Search Results

Search found 6988 results on 280 pages for 'if statement'.

Page 191/280 | < Previous Page | 187 188 189 190 191 192 193 194 195 196 197 198 | Next Page >

What's the right way to handle "One, Both, or None" logic?

- by Stephen

I have a logic situation that is best described as two "Teams" trying to win a task. The outcome of this task could be a single winner, a tie (draw), or no winner (stalemate). Currently, I'm using a nested if/else statement like so: // using PHP, but the concept seems language agnostic. if ($team_a->win()) { if ($team_b->win()) { // this is a draw } else { // team_a is the winner } } else { if ($team_b->win()) { // team_b is the winner } else { // This is a stalemate, no winner. } } This seems rather spaghetti-like and repetitive. Is there a more logical, DRY pattern I could use?

Read the article
Linear time and quadratic time

- by jasonline

I'm just not sure... If you have a code that can be executed in either of the following complexities: (1) A sequence of O(n), like for example: two O(n) in sequence (2) O(n²) The preferred version would be the one that can be executed in linear time. Would there be a time such that the sequence of O(n) would be too much and that O(n²) would be preferred? In other words, is the statement C x O(n) < O(n²) always true for any constant C? If no, what are the factors that would affect the condition such that it would be better to choose the O(n²) complexity?

Read the article
Weird behavior in referring to global variable. Is this a bug in javascript? Surely it isn't!

- by Chandan .

Consider the following piece of code. <html> <body> <script> var x = 5; //globally declared function showX() { alert("x="+x); //trying to display global value var x=10; //trying to create and initialize a local x } </script> <input type = "button" value="Show X" onclick="showX()"> </body> </html> The alert statement shows 'x=undefined'. And doesn't print the global value of x as expected. An equivalent java code would display 5! So, is it a bug? If not then how does one explain that behavior?

Read the article
How do you handle options that can't be used together with OptionParser?

- by Joel

My Python script (for todo lists) is started from the command line like this: todo [options] <command> [command-options] Some options can not be used together, for example todo add --pos=3 --end "Ask Stackoverflow" would specify both the third position and the end of the list. Likewise todo list --brief --informative would confuse my program about being brief or informative. Since I want to have quite a powerful option control, cases like these will be a bunch, and new ones will surely arise in the future. If a users passes a bad combination of options, I want to give an informative message, preferably along with the usage help provided by optparse. Currently I handle this with an if-else statement that I find really ugly and poor. My dream is to have something like this in my code: parser.set_not_allowed(combination=["--pos", "--end"], message="--pos and --end can not be used together") and the OptionParser would use this when parsing the options. Since this doesn't exist as far as I know, I ask the SO community: How do you handle this?

Read the article
Hide or Disable? In this example and in general...

- by George

I have the following set of controls. Scenario 1: If you select one of the first 3 radio buttons and click enter, focus will jump to the Passport Number text box. If the user selects "Other", the "Other, Please Specify" textbox is enabled and, for convenience, screen focus (the cursor is moved) to that textbox. Scenario 2: The "specify Other" text box is hidden until the user clicks on the Other Radio button. Upon doing so, the textbox is made visible and the cursor is placed in this textbox. Which scenario do you feel is a better approach? Perhaps you have another variation? Please state your reasoning. I would also appreciate it if you could make a generalized statement as to when hiding is better than disabling or vice versa, but I am also interested in this particular example. Thanks. Afetrthought: Perhaps, in the 2nd example, the "Please Specify" text would only appear after the user has selected the 'Other' radio button.

Read the article
Getting a NullReferenceException Error when invoking a Select File Dialog Box

- by codingguy3000

Hey everyone This is a real newbie question. I have simple app that selects a picture and display's that picture in a PictureBox. I decided to mess with the Opacity Attribute so I added a timer and created this cool effect where the Main Form's Opacity is increased by 20% every 400 miliseconds. The problem is that now when I click the button that invokes the Select File Dialog Box I'm getting a NullReferenceException error. private void tmrClock_Tick(object sender, EventArgs e) { if (ViewerForm.ActiveForm.Opacity != 1) { ActiveForm.Opacity = ActiveForm.Opacity + .20; } } The error message is pointing to the if statement. What am I doing wrong? Thanks

Read the article
Newbie SQL joining question: houses, refrigerators, and apples

- by Philip Brocoum

There are three tables in my database: apples, refrigerators, and houses. Each apple belongs to a refrigerator (it has a column that references the refrigerator that it's in), and each refrigerator belongs to a house. The problem is, each apple ALSO belongs to a house. I guess this isn't "normalized" or whatever, but it's the way it is. Obviously, each apple should belong to the house that its refrigerator belongs to. An apple can't be in two different places at once, after all. So, my question is this: what SQL statement will allow me to find all of the "bad apples" that for some reason incorrectly reference a different house than the refrigerator that they are supposedly in. In other words, I need to find the apples that contain contradictory information. I don't know if this is a "join" question or not, but I'm sure there's probably a very straightforward way of figuring this out. I just don't know what it is. Thanks for your help!

Read the article
Simple XML parsing error

- by phpeffedup

I'm trying to iterate through a Twitter XML File, where the container tag is , and each user is . I need to create a variable $id based on the XML attribute for each user. Username is already instantiated. $url = "http://api.twitter.com/1/statuses/friends/$username.xml"; $xmlpure = file_get_contents($url); $listxml = simplexml_load_string($xmlpure); foreach($listxml->users->children() as $child) { $id = $child->{"id"}; //Do another action } But I'm getting this error: Warning: main() [function.main]: Node no longer exists in /home/.../bonus.php on line 32 Line 32 is the foreach statement, and I don't actually USE the main() method. What am I doing wrong?

Read the article
Does <T> need to be imported as a class for this to work?

- by zxc

In order for this to work, do you have to have an import statement for the T class? private static <T> void invertOrdering(List<T> list) { for (int i = 0; i < list.size() / 2; i++) { int j = list.size() - 1 - i; T item1 = list.get(i); T item2 = list.get(j); list.set(i, item2); list.set(j, item1); } }

Read the article
Improving MySQL Update Query Efficiency

- by Russell C.

In our database tables we keep a number of counting columns to help reduce the number of simple lookup queries. For example, in our users table we have columns for the number of reviews written, photos uploaded, friends, followers, etc. To help make sure these stay in sync we have a script that runs periodically to check and update these counting columns. The problem is that now that our database has grown significantly the queries we have been using are taking forever to run since they are totally inefficient. I would appreciate someone with more MySQL knowledge than myself to recommend how we can improve it's efficiency: update users set photos=(select count(*) from photos where photos.status="A" AND photos.user_id=users.id) where users.status="A"; If this were a select statement I would just use a join but I'm not sure if that is possible with update. Thanks in advance for your help!

Read the article
How to insert an n:m-relationship with technical primary keys generated by a sequence?

- by bitschnau

Let's say I have two tables with several fields and in every table there is a primary key which is a technical id generated by a database sequence: table1 table2 ------------- ------------- field11 <pk> field21 <pk> field12 field22 field11 and field21 are generated by sequences. Also there is a n:m-relationship between table1 und table2, designed in table3: table3 ------------- field11 <fk> field21 <fk> The ids in table1 und table2 are generated during the insert statement: INSERT INTO table1 VALUES (table1_seq1.NEXTVAL, ... INSERT INTO table2 VALUES (table2_seq1.NEXTVAL, ... Therefore I don't know the primary key of the added row in the data-access-layer of my program, because the generation of the pk happens completely in the database. What's the best practice to update table3 now? How can I gain access to the primary key of the rows I just inserted?

Read the article
Read a file with 2048 bytes

- by Suresh S

Guys i have a file which has only one line. The file has no encoding it is a simple text file with single line. For every 2048 byte in a line , there is new record of 151 byte (totally 13*151 byte = 1945 records + 85 byte empty space). similarly for the next 2048 bytes. What is the best file i/o to use? i am thinking of reading 2048 bytes from file and storing it in an array . while (offset < fileLength &&(numRead=in.read(recordChunks, offset,alength)) >= 0) { } how can i get from the read statement only 2048 bytes at a time . i am getting IndexOutofBoundException.

Read the article
SQL - suppressing duplicate *adjacent* records

- by Trevel

I need to run a Select statement (DB2 SQL) that does not pull adjacent row duplicates based on a certain field. In specific, I am trying to find out when data changes, which is made difficult because it might change back to its original value. That is to say, I have a table that vaguely resembles: A, 5, Jan A, 12, Feb A, 12, Mar A, 12, Apr A, 9, May A, 9, Jun A, 5, Jul And I want to get the results: A, 5, Jan A, 12, Feb A, 9, May A, 5, Jul discarding adjacent duplicates but keeping the last row. The obvious: Select Letter, Number, Min(Month) from Table group by Letter, Number does not work -- it doesn't include the last row.

Read the article
Why did the C# designers attach three different meanings to the 'using' keyword?

- by gWiz

The using keyword has three disparate meanings: type/namespace aliasing namespace import syntactic sugar for ensuring Dispose is called The documentation calls the first two definitions directives (which I'm guessing means they are preprocessing in nature), while the last is a statement. Regardless of the fact that they are distinguished by their syntaxes, why would the language developers complicate the semantics of the keyword by attaching three different meanings to it? For example, (disclaimer: off the top of my head, there may certainly be better examples) why not add keywords like alias and import? Technical, theoretical, or historical reasons? Keyword quota? ;-) Contrived sample: import System.Timers; alias LiteTimer=System.Threading.Timer; alias WinForms=System.Windows.Forms; public class Sample { public void Action { var elapsed = false; using(var t = new LiteTimer.Timer(_ => elapsed = true) { while (!elapsed) CallSomeFinickyApi(); } } } "Using" is such a vague word.

Read the article
select subquery cause mysql server to be unresponsive

- by Xiao

DELETE FROM item_measurement WHERE measurement_id IN ( SELECT (-id) AS measurement_id FROM invoice_item WHERE invoice_id = 'A3722' ) I've really tried hard to find what's wrong with the code. I tried to run this in a php page, which doesn't respond. I also tried the same line in phpmyadmin, infinite spinning circle and I had to restart the server(MAMP on Mac 10.9). No error was given in browser/ If I run the delete and select separately, they both finish very quickly. I don't think it's a performance issue because the separate run took < 0.1 sec each. Thanks for any help in advance. Edit: I also found that a simple select statement will also suspend mysql: select * from item_measurement where measurement_id in (select -id from invoice_item where invoice_id='A3722')

Read the article
Copy Data from One SQL Server Table to Other in Same Database Without Specifying Columns

- by Scott

In SQL Server there is the ability to INSERT all of the data from one table into another using the following statement: INSERT INTO TABLE1 SELECT * FROM TABLE2 When running this on a table with an identity column, even though we have run the command SET IDENTITY_INSERT TABLE1 ON, we get the error: An explicit value for the identity column in table can only be specified when a column list is used and IDENTITY_INSERT is ON This implies that we would have to list off all of the columns within the INSERT in order for this to work properly. In the situation that we are in, we do not have access to the column names, only the list of the tables we need to copy over. Is there any way to get around this limitation?

Read the article
Best way to handle enable/disable of UIButtons on iPhone

- by Anonymous

I have an increase button and a decrease button, both of which affect a variable. The variable has a minimum and the decrease button will be disabled once that minimum is reached. Likewise for the maximum value of the variable. In my controller, I have two IBActions for both the increase and decrease actions, and two IBOutlets, in order to disable the buttons accordingly. At the bottom of my KVO statement to handle the value change, I have: increaseButton.enabled = value != MAX; decreaseButton.enabled = value != MIN; While this code is functional, I can't help but feel that feel this is a naive approach to the problem, especially since this requires 4 connections. Is there a better solution to this, one that uses fewer connections?

Read the article
How to use Externel Triggers on Oracle 11g..

- by RBA

Hi, I want to fire a trigger whenever an insert command is fired.. The trigger will access a pl/sql file which can change anytime.. So the query is, if we design the trigger, how can we make sure this dynamic thing happens.. As during the stored procedure, it is not workingg.. I think - it should work for 1) External Procedures 2) Execute Statement Please correct me, if I am wrong.. I was working on External Procedures but i am not able to find the way to execute the external procedure from here on.. SQL> CREATE OR REPLACE FUNCTION Plstojavafac_func (N NUMBER) RETURN NUMBER AS 2 LANGUAGE JAVA 3 NAME 'Factorial.J_calcFactorial(int) return int'; 4 / @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ SQL> CREATE OR REPLACE TRIGGER student_after_insert 2 AFTER INSERT 3 ON student 4 FOR EACH ROW How to call the procedure from heree... And does my interpretations are right,, plz suggest.. Thanks.

Read the article
Python: Time a code segment for testing performance (with timeit)

- by Mestika

Hi, I've a python script which works just as it should but I need to write the time for the execution. I've gooled that I should use timeit but I can't seem to get it to work. My Python script looks like this: import sys import getopt import timeit import random import os import re import ibm_db import time from string import maketrans myfile = open("results_update.txt", "a") for r in range(100): rannumber = random.randint(0, 100) update = "update TABLE set val = %i where MyCount >= '2010' and MyCount < '2012' and number = '250'" % rannumber #print rannumber conn = ibm_db.pconnect("dsn=myDB","usrname","secretPWD") for r in range(5): print "Run %s\n" % r ibm_db.execute(query_stmt) query_stmt = ibm_db.prepare(conn, update) myfile.close() ibm_db.close(conn) What I need it the time it takes the execution of the query and written to the file "results_update.txt". The purpose is to test an update statement for my database with different indexes and tuning mechanisms. Sincerely Mestika

Read the article
Regarding Shell variable

- by arav

I need to call another shell script testarg.sh within my main script. This script testarg.sh has arguments ARG1 ,ARG2, ARG3. I need to call up the below way ./testarg.sh -ARG1 -ARG2 -ARG3 ARG1 and ARG3 argument Variables are mandatory ones. If its not passed to the main script then i quit. ARG2 is an optional one. If the ARG2 variable is not set with value or it's not defined then i need not pass it from main script.So i need to call up the below way ./testarg.sh -ARG1 -ARG3 If the value exist for the ARG2 Varibale then i need to call the below way ./testarg.sh -ARG1 -ARG2 -ARG3 Do i need to have a if else statement for checking the ARG2 variable is empty or null. Is there any other way to do it.

Read the article
SQL query to select distinct record with 2 or more repetition in another field

- by kyohiros

So I have this table of book orders, it contains 2 columns, one is the order ID(primary key) and another is the ID of the book that the customer ordered. For example: | OrderID | BookID | | 0001 | B002 | | 0002 | B005 | | 0003 | B002 | | 0004 | B003 | | 0005 | B005 | | 0006 | B002 | | 0007 | B002 | What I want is to get the IDs of the books that got 2 or more purchases/orders, for example if I run the SQL query against the above data, I would get this as the result: | BookID | | B002 | | B005 | I don't know if this can be archived in SQL or I have to built a simpler statement and repetitive run the query against all the records in another language. I need some help and thanks for reading my question.

Read the article
Zend Database Adapter - Complex MySQL Query

- by Sonny

I have defined a function in my Navigation model that executes a query, and I was wondering if there's a more "Zendy" way of generating/executing the query. The query I'm using was proposed by Bill Karwin on another thread here for setting arbitrary record order. I tried using a prepared statement, but the values in the SIGN() function got quoted. I'm using the PDO adapter for MySQL. /** * */ public function setPosition($parentId, $oldPosition, $newPosition) { $parentId = intval($parentId); $oldPosition = intval($oldPosition); $newPosition = intval($newPosition); $this->getAdapter()->query(" UPDATE `navigation` SET `position` = CASE `position` WHEN $oldPosition THEN $newPosition ELSE `position` + SIGN($oldPosition - $newPosition) END WHERE `parent_id` = $parentId AND `position` BETWEEN LEAST($oldPosition, $newPosition) AND GREATEST($oldPosition, $newPosition) "); return $this; }

Read the article
Extracting methods body from a class of Java Source Code

- by Muhammad Asaduzzaman

Hi, I want to extract method body from a Java Source Code. Suppose I have the following code: public class A{ public void print(){ System.out.println("Print This thing"); System.out.println("Print This thing"); System.out.println("Print This thing"); } } My objective is not to extract the method name (in this case print) but also the bode of the method(In this case the three print statement inside the print method). Can anyone suggest how can I do so? Is their any library available for doing so.

Read the article
sqrt(int_value + 0.0) ? The point?

- by Earlz

Hello, while doing some homework in my very strange C++ book, which I've been told before to throw away, had a very peculiar code segment. I know homework stuff always throws in extra "mystery" to try to confuse you like indenting 2 lines after a single-statement for-loop. But this one I'm confused on because it seems to serve some real-purpose. basically it is like this: int counter=10; ... if(pow(floor(sqrt(counter+0.0)),2) == counter) ... I'm interested in this part especially: sqrt(counter+0.0) Is there some purpose to the +0.0? Is this the poormans way of doing a static cast to a double? Does this avoid some compiler warning on some compiler I do not use? The entire program printed the exact same thing and compiled without warnings on g++ whenever I left out the +0.0 part. Maybe I'm not using a weird enough compiler?

Read the article
Use a named custom column in SQL 2005 in WHERE clause?

- by Orange Kid

Can I name a custom column in the SELECT statement and reference that in the WHERE clause without duplicating code? For example; SELECT RIGHT(REPLICATE('0', 5) + RTRIM(SOME_ID)), 5) AS DISPLAY_ID FROM dbo.MY_TABLE WHERE DISPLAY_ID LIKE '%005%' Only much more complicated. I want to maintain this code in one place only but SQL Server 2005 forces me to duplicate the custom SELECT in the WHERE clause. I believe this was possible in Microsoft SQL Server 2000 but no longer in 2005. Thanks.

Read the article

< Previous Page | 187 188 189 190 191 192 193 194 195 196 197 198 | Next Page >