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• MySQL 5.5.8 Gets Periodic Lag

  - by CYREX

  Am using MySQL 5.5.8 on an Ubuntu system and every X amount of time it creates a huge lag that lasts a couple of seconds. Then all goes back to normal until the next lag. The time period varies but it looks like it happen periodically. Am using InnoDB. It is like hiccups in the MySQL. What could be creating this sort of periodic problem. Do not have any cron jobs or process running every time the X period happens. The X period could be between 30 minutes to 2 hours. So for example it could happen every 30 minutes for the next 12 hours or it could happen every 2 hours for the next 8 hours. key_buffer_size = 256M max_allowed_packet = 1M table_cache = 1024 table_open_cache = 1024 sort_buffer_size = 2M read_buffer_size = 2M read_rnd_buffer_size = 4M myisam_sort_buffer_size = 32M thread_cache_size = 128 query_cache_size= 128M log-slow-queries = slow.log long_query_time = 5 log-queries-not-using-indexes # Try number of CPU's*2 for thread_concurrency thread_concurrency = 4 max_connections=512 #innodb_data_file_path = ibdata1:10M:autoextend #innodb_log_group_home_dir = /usr/local/mysql/data # You can set .._buffer_pool_size up to 50 - 80 % # of RAM but beware of setting memory usage too high innodb_buffer_pool_size = 1G #innodb_additional_mem_pool_size = 20M # Set .._log_file_size to 25 % of buffer pool size #innodb_log_file_size = 64M #innodb_log_buffer_size = 8M #innodb_flush_log_at_trx_commit = 0 #innodb_lock_wait_timeout = 50 [mysqldump] quick max_allowed_packet = 16M [myisamchk] key_buffer_size = 64M sort_buffer_size = 64M read_buffer = 2M write_buffer = 2M There are about 200+ tables divided in 3 databases. The most written too is in InnoDB. The other ones are more read. Several of the tables in the InnoDB have more than 2 million records. The other databases top at about 400 thousand records and do not change so often. The PC is a Core 2 Duo 8400 with 4GB RAM, 32Bit Ubuntu.

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• Codeigniter Inserting Multidimensional Array as rows in MySQL

  - by RisingSun

  Please Refer to this question I asked Codeigniter Insert Multiple Rows in SQL To restate <tr> <td><input type="text" name="user[0][name]" value=""></td> <td><input type="text" name="user[0][address]" value=""><br></td> <td><input type="text" name="user[0][age]" value=""></td> <td><input type="text" name="user[0][email]" value=""></td> </tr> <tr> <td><input type="text" name="user[1][name]" value=""></td> <td><input type="text" name="user[1][address]" value=""><br></td> <td><input type="text" name="user[1][age]" value=""></td> <td><input type="text" name="user[1][email]" value=""></td> </tr> .......... Can Be Inserted into MySQL as this foreach($_POST['user'] as $user) { $this->db->insert('mytable', $user); } This results in multiple MySQL queries. Is it possible to optimise it further, so that the insert occurs in one query Something like this insert multiple rows via a php array into mysql but taking advantage of codeigniters simpler syntax. Thanks

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• Reduce durability in MySQL for performance

  - by Paul Prescod

  My site occasionally has fairly predictable bursts of traffic that increase the throughput by 100 times more than normal. For example, we are going to be featured on a television show, and I expect in the hour after the show, I'll get more than 100 times more traffic than normal. My understanding is that MySQL (InnoDB) generally keeps my data in a bunch of different places: RAM Buffers commitlog binary log actual tables All of the above places on my DB slave This is too much "durability" given that I'm on an EC2 node and most of the stuff goes across the same network pipe (file systems are network attached). Plus the drives are just slow. The data is not high value and I'd rather take a small chance of a few minutes of data loss rather than have a high probability of an outage when the crowd arrives. During these traffic bursts I would like to do all of that I/O only if I can afford it. I'd like to just keep as much in RAM as possible (I have a fair chunk of RAM compared to the data size that would be touched over an hour). If buffers get scarce, or the I/O channel is not too overloaded, then sure, I'd like things to go to the commitlog or binary log to be sent to the slave. If, and only if, the I/O channel is not overloaded, I'd like to write back to the actual tables. In other words, I'd like MySQL/InnoDB to use a "write back" cache algorithm rather than a "write through" cache algorithm. Can I convince it to do that? If this is not possible, I am interested in general MySQL write-performance optimization tips. Most of the docs are about optimizing read performance, but when I get a crowd of users, I am creating accounts for all of them, so that's a write-heavy workload.

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• Indexing table with duplicates MySQL/MSSQL with millions of records

  - by Tesnep

  I need help in indexing in MySQL. I have a table in MySQL with following rows: ID Store_ID Feature_ID Order_ID Viewed_Date Deal_ID IsTrial The ID is auto generated. Store_ID goes from 1 - 8. Feature_ID from 1 - let's say 100. Viewed Date is Date and time on which the data is inserted. IsTrial is either 0 or 1. You can ignore Order_ID and Deal_ID from this discussion. There are millions of data in the table and we have a reporting backend that needs to view the number of views in a certain period or overall where trial is 0 for a particular store id and for a particular feature. The query takes the form of: select count(viewed_date) from theTable where viewed_date between '2009-12-01' and '2010-12-31' and store_id = '2' and feature_id = '12' and Istrial = 0 In MSSQL you can have a filtered index to use for Istrial. Is there anything similar to this in MySQL? Also, Store_ID and Feature_ID have a lot of duplicate data. I created an index using Store_ID and Feature_ID. Although this seems to have decreased the search period, I need better improvement than this. Right now I have more than 4 million rows. To search for a particular query like the one above, it looks at 3.5 million rows in order to give me the count of 500k rows. PS. I forgot to add view_date filter in the query. Now I have done this.

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• Error when feeding a mysql db with a python-parsed data

  - by Barnabe

  I use this bit of code to feed some data i have parsed from a web page to a mysql database c=db.cursor() c.executemany( """INSERT INTO data (SID, Time, Value1, Level1, Value2, Level2, Value3, Level3, Value4, Level4, Value5, Level5, ObsDate) VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)""", clean_data ) The parsed data looks like this (there are several hundred such lines) clean_data = [(161,00:00:00,8.19,1,4.46,4,7.87,4,6.54,null,4.45,6,2010-04-12),(162,00:00:00,7.55,1,9.52,1,1.90,1,4.76,null,0.14,1,2010-04-12),(164,00:00:00,8.01,1,8.09,1,0,null,8.49,null,0.20,2,2010-04-12),(166,00:00:00,8.30,1,4.77,4,10.99,5,9.11,null,0.36,2,2010-04-12)] if i hard code the data as above mySQL accepts my request (except for some quibbles about formatting) but if the variable clean_data is instead defined as the result of the parsing code, like this: cleaner = [(""" $!!'""", ')]'),(' $!!', ') etc etc] def processThis(str,lst): for find, replace in lst: str = str.replace(find, replace) return str clean_data = processThis(data,cleaner) then i get the dreaded "TypeError: not enough arguments for format string" After playing with formatting options for a few hours (I am very new to this) I am confused... what is the difference between the hard coded data and the result of the processThis function as fas as mySQL is concerned? Any idea greatly appreciated...

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• Stable/repeatable random sort (MySQL, Rails)

  - by Matt Rogish

  I'd like to paginate through a randomly sorted list of ActiveRecord models (rows from MySQL database). However, this randomization needs to persist on a per-session basis, so that other people that visit the website also receive a random, paginate-able list of records. Let's say there are enough entities (tens of thousands) that storing the randomly sorted ID values in either the session or a cookie is too large, so I must temporarily persist it in some other way (MySQL, file, etc.). Initially I thought I could create a function based on the session ID and the page ID (returning the object IDs for that page) however since the object ID values in MySQL are not sequential (there are gaps), that seemed to fall apart as I was poking at it. The nice thing is that it would require no/minimal storage but the downsides are that it is likely pretty complex to implement and probably CPU intensive. My feeling is I should create an intersection table, something like: random_sorts( sort_id, created_at, user_id NULL if guest) random_sort_items( sort_id, item_id, position ) And then simply store the 'sort_id' in the session. Then, I can paginate the random_sorts WHERE sort_id = n ORDER BY position LIMIT... as usual. Of course, I'd have to put some sort of a reaper in there to remove them after some period of inactivity (based on random_sorts.created_at). Unfortunately, I'd have to invalidate the sort as new objects were created (and/or old objects being removed, although deletion is very rare). And, as load increases the size/performance of this table (even properly indexed) drops. It seems like this ought to be a solved problem but I can't find any rails plugins that do this... Any ideas? Thanks!!

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• Require reasonably random results from an SQL SELECT query within a Joomla article (Cache enabled)

  - by Shrinivas

  Setup: Joomla website on LAMP stack I have a MySQL table containing some records, these are queried by a simple SELECT on the Joomla article, as pasted below. This specific Joomla website has Caching turned on in Joomla's Global Configuration. I need to randomize the order in which I display the resultset, each time the page is loaded. Regular php/mysql would offer me two approaches for this: 1. use 'order by RAND()' or any of a number of methods to allow a SELECT query to return reasonably random results. 2. once php gets the result from the SELECT into an array, shuffle the array to get a reasonably random order of array items. However, as this Joomla instance has Caching turned ON in its Global Configuration, either of the above approaches fails. The first time I load the page the order is randomized, however any further reloads do not cause the order to change, as the page is delivered from cache. The instant the Cache is disabled, both approaches (shuffle/order by rand) work perfectly. What am I missing? How do I override the Global Cache for this specific article? A very simple requirement, that is met by both php and mysql reasonably well, is blocked by the Joomla Cache that I cannot turn off. The php that returns results from the database. <pre> $db = JFactory::getDBO(); $select = "SELECT id FROM jos_mytable;"; //order by RAND() $db->setQuery($select); echo $db->getQuery(); //Show me the Query! $rows = $db->loadObjectList(); //shuffle($rows); foreach($rows as $row) { echo "$row->id"; }

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• trying to backup mysql database using php

  - by user225269

  I got this code from this site: http://www.php-mysql-tutorial.com/wikis/mysql-tutorials/using-php-to-backup-mysql-databases.aspx But I'm just a beginner so I don't know what the config.php and opendb.php suppose to mean. Do I have to create those 2 files in order for this code to work? If yes, then how do I create it, it isn't included in the site how to create it. <?php include 'config.php'; include 'opendb.php'; $tableName = 'mypet'; $backupFile = 'backup/mypet.sql'; $query = "SELECT * INTO OUTFILE '$backupFile' FROM $tableName"; $result = mysql_query($query); include 'closedb.php'; ?> can I just include these lines on the top code so that I will not be putting the include 'opendb.php' anymore: $con = mysql_connect("localhost","root",""); if (!$con) { die('Could not connect: ' . mysql_error()); } mysql_select_db("Hospital", $con);

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• XAMPP, MAMP, MySQL, PDO - A deadly combination?

  - by Rich

  Hey folks, Previously I've worked on a Symfony project (MySQL PDO based) with XAMPP, with no problems. Since then, I've moved to MAMP - I prefer this - but have hit a snag with my database connection. I've created a test.php like this: <?php try { $dbh = new PDO('mysql:host=localhost;dbname=xxx;port=8889', 'xxx', 'xxx'); foreach($dbh->query('SELECT * from FOO') as $row) { print_r($row); } $dbh = null; } catch (PDOException $e) { print "Error!: " . $e->getMessage() . "<br/>"; die(); } ?> Obviously the *xxx*s are real db connection details. Which when served by MAMP seems to work fine. From terminal however I keep getting the following error when running the file: Error!: SQLSTATE[28000] [1045] Access denied for user 'xxx'@'localhost' (using password: YES) Not sure if the terminal is aiming at a different MySQL socket or something along those lines; but I've tried pointing it to the MAMP socket with a local php.ini file. Any help would be greatly appreciated.

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• how to delete in Mysql

  - by Ian Moss

  i want to delete a element in mysql. the problem is that my connection not succesfully open and they give me error unable to connect even same connectionstring work elsewhere in current project. well when my code open the connection they work fine. but a small function try to delete a row in Mysql. i am confused what is goes wrong because :- same connectionstring work elsewhere in project i trying but a function only have a project [unable to connect] the [unable to connect] problem come when my code trying to delete the rows in mysql. i use sqlyog to open the connection and they work fine as other code work and their is no problem i got when i run the command on sqlyog. conclusion:- why connection not open if they work elsewhere in the project and in also in sqlyog. any reason for unable to connect. because connection can not open offcourse command never run so what is reason upon the connection unable to connect. well any suggestion , thing you feel and trick you have to solve this issue i have. thanks

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• Indexing table with duplicates MySQL/SQL Server with millions of records

  - by Tesnep

  I need help in indexing in MySQL. I have a table in MySQL with following rows: ID Store_ID Feature_ID Order_ID Viewed_Date Deal_ID IsTrial The ID is auto generated. Store_ID goes from 1 - 8. Feature_ID from 1 - let's say 100. Viewed Date is Date and time on which the data is inserted. IsTrial is either 0 or 1. You can ignore Order_ID and Deal_ID from this discussion. There are millions of data in the table and we have a reporting backend that needs to view the number of views in a certain period or overall where trial is 0 for a particular store id and for a particular feature. The query takes the form of: select count(viewed_date) from theTable where viewed_date between '2009-12-01' and '2010-12-31' and store_id = '2' and feature_id = '12' and Istrial = 0 In SQL Server you can have a filtered index to use for Istrial. Is there anything similar to this in MySQL? Also, Store_ID and Feature_ID have a lot of duplicate data. I created an index using Store_ID and Feature_ID. Although this seems to have decreased the search period, I need better improvement than this. Right now I have more than 4 million rows. To search for a particular query like the one above, it looks at 3.5 million rows in order to give me the count of 500k rows. PS. I forgot to add view_date filter in the query. Now I have done this.

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• Print table data mysql php

  - by Marcelo

  Hi people, i'm having a problem trying to print some data of a table. I'm new at this php mysql stuff but i think my code is right. Here it is: <html> <body> <h1>Lista de usuários</h1> <?php $host="localhost"; // Host name $username="root"; // Mysql username $password=""; // Mysql password $db_name="sabs"; // Database name $tbl_name="doador"; // Table name // Connect to server and select database. mysql_connect("$host", "$username", "$password")or die("cannot connect"); mysql_select_db("$db_name")or die("cannot select DB"); $sql="SELECT * FROM $tbl_name"; $result=mysql_query($sql); while($rows = mysql_fetch_array($result)){ echo $row['id'] . " " .$row['nome'] . " " . $row['sobrenome'] . " " . $row['email'] . " " . $row['login'] . " " . $row['senha'] . " " . $row['idade'] . " ". $row['peso'] . " " . $row['fuma'] . " " . $row['sexo'] . " " . $row['doencas']; echo "<BR/>"; } mysql_close(); ?> </body> </html> All columns of the echo command exist in my table in the database. Don't get why it's not printing those values. Thanks for the attention.

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• How to output multiple rows from an SQL query using the mysqli object

  - by Jonathan

  Assuming that the mysqli object is already instantiatied (and connected) with the global variable $mysql, here is the code I am trying to work with. class Listing { private $mysql; function getListingInfo($l_id = "", $category = "", $subcategory = "", $username = "", $status = "active") { $condition = "`status` = '$status'"; if (!empty($l_id)) $condition .= "AND `L_ID` = '$l_id'"; if (!empty($category)) $condition .= "AND `category` = '$category'"; if (!empty($subcategory)) $condition .= "AND `subcategory` = '$subcategory'"; if (!empty($username)) $condition .= "AND `username` = '$username'"; $result = $this->mysql->query("SELECT * FROM listing WHERE $condition") or die('Error fetching values'); $this->listing = $result->fetch_array() or die('could not create object'); foreach ($this->listing as $key => $value) : $info[$key] = stripslashes(html_entity_decode($value)); endforeach; return $info; } } there are several hundred listings in the db and when I call $result-fetch_array() it places in an array the first row in the db. however when I try to call the object, I can't seem to access more than the first row. for instance: $listing_row = new Listing; while ($listing = $listing_row-getListingInfo()) { echo $listing[0]; } this outputs an infinite loop of the same row in the db. Why does it not advance to the next row? if I move the code: $this->listing = $result->fetch_array() or die('could not create object'); foreach ($this->listing as $key => $value) : $info[$key] = stripslashes(html_entity_decode($value)); endforeach; if I move this outside the class, it works exactly as expected outputting a row at a time while looping through the while statement. Is there a way to write this so that I can keep the fetch_array() call in the class and still loop through the records?

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• MYSQL variables - SET @var

  - by Lizard

  I am attempting to create a mysql snippet that will analyse a table and remove duplicate entries (duplicates are based on two fields not entire record) I have the following code that works when I hard code the variables in the queries, but when I take them out and put them as variables I get mysql errors, below is the script SET @tblname = 'mytable'; SET @fieldname = 'myfield'; SET @concat1 = 'checkfield1'; SET @concat2 = 'checkfield2'; ALTER TABLE @tblname ADD `tmpcheck` VARCHAR( 255 ) NOT NULL; UPDATE @tblname SET `tmpcheck` = CONCAT(@concat1,'-',@concat2); CREATE TEMPORARY TABLE `tmp_table` ( `tmpfield` VARCHAR( 100 ) NOT NULL ) ENGINE = MYISAM ; INSERT INTO `tmp_table` (`tmpfield`) SELECT @fieldname FROM @tblname GROUP BY `tmpcheck` HAVING ( COUNT(`tmpcheck`) > 1 ); DELETE FROM @tblname WHERE @fieldname IN (SELECT `tmpfield` FROM `tmp_table`); ALTER TABLE @tblname DROP `tmpcheck`; I am getting the following error: #1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '@tblname ADD `tmpcheck` VARCHAR( 255 ) NOT NULL' at line 1 Is this because I can't use a variable for a table name? What else could be wrong or how wopuld I get around this issue. Thanks in adavnce

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• UIDs for data objects in MySQL

  - by Callash

  Hi there, I am using C++ and MySQL. I have data objects I want to persist to the database. They need to have a unique ID for identification purposes. The question is, how to get this unique ID? Here is what I came up with: 1) Use the auto_increment feature of MySQL. But how to get the ID then? I am aware that MySQL offers this "SELECT LAST_INSERT_ID()" feature, but that would be a race condition, as two objects could be inserted quite fast after each other. Also, there is nothing else that makes the objects discernable. Two objects could be created pretty much at the same time with exactly the same data. 2) Generate the UID on the C++ side. No dice, either. There are multiple programs that will write to and read from the database, who do not know of each other. 3) Insert with MAX(uid)+1 as the uid value. But then, I basically have the same problem as in 1), because we still have the race condition. Now I am stumped. I am assuming that this problem must be something other people ran into as well, but so far, I did not find any answers. Any ideas?

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• URL Multiple Query Parameters Encoded with HTML Entities

  - by BRADINO

  I came across a situation where a URL with multiple query parameters was encoded using htmlentities() and PHP was not recognizing the query parameters using $_GET. A common case for encoding urls using htmlentities() is to use them inside XML documents. So a url with multiple query parameters, encoded using htmlentities() would look like this: http://www.bradino.com/?color=white&amp;size=medium&amp;quantity=3 and when that url is accessed the second and third query parameters are not recognized because instead of separating the subsequent variables with an & that character gets converted into &amp;. I could not find a good way to resolve this, so basically I just encoded the query string back to normal using html_entity_decode() and then slammed the parameters back into the $_GET array using parse_str(). $query = html_entity_decode($_SERVER['QUERY_STRING']); parse_str($query,$_GET); There must be a better way! Anyone come across this before?

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• Ordering by top commented.

  - by MILESMIBALERR

  How would I list a page of the top commented pages on the site with PHP and mysql. The database is set up sort of like this: page_id | username | comment | date_submitted page 1-------bob-------hello-----current date page 1-------joe-------byebye-----current date page 4-------joe--------stuff-------date page 3-------mark--------this--------a date how would you query it so that it orders them by top commented pages? here is a simple query to start with: $querycomments = sprintf("SELECT * FROM comments WHERE !!!!!HELLLLLP HERRE!!!!! = %s ORDER BY !!!!!!HELLLP HERE!!!!!! DESC", GetSQLValueString(????????????, "text"));

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• I need to calculate the date / time difference between one date time column

  - by Stringz

  Details. I have the notes table having the following columns. ID - INT(3) Date - DateTime Note - VARCHAR(100) Tile - Varchar(100) UserName - Varchar(100) Now this table will be having NOTES along with the Titles entered by UserName on the specified date / time. I need to calculate the DateTimeDifference between the TWO ROWS in the SAME COLUMN For example the above table has this peice of information in the table. 64, '2010-03-26 18:16:13', 'Action History', 'sending to Level 2.', 'Salman Khwaja' 65, '2010-03-26 18:19:48', 'Assigned By', 'This is note one for the assignment of RF.', 'Salman Khwaja' 66, '2010-03-27 19:19:48', 'Assigned By', 'This is note one for the assignment of CRF.', 'Salman Khwaja' Now I need to have the following resultset in query reports using MYSQL. TASK - TIME Taken ACTION History - 2010-03-26 18:16:13 Assigned By - 00:03:35 Assigned By - 25:00:00 More smarter approach would be TASK - TIME Taken ACTION History - 2010-03-26 18:16:13 Assigned By - 3 minutes 35 seconds Assigned By - 1 day, 1 hour. I would appreciate if one could give me the PLAIN QUERY along with PHP code to embed it too.

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• How would I UPDATE these table entries with SQL and PHP?

  - by CT

  I am working on an Asset Database problem. I enter assets into a database. Every object is an asset and has variables within the asset table. An object is also a type of asset. In this example the type is server. Here is the Query to retrieve all necessary data: SELECT asset.id ,asset.company ,asset.location ,asset.purchaseDate ,asset.purchaseOrder ,asset.value ,asset.type ,asset.notes ,server.manufacturer ,server.model ,server.serialNumber ,server.esc ,server.warranty ,server.user ,server.prevUser ,server.cpu ,server.memory ,server.hardDrive FROM asset LEFT JOIN server ON server.id = asset.id WHERE asset.id = '$id' I then assign all results into single php variables. How would I write a query/script to update an asset?

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• Fetch posts with attachments in a certain category?

  - by TiuTalk

  I need to retreive a list of posts that have (at least) one attachment that belongs to a category in WordPress. The relation between attachments and categories I made by myself using the WordPress default method. Here's the query that i'm running right now: SELECT p.* FROM `wp_posts` AS p # The post INNER JOIN `wp_posts` AS a # The attachment ON p.`ID` = a.`post_parent` AND a.`post_type` = 'attachment' INNER JOIN `wp_term_relationships` AS ra ON a.`ID` = ra.`object_id` AND ra.`term_taxonomy_id` IN (3) # The category ID list WHERE p.`post_type` = 'post' ORDER BY p.`post_date` DESC LIMIT 15 The problem here is that the query only use the first found attachment, and if it doesn't belongs to the category, the result isn't returned.

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• How would I UPDATE these table entries with SQL?

  - by CT

  I am working on an Asset Database problem. I enter assets into a database. Every object is an asset and has variables within the asset table. An object is also a type of asset. In this example the type is server. Here is the Query to retrieve all necessary data: SELECT asset.id ,asset.company ,asset.location ,asset.purchaseDate ,asset.purchaseOrder ,asset.value ,asset.type ,asset.notes ,server.manufacturer ,server.model ,server.serialNumber ,server.esc ,server.warranty ,server.user ,server.prevUser ,server.cpu ,server.memory ,server.hardDrive FROM asset LEFT JOIN server ON server.id = asset.id WHERE asset.id = '$id' How would I write a query to update an asset?

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• Understanding #DAX Query Plans for #powerpivot and #tabular

  - by Marco Russo (SQLBI)

  Alberto Ferrari wrote a very interesting white paper about DAX query plans. We published it on a page where we'll gather articles and tools about DAX query plans: http://www.sqlbi.com/topics/query-plans/I reviewed the paper and this is the result of many months of study - we know that we just scratched the surface of this topic, also because we still don't have enough information about internal behavior of many of the operators contained in a query plan. However, by reading the paper you will start reading a query plan and you will understand how it works the optimization found by Chris Webb one month ago to the events-in-progress scenario. The white paper also contains a more optimized query (10 time faster), even if the performance depends on data distribution and the best choice really depends on the data you have. Now you should be curious enough to read the paper until the end, because the more optimized query is the last example in the paper!

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• SQL SELECT across two tables

  - by Brett Spurrier

  Hi there, I am a little confused as to how to approach this SQL query. I have two takes (equal number of records), and I would like to return a column with which is the division between the two. In other words, here is my not-working-correctly query: SELECT( (SELECT v FROM Table1) / (SELECT DotProduct FROM Table2) ); How would I do this? All I want it a column where each row equals the same row in Table1 divided by the same row in Table2. The resulting table should have the same number of rows, but I am getting something with a lot more rows than the original two tables. I am at a complete loss. Any advice?

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• SQL to get friends AND friends of friends of a user

  - by Enrique

  My MySQL tables structure is like this. USER int id varchar username FRIEND_LIST int user_id int friend_id For each friend relationship I insert 2 records in FRIEND_LIST. If user 1 is friend of user 2 then the next rows are inserted into FRIEND_LIST 1,2 2,1 I want to get the friends and friends of friends of an specific user. The select should return columns a, b, c. a: user_id b: friend_id c: username (username of friend_id ) If 1 is friend of 2 and 3. 2 is friend of 3, 4 and 5 3 is friend of 5,6,7 Then the query to get 1's friends and friends of friends should return: 1 2 two 1 3 three 2 1 one 2 3 three 2 4 four 2 5 five 3 1 one 3 5 five 3 6 six 3 7 seven Can I get this rows with a single query?

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• PHP While Loops from Arrays

  - by Michael

  I have a table that contains members names and a field with multiple ID numbers. I want to create a query that returns results where any values in the ID fields overlap with any values in the array. For example: lastname: Smith firstname: John id: 101, 103 I have Array #1 with the values 101, 102, 103 I want the query to output all members who have the values 101 or 102 or 103 listed in their id field with multiple ids listed. Array ( [0] => 101 [1] => 102 [2] => 103 ) $sql="SELECT firstname, lastname, id FROM members WHERE id LIKE '%".$array_num_1."%'"; $result=mysql_query($sql); while ($rows=mysql_fetch_array($result)) { echo $rows['lastname'].', '.$rows['firstname'].'-'.$rows['id']; }

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