clients synchronised

    - by Misha Gale
    I work at a gaming cybercafe, and we've got a system here (smartlaunch) which keeps track of game licenses. I've written a program which interfaces with this system (actually, with it's backend MySQL database). The program is meant to be run on a client PC and (1) query the database to select an unused license from the pool available, then (2) mark this license as in use by the client PC. The problem is, I've got a concurrency bug. The program is meant to be launched simultaneously on multiple machines, and when this happens, some machines often try and acquire the same license. I think that this is because steps (1) and (2) are not synchronised, i.e. one program determines that license #5 is available and selects it, but before it can mark #5 as in use another copy of the program on another PC tries to grab that same license. I've tried to solve this problem by using transactions and table locking, but it doesn't seem to make any difference - Am I doing this right? Here follows the code in question: public LicenseKey Acquire() throws SmartLaunchException, SQLException { Connection conn = SmartLaunchDB.getConnection(); int PCID = SmartLaunchDB.getCurrentPCID(); conn.createStatement().execute("LOCK TABLE `licensekeys` WRITE"); String sql = "SELECT * FROM `licensekeys` WHERE `InUseByPC` = 0 AND LicenseSetupID = ? ORDER BY `ID` DESC LIMIT 1"; PreparedStatement statement = conn.prepareStatement(sql); statement.setInt(1, this.id); ResultSet results = statement.executeQuery(); if (results.next()) { int licenseID = results.getInt("ID"); sql = "UPDATE `licensekeys` SET `InUseByPC` = ? WHERE `ID` = ?"; statement = conn.prepareStatement(sql); statement.setInt(1, PCID); statement.setInt(2, licenseID); statement.executeUpdate(); statement.close(); conn.commit(); conn.createStatement().execute("UNLOCK TABLES"); return new LicenseKey(results.getInt("ID"), this, results.getString("LicenseKey"), results.getInt("LicenseKeyType")); } else { throw new SmartLaunchException("All licenses of type " + this.name + "are in use"); } }

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