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  • Can I ask Postgresql to ignore errors within a transaction

    - by fmark
    I use Postgresql with the PostGIS extensions for ad-hoc spatial analysis. I generally construct and issue SQL queries by hand from within psql. I always wrap an analysis session within a transaction, so if I issue a destructive query I can roll it back. However, when I issue a query that contains an error, it cancels the transaction. Any further queries elicit the following warning: ERROR: current transaction is aborted, commands ignored until end of transaction block Is there a way I can turn this behaviour off? It is tiresome to rollback the transaction and rerun previous queries every time I make a typo.

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  • NOOB Memory Problem - EXC_BAD_ACCESS

    - by Michael Bordelon
    I have been banging my head against the wall for a couple days and need some help. I have a feeling that I am doing something really silly here, but I cannot find the issue. This is the controller for a table view. I put the SQL in line to simplify it as part of the troubleshooting of this error. Normally, it would be in an accessor method in a model class. It gets through the SQL read just fine. Finds the two objects, loads them into the todaysWorkout array and then builds the cells for the table view. The table view actually comes up on the scree and then it throws the EXC_BAD_ACCESS. I ran instruments and it shows the following: 0 CFString Malloc 1 00:03.765 0x3946470 176 Foundation -[NSPlaceholderString initWithFormat:locale:arguments:] 1 CFString Autorelease 00:03.765 0x3946470 0 Foundation NSRecordAllocationEvent 2 CFString CFRelease 0 00:03.767 0x3946470 0 Bring It -[WorkoutViewController viewDidLoad] 3 CFString Zombie -1 00:03.917 0x3946470 0 Foundation NSPopAutoreleasePool Here is the source code for the controller. I left it all in there just in case there is something extraneous causing the problem. I sincerely appreciate any help I can get: #import "WorkoutViewController.h" #import "MoveListViewController.h" #import "Profile.h" static sqlite3 *database = nil; @implementation WorkoutViewController @synthesize todaysWorkouts; @synthesize woNoteCell; @synthesize bi; //@synthesize woSwitchCell; - (void)viewDidLoad { [super viewDidLoad]; bi = [[BIUtility alloc] init]; todaysWorkouts = [[NSMutableArray alloc] init]; NSString *query; sqlite3_stmt *statement; //open the database if (sqlite3_open([[BIUtility getDBPath] UTF8String], &database) != SQLITE_OK) { sqlite3_close(database); NSAssert(0, @"Failed to opendatabase"); } query = [NSString stringWithFormat:@"SELECT IWORKOUT.WOINSTANCEID, IWORKOUT.WORKOUTID, CWORKOUTS.WORKOUTNAME FROM CWORKOUTS JOIN IWORKOUT ON IWORKOUT.WORKOUTID = CWORKOUTS.WORKOUTID AND DATE = '%@'", [BIUtility todayDateString]]; if (sqlite3_prepare_v2(database, [query UTF8String], -1, &statement, nil) == SQLITE_OK) { while (sqlite3_step(statement) == SQLITE_ROW) { Workout *wo = [[Workout alloc] init]; wo.woInstanceID = sqlite3_column_int(statement, 0); wo.workoutID = sqlite3_column_int(statement, 1); wo.workoutName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(statement, 2)]; [todaysWorkouts addObject:wo]; [wo release]; } sqlite3_finalize(statement); } if(database) sqlite3_close(database); [query release]; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { //todaysWorkouts = [BIUtility todaysScheduledWorkouts]; static NSString *noteCellIdentifier = @"NoteCellIdentifier"; UITableViewCell *cell; if (indexPath.section < ([todaysWorkouts count])) { cell = [tableView dequeueReusableCellWithIdentifier:@"OtherCell"]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier: @"OtherCell"] autorelease]; cell.accessoryType = UITableViewCellAccessoryNone; } if (indexPath.row == 0) { Workout *wo = [todaysWorkouts objectAtIndex:indexPath.section]; [cell.textLabel setText:wo.workoutName]; } else { [cell.textLabel setText:@"Completed?"]; [cell.textLabel setFont:[UIFont fontWithName:@"Arial" size:15]]; [cell.textLabel setTextColor:[UIColor blueColor]]; } } else { cell = (NoteCell *)[tableView dequeueReusableCellWithIdentifier:noteCellIdentifier]; if (cell == nil) { NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"NoteCell" owner:self options:nil]; cell = [nib objectAtIndex:0]; } } return cell; //[cell release]; } - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { NSUInteger row = [indexPath row]; if (indexPath.section < ([todaysWorkouts count]) && (row == 0)) { MoveListViewController *moveListController = [[MoveListViewController alloc] initWithStyle:UITableViewStylePlain]; moveListController.workoutID = [[todaysWorkouts objectAtIndex:indexPath.section] workoutID]; moveListController.workoutName = [[todaysWorkouts objectAtIndex:indexPath.section] workoutName]; moveListController.woInstanceID = [[todaysWorkouts objectAtIndex:indexPath.section] woInstanceID]; NSLog(@"Workout Selected: %@", [[todaysWorkouts objectAtIndex:indexPath.section] workoutName]); Bring_ItAppDelegate *delegate = [[UIApplication sharedApplication] delegate]; [delegate.workoutNavController pushViewController:moveListController animated:YES]; } else { UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath]; if (indexPath.section < ([todaysWorkouts count]) && (row == 1)) { if (cell.accessoryType == UITableViewCellAccessoryNone) { cell.accessoryType = UITableViewCellAccessoryCheckmark; } else { cell.accessoryType = UITableViewCellAccessoryNone; } } } [tableView deselectRowAtIndexPath:indexPath animated:YES]; } - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath { NSInteger h = 35; return h; } - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return ([todaysWorkouts count] + 1); //return ([todaysWorkouts count]); } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { if (section < ([todaysWorkouts count])) { return 2; } else { return 1; } } - (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section { if (section < ([todaysWorkouts count])) { return @"Workout"; } else { return @"How Was Your Workout?"; } } - (void)didReceiveMemoryWarning { // Releases the view if it doesn't have a superview. [super didReceiveMemoryWarning]; // Release any cached data, images, etc that aren't in use. } - (void)viewDidUnload { [super viewDidUnload]; // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; } - (void)dealloc { [todaysWorkouts release]; [bi release]; [super dealloc]; } @end

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  • How to Pass a JS Variable to a PHP Variable

    - by dmullins
    Hello: I am working on a web application that currently provides a list of documents in a MySql database. Each document in the list has an onclick event that is suppose to open the specific document, however I am unable to do this. My list gets popluated using Ajax. Here is the code excerpt (JS): function stateChanged() { if (xmlhttp.readyState==4) { //All documents// document.getElementById("screenRef").innerHTML="<font id='maintxt'; name='title'; onclick='fileopen()'; color='#666666';>" + xmlhttp.responseText + "</font>"; } } } The onclick=fileopen event above triggers the next code excerpt, which downloads the file (JS): function stateChanged() { if (xmlhttp.readyState==4) { //Open file var elemIF = document.createElement("iframe"); elemIF.src = url; elemIF.style.display = "none"; document.body.appendChild(elemIF); } } } Lastly, the openfile onclick event triggers the following php code to find the file for downloading (php): $con = mysql_connect("localhost", "root", "password"); if (!$con) { die('Could not connect: ' . mysql_error()); } mysql_select_db("Documents", $con); $query = mysql_query("SELECT name, type, size, content FROM upload WHERE name = NEED JS VARIABLE HERE"); $row = mysql_fetch_array($query); header ("Content-type: ". $row['type']); header ("Content-length: ". $row['size']); header ("Content-Disposition: attachement; filename=". $row['name']); echo $row['content']; This code works well, for downloading a file. If I omit the WHERE portion of the Sql query, the onclick event will download the first file. Somehow, I need to get the screenRef element text and change it into a variable that my php file can read. Does anyone know how to do this? Also, without any page refreshes. I really appreciate everyone's feedback and thank you in advance. DFM

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  • Problem with truncation of floating point values in DBSlayer.

    - by chrisdew
    When I run a query through DBslayer http://code.nytimes.com/projects/dbslayer the floating point results are truncated to a total of six digits (plus decimal point and negative sign when needed). { ... "lat":52.2228,"lng":-2.19906, ... } When I run the same query in MySQL, the results are as expected. | 52.22280884 | -2.19906425 | Firstly, am I correct in identifying DBSlayer as the cause of this effect? (Or the JSON library it uses, etc.) Secondly, is this floating point precision configurable within DBSlayer? Thanks, Chris. P.S. Ubuntu 9.10, x86_64 Path: . URL: http://dbslayer.googlecode.com/svn/trunk Repository Root: http://dbslayer.googlecode.com/svn Repository UUID: 5df2be84-4748-0410-afd4-f777a056bd0c Revision: 65 Node Kind: directory Schedule: normal Last Changed Author: dgottfrid Last Changed Rev: 65 Last Changed Date: 2008-03-28 22:52:46 +0000 (Fri, 28 Mar 2008)

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  • MySQL Select problems

    - by John Nuñez
    Table #1: qa_returns_items Table #2: qa_returns_residues I have a long time trying to get this Result: item_code - item_quantity 2 - 1 3 - 2 IF qa_returns_items.item_code = qa_returns_residues.item_code AND status_code = 11 THEN item_quantity = qa_returns_items.item_quantity - qa_returns_residues.item_quantity ELSEIF qa_returns_items.item_code = qa_returns_residues.item_code AND status_code = 12 THEN item_quantity = qa_returns_items.item_quantity + qa_returns_residues.item_quantity ELSE show diferendes END IF I tried this Query: select SubQueryAlias.item_code, total_ecuation, SubQueryAlias.item_unitprice, SubQueryAlias.item_unitprice * total_ecuation as item_subtotal, item_discount, (SubQueryAlias.item_unitprice * total_ecuation) - item_discount as item_total from ( select ri.item_code , case status_code when 11 then ri.item_quantity - rr.item_quantity when 12 then ri.item_quantity + rr.item_quantity end as total_ecuation , rr.item_unitprice , rr.item_quantity , rr.item_discount * rr.item_quantity as item_discount from qa_returns_residues rr left join qa_returns_items ri on ri.item_code = rr.item_code WHERE ri.returnlog_code = 1 ) as SubQueryAlias where total_ecuation > 0 GROUP BY (item_code); The query returns this result: item_code - item_quantity 1 - 2 2 - 2

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  • How to work with file and streams in php,case: if we open file in Class A and pass open stream to Cl

    - by Rachel
    I have two class, one is Business Logic Class{BLO} and the other one is Data Access Class{DAO} and I have dependency in my BLO class to my Dao class. Basically am opening a csv file to write into it in my BLO class using inside its constructor as I am creating an object of BLO and passing in file from command prompt: Code: $this->fin = fopen($file,'w+') or die('Cannot open file'); Now inside BLO I have one function notifiy, which call has dependency to DAO class and call getCurrentDBSnapshot function from the Dao and passes the open stream so that data gets populated into the stream. Code: Blo Class Constructor: public function __construct($file) { //Open Unica File for parsing. $this->fin = fopen($file,'w+') or die('Cannot open file'); // Initialize the Repository DAO. $this->dao = new Dao('REPO'); } Blo Class method that interacts with Dao Method and call getCurrentDBSnapshot. public function notifiy() { $data = $this->fin; var_dump($data); //resource(9) of type (stream) $outputFile=$this->dao->getCurrentDBSnapshot($data); // So basically am passing in $data which is resource((9) of type (stream) } Dao function: getCurrentDBSnapshot which get current state of Database table. public function getCurrentDBSnapshot($data) { $query = "SELECT * FROM myTable"; //Basically just preparing the query. $stmt = $this->connection->prepare($query); // Execute the statement $stmt->execute(); $header = array(); while ($row=$stmt->fetch(PDO::FETCH_ASSOC)) { if(empty($header)) { // Get the header values from table(columnnames) $header = array_keys($row); // Populate csv file with header information from the mytable fputcsv($data, $header); } // Export every row to a file fputcsv($data, $row); } var_dump($data);//resource(9) of type (stream) return $data; } So basically in am getting back resource(9) of type (stream) from getCurrentDBSnapshot and am storing that stream into $outputFile in Blo class method notify. Now I want to close the file which I opened for writing and so it should be fclose of $outputFile or $data, because in both the cases it gives me: var_dump(fclose($outputFile)) as bool(false) var_dump(fclose($data)) as bool(false) and var_dump($outputFile) as resource(9) of type (Unknown) var_dump($data) as resource(9) of type (Unknown) My question is that if I open file using fopen in class A and if I call class B method from Class A method and pass an open stream, in our case $data, than Class B would perform some work and return back and open stream and so How can I close that open stream in Class A's method or it is ok to keep that stream open and not use fclose ? Would appreciate inputs as am not very sure as how this can be implemented.

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  • Efficiency of checking for null varbinary(max) column ?

    - by Moe Sisko
    Using SQL Server 2008. Example table : CREATE table dbo.blobtest (id int primary key not null, name nvarchar(200) not null, data varbinary(max) null) Example query : select id, name, cast((case when data is null then 0 else 1 end) as bit) as DataExists from dbo.blobtest Now, the query needs to return a "DataExists" column, that returns 0 if the blob is null, else 1. This all works fine, but I'm wondering how efficient it is. i.e. does SQL server need to read in the whole blob to its memory, or is there some optimization so that it just does enough reads to figure out if the blob is null or not ? (FWIW, the sp_tableoption "large value types out of row" option is set to OFF for this example).

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  • sql server 2005 indexes and low cardinality

    - by Peanut
    How does SQL Server determine whether a table column has low cardinality? The reason I ask is because query optimizer would most probably not use an index on a gender column (values 'm' and 'f'). However how would it determine the cardinality of the gender column to come to that decision? On top of this, if in the unlikely event that I had a million entries in my table and only one entry in the gender column was 'm', would SQL server be able to determine this and use the index to retrieve that single row? Or would it just know there are only 2 distinct values in the column and not use the index? I appreciate the above discusses some poor db design, but I'm just trying to understand how query optimizer comes to its decisions. Many thanks.

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  • Why would I do an inner join on a non-distinct field?

    - by froadie
    I just came across a query that does an inner join on a non-distinct field. I've never seen this before and I'm a little confused about this usage. Something like: SELECT distinct all, my, stuff FROM myTable INNER JOIN myOtherTable ON myTable.nonDistinctField = myOtherTable.nonDistinctField (WHERE some filters here...) I'm not quite sure what my question is or how to phrase it, or why exactly this confuses me, but I was wondering if anyone could explain why someone would need to do an inner join on a non-distinct field and then select only distinct values...? Is there ever a legitimate use of an inner join on a non-distinct field? What would be the purpose? And if there's is a legitimate reason for such a query, can you give examples of where it would be used?

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  • SQL: select random row from table where the ID of the row isn't in another table?

    - by johnrl
    I've been looking at fast ways to select a random row from a table and have found the following site: http://74.125.77.132/search?q=cache:http://jan.kneschke.de/projects/mysql/order-by-rand/&hl=en&strip=1 What I want to do is to select a random url from my table 'urls' that I DON'T have in my other table 'urlinfo'.The query I am using now selects a random url from 'urls' but I need it modified to only return a random url that is NOT in the 'urlinfo' table. Heres the query: SELECT url FROM urls JOIN (SELECT CEIL(RAND() * (SELECT MAX(urlid) FROM urls ) ) AS urlid ) AS r2 USING(urlid); And the two tables: CREATE TABLE urls ( urlid INT NOT NULL AUTO_INCREMENT PRIMARY KEY, url VARCHAR(255) NOT NULL, ) ENGINE=INNODB; CREATE TABLE urlinfo ( urlid INT NOT NULL PRIMARY KEY, urlinfo VARCHAR(10000), FOREIGN KEY (urlid) REFERENCES urls (urlid) ) ENGINE=INNODB;

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  • Does SQL Server Compact Edition (SqlCe) have a SNAPSHOT table like Oracle Lite?

    - by MusiGenesis
    In Oracle Lite, you can create a SNAPSHOT table which is like a normal table except that it tracks changes to itself. The syntax is CREATE SNAPSHOT TABLE tblWhatever ... and you can perform CRUD operations on it like a normal table. To get the change information, you query the table like this: SELECT * FROM tblWhatever + WHERE ... which returns all the rows in the table (including deleted ones) meeting the WHERE clause, and you can access each row's row_state column as a normal field (which is invisible to a normal SELECT * FROM tblWhatever WHERE ... query). Is there some way to do the same thing with Sql Compact Edition (3.5) - i.e. create a table that tracks changes without using RDA?

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  • How can I subsample data from a time series with LINQ to SQL?

    - by Chris Farmer
    I have a database table full of time points and experimental values at those time points. I need to retrieve the values for an experiment and create a thumbnail image showing an XY plot of its data. Because the actual data set for each experiment is potentially 100,000 data points and my image is only 100 pixels wide, I want to sample the data before creating the image. My current query (which retrieves all the data without sampling) is something simple like this: var points = from p in db.DataPoints where p.ExperimentId == myExperimentId orderby p.Time select new { X = p.Time, Y = p.Value } So, how can I best take every nth point from my result set in a LINQ to SQL query?

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  • mysql birthday reminder, leap year

    - by moodh
    Hi, I'm trying to sort out a result set that gives the 5 closest users sorted by upcoming birthday. This works perfectly until leap years comes into play. For example: May 15th - 96 days left May 15th - 97 days left The top result is a birth at 1987 and the lower is from 1988. u_birth is stored as yyyy-mm-dd. Is there a simple way to sort this problem without having to rewrite the entire query? SELECT u_birth, IF( DAYOFYEAR( u_birth ) >= DAYOFYEAR( NOW() ), DAYOFYEAR( u_birth ) - DAYOFYEAR( NOW() ), DAYOFYEAR( u_birth ) - DAYOFYEAR( NOW() ) + DAYOFYEAR( CONCAT( YEAR( NOW() ), '-12-31' ) ) ) AS distance FROM (blog_users) WHERE `s_agehide` = 0 ORDER BY distance ASC LIMIT 5 This query is taken and modified from the mysql manual: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html#c7489

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  • Is it worth caching a Dictionary for foreign key values in ASP.net?

    - by user169867
    I have a Dictionary<int, string> cached (for 20 minutes) that has ~120 ID/Name pairs for a reference table. I iterate over this collection when populating dropdown lists and I'm pretty sure this is faster than querying the DB for the full list each time. My question is more about if it makes sense to use this cached dictionary when displaying records that have a foreign key into this reference table. Say this cached reference table is a EmployeeType table. If I were to query and display a list of employee names and types should I query for EmployeeName and EmployeeTypeID and use my cached dictionary to grab the EmployeeTypeIDs name as each record is displayed or is it faster to just have the DB grab the EmployeeName and JOIN to get the EmployeeType string bypassing the cached Dictionary all together. I know both will work but I'm interested in what will perform the fastest. Thanks for any help.

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  • SQL finding members who are not friends of another member

    - by thedirktastik
    I'm struggling to find a query which will return members who aren't friends of a certain member. Here is the layout of my tables: member_login: MemberID, email, password member_info: memberID, first_name, last_name member_friends: friendID, req_member, req_date, app_member, app_date, date_deactivated I tried to use NOT IN to run a query that would return the opposite of friends but nothing I try seems to be working. Here's what I thought would work: SELECT Mi.First_Name, Mi.Last_Name FROM Member_Info Mi WHERE Mi.Memberid NOT IN( SELECT Mi.Memberid, Mi.First_Name, Mi.Last_Name FROM Member_Info Mi, Member_Login Ml, Member_Friends Mf WHERE Mi.Memberid = Ml.Memberid AND (Mi.Memberid = Mf.Req_Member AND Mf.App_Member = 1 OR Mi.Memberid = Mf.App_Member AND Mf.Req_Member =1) AND Ml.Date_Deactivated <= 0 AND Mf.App_Date > 0 ); Any ideas?

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  • hibernate order by association

    - by Gary Kephart
    I'm using Hibernate 3.2, and using criteria to build a query. I'd like to add and "order by" for a many-to-one association, but I don't see how that can be done. The Hibernate query would end up looking like this, I guess: select t1.a, t1.b, t1.c, t2.dd, t2.ee from t1 inner join t2 on t1.a = t2.aa order by t2.dd <-- need to add this I've tried criteria.addOrder("assnName.propertyName") but it doesn't work. I know it can be done for normal properties. Am I missing something?

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  • Declarative JDOQL vs Single-String JDOQL : performance

    - by DrDro
    When querying with JDOQL is there a performance difference between using the declarative version and the Single-String version: Example from the JDOQL doc: //Declarative JDOQL : Query q = pm.newQuery(org.jpox.Person.class, "lastName == \"Jones\" && age < age_limit"); q.declareParameters("double age_limit"); List results = (List)q.execute(20.0); //Single-String JDOQL : Query q = pm.newQuery("SELECT FROM org.jpox.Person WHERE lastName == \"Jones\"" + " && age < :age_limit PARAMETERS double age_limit"); List results = (List)q.execute(20.0); Other then performance, are there any reasons for which one is better to use then the other or is it just about the one with which we feel more comfortable.

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  • iPhone OSStatus -25308 or errSecInteractionNotAllowed SFHFKeychainUtils

    - by George Octavio
    Hi again guys. I'm trying to access my iPhone's device keychain. I want to access in order to create a simple user-password value intended for a log in function. This is the code I'm using from SFHFKeychainUtils NSArray *keys = [[[NSArray alloc] initWithObjects: (NSString *) kSecClass, kSecAttrService, kSecAttrLabel, kSecAttrAccount, kSecValueData, nil] autorelease]; NSArray *objects = [[[NSArray alloc] initWithObjects: (NSString *) kSecClassGenericPassword, serviceName, serviceName, @"TestUser", @"TestPass", nil] autorelease]; NSDictionary *query = [[[NSDictionary alloc] initWithObjects: objects forKeys: keys] autorelease]; OSStatus status = SecItemAdd((CFDictionaryRef) query, NULL); } else if (status != noErr) { //Output to screen with error code goes here return NO; } return YES; } The error code I'm getting is OSStatus-25308 or errSecInteractionNotAllowed. I'm guessing this means I don't actually have access to my iPhone's keychain? Is there a way to allow access? Thanks for your time.

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  • shift happens videos

    - by hasan
    im sure you guys must have seen the shift happens video series. here's a link to them : http://www.youtube.com/results?search_query=shift+happens&search_type=&aq=f also, the recent hungry beast video about google, which can be found here: (SO doesnt allow new users more than one hyperlink, so please search on youtube for this one) what i'd like to ask you guys is this: is there a program that enables such videos to be made quickly or is it really just the creative genius of the respective authors? i think vidoes like these are extremely useful when you want to make an impact and would find many uses for such a program in my line of work. im hoping somebody can point me in the right direction. ps. i DO know of animoto, so please dont suggest that :P the problem with animoto is that it doesnt allow text manipulation like these videos. to be fair, that is a great product in itself, but im sure if you take a look, you'll see the difference that im talking abuot.

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  • dilemma about mysql. using condition to limit load on a dbf

    - by ondrobaco
    hi, I have a table of about 800 000 records. Its basically a log which I query often. I gave condition to query only queries that were entered last month in attempt to reduce the load on a database. My thinking is a) if the database goes only through the first month and then returns entries, its good. b) if the database goes through the whole database + checking the condition against every single record, it's actually worse than no condition. What is your opinion? How would you go about reducing load on a dbf?

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  • Essential skills of a Data Scientist

    - by harshsinghal
    I would like to know more about the relevant skills in the arsenal of a Data Scientist, and with new technologies coming in every day, how one picks and chooses the essentials. A few ideas germane to this discussion: Knowing SQL and the use of a DB such as MySQL, PostgreSQL was great till the advent of NoSql and non-relational databases. MongoDB, CouchDB etc. are becoming popular to work with web-scale data. Knowing a stats tool like R is enough for analysis, but to create applications one may need to add Java, Python, and such others to the list. Data now comes in the form of text, urls, multi-media to name a few, and there are different paradigms associated with their manipulation. What about cluster computing, parallel computing, the cloud, Amazon EC2, Hadoop ? OLS Regression now has Artificial Neural Networks, Random Forests and other relatively exotic machine learning/data mining algos. for company Thoughts?

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  • SQL joins "going up" two tables

    - by blcArmadillo
    I'm trying to create a moderately complex query with joins: SELECT `history`.`id`, `parts`.`type_id`, `serialized_parts`.`serial`, `history_actions`.`action`, `history`.`date_added` FROM `history_actions`, `history` LEFT OUTER JOIN `parts` ON `parts`.`id` = `history`.`part_id` LEFT OUTER JOIN `serialized_parts` ON `serialized_parts`.`parts_id` = `history`.`part_id` WHERE `history_actions`.`id` = `history`.`action_id` AND `history`.`unit_id` = '1' ORDER BY `history`.`id` DESC I'd like to replace `parts`.`type_id` in the SELECT statement with `part_list`.`name` where the relationship I need to enforce between the two tables is `part_list`.`id` = `parts`.`type_id`. Also I have to use joins because in some cases `history`.`part_id` may be NULL which obviously isn't a valid part id. How would I modify the query to do this?

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  • How to model a social news feed on Google App Engine

    - by PEZ
    We want to implement a "News feed" where a user can see messages broadcasted by her friends, sorted with newest message first. But the feed should reflect changes in her friends list. (If she adds new friends, messages from those should be included in the feed, and if she removes friends their messages should not be included.) If we use the pubsub-test example and attach a recipient list to each message this means a lot of manipulation of the message recipients lists when users connect and disconnect friends. We first modeled publish-subscribe "fan out" using conventional RDBMS thinking. It seemed to work at first, but then, since the IN operator works the way it does, we quickly realized we couldn't continue on that path. We found Brett Slatkin's presentation from last years Google I/O and we have now watched it a few times but it isn't clear to us how to do it with "dynamic" recipient lists. What we need are some hints on how to "think" when modeling this.

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  • How do I limit the permissions of a C# program to read only on an SQLServer Database?

    - by gav
    Hi Guys, I have written some C# which connects to a live production database. I want to give my application read only access to the DB but am unsure how to achieve this. Is there any trivial way to get this done by amending the connection string? My understanding is that the application will logon with the credentials of the person running the application and hence may or may not have write access to the db based on that fact. Can I statically limit the permissions of the application so that if someone changes the program to do something devastating at a later date any manipulation will fail? Apologies for how trivial the question may be but it's my first venture into the world of MS programming. Thanks, Gav

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  • ORDER BY giving wrong order

    - by Cody Dull
    I have an SQL statement in my C# program that looks like: SELECT * FROM XXX.dbo.XXX WHERE Source = 'OH' AND partnum = '1231202085' ORDER BY partnum, Packaging, Quantity When running this query in SQL Server Management, the results are ordered as expected. My first 3 results have the same partnum and Packaging with Quantities of 32.0, 50.8, and 51.0. However, when I run the query from my program, the result set with quantity 50.8 is the first to be returned. The datatype of Quantity is decimal(18,9). I've tried cast, it doesn't appear to be a datatype problem. I cant figure out why its getting the middle quantity.

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