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  • Jquery Show Fields depending on Select Menu value but on page load

    - by Tim
    Hello, This question refers to the question http://stackoverflow.com/questions/835259/jquery-show-hide-fields-depening-on-select-value <select id="viewSelector"> <option value="0">-- Select a View --</option> <option value="view1">view1</option> <option value="view2">view2</option> <option value="view3">view3</option> </select> <div id="view1"> <!-- content --> </div> <div id="view2a"> <!-- content --> </div> <div id="view2b"> <!-- content --> </div> <div id="view3"> <!-- content --> </div> $(document).ready(function() { $.viewMap = { '0' : $([]), 'view1' : $('#view1'), 'view2' : $('#view2a, #view2b'), 'view3' : $('#view3') }; $('#viewSelector').change(function() { // hide all $.each($.viewMap, function() { this.hide(); }); // show current $.viewMap[$(this).val()].show(); }); }); When I select the 2nd item in the menu it shows the corresponding field. The exception to this is when the on page load the select menu already has the 2nd menu item selected, the field does not show. As you may be able to tell, I am new to jquery and could definetly use some help with adjusting this code so that the selected item's field is shown on page load. Thanks, Tim

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  • mysql select query problem

    - by Chocho
    i have a form that has a multiple select drop down. a user can select more than one options in the select. the name of the select is array[]; using php i implode(",",$array) in mysql db, it stores the field as a text in this format "places"= "new york, toronto, london" when i want to display these fields i explode the commas. i am trying to run a report to display the places. here is my select: "select * from mytable where db.places .. userSelectedPlaces" how can i check toronto in lists of "places" that user selected? note "places" in the db might be either just "toronto" or it might be comma separated lists of places like "ny, toronto, london, paris, etc".

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  • Preview result of update/insert query whithout comitting changes to database in MySQL?

    - by Camsoft
    I am writing a script to import CSV files into existing tables within my database. I decided to do the insert/update operations myself using PHP and INSERT/UPDATE statements, and not use MySQL's LOAD INFILE command, I have good reasons for this. What I would like to do is emulate the insert/update operations and display the results to the user, and then give them the option of confirming that this is OK, and then committing the changes to the database. I'm using InnoDB database engine with support for transactions. Not sure if this helps but was thinking down the line of insert/update, query data, display to user, then either commit or rollback transaction? Any advise would be appreciated.

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  • How to Check for record existence and do Insert in MYSQL ?

    - by karthik
    How to Check for record existence and do Insert or Update in MYSQL ? I have a script, which has set of Insert statements for multiple tables. Now when i try to execute the Insert statement, i want to do the following.. Check for the record existence and then do Insert or Update. If the Record is not exist do Insert. If the Record is already do not do anything. How to accomplish this ? Note : The script with Insert Statements are generated programmaticaly using SP

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  • problems selecting a mutliple select value from database in Rails

    - by Ramy
    From inside of a form_for in rails, I'm inserting multiple select values into the database, like this: <div class="new-partner-form"> <%= form_for [:admin, matching_profile.partner, matching_profile], :html => {:id => "edit_profile", :multipart => true} do |f| %> <%= f.submit "Submit", :class => "hidden" %> <div class="rounded-block quarter-wide radio-group"> <h4>Exclude customers from source:</h4> <%= f.select :source, User.select(:source).group(:source).order(:source).map {|u| [u.source,u.source]}, {:include_blank => false}, {:multiple => true} %> <%= f.error_message_on :source %> </div> I'm then trying to pull the value from the database like this: def does_not_contain_source(matching_profiles) Expression.select(matching_profiles, :source) do |keyword| Rails.logger.info("Keyword is : " + keyword) @customer_source_tokenizer ||= Tokenizer.new(User.select(:source).where("id = ?", self.owner_id).map {|u| u.source}[0]) #User.select("source").where("id = ?", self.owner_id).to_s) @customer_source_tokenizer.divergent?(keyword) end end but getting this: ExpressionErrors: Bad syntax: --- - "" - B - "" this is what the value is in the database but it seems to choke when i access it this way. What's the right way to do this?

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  • Access values of a group of select boxes in php from post

    - by 2Real
    Hi, I'm new to PHP, and I can't figure this out. I'm trying to figure out how to access the data of a group of select boxes I have defined in my HTML code. I tried grouping them as a class, but that doesn't seem to work... maybe I was doing it wrong. This is the following HTML code. <form action="" method="post"> <select class="foo"> <option> 1.....100</option> </select> <select class="foo"> <option> 1.... 500></option> </select> <input type="submit" value="Submit" name="submit"/> </form> I essentially want to group all my select boxes and access all the values in my PHP code. Thanks

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  • MySQL InnoDB Cascade Rule that looks at 2 columns?

    - by Travis
    I have the following MySQL InnoDB tables... TABLE foldersA ( ID title ) TABLE foldersB ( ID title ) TABLE records ( ID folderID folderType title ) folderID in table "records" can point to ID in either "foldersA" or "foldersB" depending on the value of folderType. (0 or 1). I am wondering: Is there a way to create a CASCADE rule such that the appropriate rows in table records are automatically deleted when a row in either foldersA or folderB is deleted? Or in this situation, am I forced to have to delete the rows in table "records" programatically? Thanks for you help!

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  • Preview result of update/insert query without comitting changes to database in MySQL?

    - by Camsoft
    I am writing a script to import CSV files into existing tables within my database. I decided to do the insert/update operations myself using PHP and INSERT/UPDATE statements, and not use MySQL's LOAD INFILE command, I have good reasons for this. What I would like to do is emulate the insert/update operations and display the results to the user, and then give them the option of confirming that this is OK, and then committing the changes to the database. I'm using InnoDB database engine with support for transactions. Not sure if this helps but was thinking down the line of insert/update, query data, display to user, then either commit or rollback transaction? Any advise would be appreciated.

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  • Can you reuse a mysql result set in PHP?

    - by MarathonStudios
    I have a result set I pull from a large database: $result = mysql_query($sql); I loop through this recordset once to pull specific bits of data and get averages using while($row = mysql_fetch_array($result)). Later in the page, I want to loop through this same recordset again and output everything - but because I used the recordset earlier, my second loop returns nothing. I finally hacked around this by looping through a second identical recordset ($result2 = mysql_query($sql);), but I hate to make the same SQL call twice. Any way I can loop through the same dataset multiple times?

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  • document.getElementById returns null for my drop-down select menu

    - by tucson
    I am trying to create a drop-down select menu with custom css (similar to the drop-down selection of language at http://translate.google.com/#). I have current html code: <ul id="Select"> <li> <select id="myId" onmouseover="mopen('options')" onmouseout="mclosetime()"> <div id="options" onmouseover="mcancelclosetime()" onmouseout="mclosetime()"> <option value="1" selected="selected">One</option> <option value="2">Two</option> <option value="3">Three</option> </div> </select> </li> </ul> and the Javascript: function mopen(id) { // cancel close timer mcancelclosetime(); // close old layer if(ddmenuitem) ddmenuitem.style.visibility = 'hidden'; // get new layer and show it ddmenuitem = document.getElementById(id); ddmenuitem.style.visibility = 'visible'; } But document.getElementById returns null. Though if I use the code with a div element that does not contain a select list the document.getElementById(id) returns proper div value. How do I fix this? or is there a better way to create drop-down select menu like http://translate.google.com ?

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  • MySQL, return only rows where there are duplicates among two columns.

    - by Richard Waite
    I have a table in MySQL of contact information ; first name, last name, address, etc. I would like to run a query on this table that will return only rows with first and last name combinations which appear in the table more than once. I do not want to group the "duplicates" (which may only be duplicates of the first and last name, but not other information like address or birthdate) - I want to return all the "duplicate" rows so I can look over the results and determine if they are dupes or not. This seemed like it would be a simple thing to do, but it has not been. Every solution I can find either groups the dupes and gives me a count only (which is not useful for what I need to do with the results) or doesn't work at all. Is this kind of logic even possible in a query ? Should I try and do this in Python or something?

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  • Move SELECT to SQL Server side

    - by noober
    Hello all, I have an SQLCLR trigger. It contains a large and messy SELECT inside, with parts like: (CASE WHEN EXISTS(SELECT * FROM INSERTED I WHERE I.ID = R.ID) THEN '1' ELSE '0' END) AS IsUpdated -- Is selected row just added? as well as JOINs etc. I like to have the result as a single table with all included. Question 1. Can I move this SELECT to SQL Server side? If yes, how to do this? Saying "move", I mean to create a stored procedure or something else that can be executed before reading dataset in while cycle. The 2 following questions make sense only if answer is "yes". Why do I want to move SELECT? First off, I don't like mixing SQL with C# code. At second, I suppose that server-side queries run faster, since the server have more chances to cache them. Question 2. Am I right? Is it some sort of optimizing? Also, the SELECT contains constant strings, but they are localizable. For instance, WHERE R.Status = "Enabled" "Enabled" should be changed for French, German etc. So, I want to write 2 static methods -- OnCreate and OnDestroy -- then mark them as stored procedures. When registering/unregistering my assembly on server side, just call them respectively. In OnCreate format the SELECT string, replacing {0}, {1}... with required values from the assembly resources. Then I can localize resources only, not every script. Question 3. Is it good idea? Is there an existing attribute to mark methods to be executed by SQL Server automatically after (un)registartion an assembly? Regards,

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  • How to UNION ALL two SELECT statements?

    - by Lisa
    I have 2 tables, one looks like this: TABLE ONE id | Last Name | First Name | Username | Password | Secret Question and another that looks like this: TABLE TWO id | Hobby | Country | I want to combine a Select statement that grabs data from both tables and output the results. The following code: $select = mysql_query(" SELECT * FROM table_one WHERE Username = 'Bob' UNION ALL SELECT * FROM table_two WHERE Hobby = 'Baseball' "); while ($return = mysql_fetch_assoc($select)) { $userName = $return['Username']; $hobby = $return['Hobby']; } echo "$userName likes $hobby"; results in a The used SELECT statements have a different number of columns error, what am I doing wrong?

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  • Multiple connections to a MySQL database in a single PHP script.

    - by st3
    There are multiple times in one page where I need to connect and subsequently query a MySQL database, yet my code won't let me. I think it might be something to do with how my files are nested but it makes no sense. I am opening the SQL connection in the header file. The top of the offending page looks like the following: <?php $page_title = 'Dashboard'; include('templates/header.inc'); // includes a 'require_once('mysqli_connect.php') and a small query to the database; require_once('includes/functions.php'); require_once('includes/dashboard_sql.php'); // Contains functions which connect to database (which are failing.) ?> I get the PHP error Notice: Undefined variable: dbc in /Library/WebServer/Documents/pediatory_site/includes/dashboard_sql.php Where $dbc is the database connection defined in mysqli_connect.php. If anyone could help me out that would be great.

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  • html/js: Refresh 'Select' options

    - by framara
    Hi, There's a class 'Car' with brand and model as properties. I have a list of items of this class List<Car> myCars. I need to represent in a JSP website 2 ComboBox, one for brand and another for model, that when you select the brand, in the model list only appear the ones from that brand. I don't know how to do this in a dynamic way. Any suggestion where to start? Thanks Update Ok, what I do now is send in the request a list with all the brand names, and a list of the items. The JSP code is like: <select name="manufacturer" id="id_manufacturer" onchange="return getManufacturer();"> <option value=""></option> <c:forEach items="${manufacturers}" var="man"> <option value="${man}" >${man}</option> </c:forEach> </select> <select name="model" id="id_model"> <c:forEach items="${mycars}" var="car"> <c:if test="${car.manufacturer eq man_selected}"> <option value="${car.id}">${car.model}</option> </c:if> </c:forEach> </select> <script> function getManufacturer() { man_selected = document.getElementById('id_manufacturer').value; } </script> How do I do to refresh the 'model' select options according to the selected 'man_selected' ?

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  • MySQL - Counting rows in preparation for greatest-n-per-group not working?

    - by John M
    Referring to SO and other sites have given me examples of how to use MySQL to create a 'greatest-n-per-group' query. My variant on this would be to have a query that returns the first 3 rows of each category. As the basis for this I need to sort my data into a usable sequence and that is where my problems start. Running just the sequence query with row numbering shows that changes in category are mostly ignored. I should have 35 categories returning rows but only 5 do so. My query: set @c:=0; set @a:=0; SELECT IF(@c = tdg, @a:=@a+1, @a:=1) AS rownum, (@c:=tdg) , julian_day, sequence, complete, year, tdg FROM tsd WHERE complete = 0 order by tdg, year, julian_day, sequence Do I have a syntax mistake with this query?

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  • Can't use MySQL extract() function in the WHERE clause.

    - by UkraineTrain
    I've run the following query: UPDATE main_table, reference_table SET main_table.calc_column = (CASE WHEN main_table.incr = "6AM" THEN reference_table.col1+reference_table.col2+... WHEN main_table.incr = "12AM" THEN reference_table.col7+reference_table.col8+... WHEN main_table.incr = "6PM" THEN reference_table.col13+reference_table.col14+... ELSE reference_table.col19+reference_table.col20+...) WHERE main_table.month = extract(month from reference_table.thedate) AND main_table.day = extract(day from reference_table.thedate) I've used extract() function since my reference_table doesn't have month and day columns but has the date column named thedate. I've used the extract() function on the reference_table many times before successfully, so, I know that there's nothing wrong with my extract function syntax. However, in this instance, MySQL complains. It probably has to do with the fact that I've used in the WHERE clause. I know that this issue could get fixed if I added the month and day columns to the reference_table to avoid using the extract() function. However, I'm very reluctant to do that and would like to avoid it. How can I make it work?`

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  • Jquery - Setting form select-field "selected" value only works after refresh

    - by frequent
    Hi, I want to use a form select-field for users to select their country of residence, which shows the IP based country as default value (plus the IP address next to it); Location info (ipinfodb.com) is working. I'm passing "country" and "ip" to the function, which should modify select-field and ip adress Problem: IP adress works, but the select-field only updates after I hit refresh. Can someone tell me why? Here is the code: HTML <select name="setup_changeCountry" id="setup_changeCountry"> <option value="AL-Albania">Albanien</option> <option value="AD-Andorra">Andorra</option> <option value="AM-Armenia">Armenien</option> <option value="AU-Australia">Australien</option> ... </select> <div class="setup_IPInfo"> <span>Your IP</span> <span class="ipAdress"> -- ip --</span> </div> Javascript/Jquery function morph(country,ip) >> passed from function, called on DOMContentLoaded { var ipAdress = ip; $('.ipAdress').text(ipAdress); var countryForm = country; $('#setup_changeCountry option').each(function() { if ($(this).val().substr(0,2) == countryForm) { $(this).attr('selected', "true"); } }); } Thanks for any clues on how to fix this. Frequent

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  • Installing Rails, MySQL, etc. everything goes wrong

    - by Rits
    I've been struggling with this for a few hours. Everything just stopped working and I can't get it to work anymore. I'm a noob at Ruby, Ruby on Rails and the Terminal in general. This is really frustrating me so I just try to describe my problem as detailed as possible hoping someone can give me a solution. I'm on Mac OS X Snow Leopard. I couldn't get Rails working at all just now: Could not find gem 'rails' headaches But after some tries of reinstalling it, it suddenly worked again. But now I just can't get MySQL to work, and it sometimes even breaks the Rails installation again. This is what I do: sudo gem uninstall rails sudo gem uninstall mysql sudo gem uninstall mysql2 After these commands, I check the installed gems with gem list. No MySQL gem is listed anymore, but I can still see rails (2.3.5, 2.2.2, 1.2.6) . Is this normal? Does this mean I have 3 Rails installations? It doesn't make sense to me. Anyway, then I do this: sudo gem clean Which fails completely. I get a bunch of errors like this: Attempting to uninstall fcgi-0.8.7 Unable to uninstall fcgi-0.8.7: Gem::InstallError: cannot uninstall, check gem list -d fcgi It doesn't uninstall anything. At this point, I try to install everything again. I start with: sudo gem install rails Which succeeds (I think): Successfully installed rails-3.0.3 Successfully installed builder-2.1.2 2 gems installed Installing ri documentation for rails-3.0.3... File not found: lib Then, I update RubyGems: sudo gem update --system sudo gem install rubygems-update sudo update_rubygems Then it says I have 1.3.7 installed, so it succeeded, I think. So now I proceed with installing MySQL. I already got MySQL 5.5.8 installed on my machine. I did some research about installing MySQL on Snow Leopard, and it seems I have to use this command: sudo env ARCHFLAGS="-arch x86_64" gem install mysql -- --with-mysql-config=/usr/local/mysql/bin/mysql_config I get a bunch of errors like this: No definition for time_set_neg No definition for time_set_second_part No definition for time_equal No definition for error_errno At this point, I assume I got both Rails and the MySQL gem installed, so I try to start a new project. rails new user_group -d mysql It works! Rails is installed correctly. Now, I try generating a model. cd user_group rails generate model User It fails with this error: Could not find gem 'mysql2 (= 0, runtime)' in any of the gem sources listed in your Gemfile. Try running bundle install. So I try running bundle install. It installs a lot of gems. Then I try to generate my model again. I get this error: Library/Ruby/Gems/1.8/gems/mysql2-0.2.6/lib/mysql2/mysql2.bundle: dlopen(/Library/Ruby/Gems/1.8/gems/mysql2-0.2.6/lib/mysql2/mysql2.bundle, 9): Library not loaded: libmysqlclient.16.dylib (LoadError) Referenced from: /Library/Ruby/Gems/1.8/gems/mysql2-0.2.6/lib/mysql2/mysql2.bundle Reason: image not found - /Library/Ruby/Gems/1.8/gems/mysql2-0.2.6/lib/mysql2/mysql2.bundle This is as far as I can get. What should I do? And why should this be so hard...

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  • NHibernate MySQL Composite-Key

    - by LnDCobra
    I am trying to create a composite key that mimicks the set of PrimaryKeys in the built in MySQL.DB table. The Db primary key is as follows: Field | Type | Null | ---------------------------------- Host | char(60) | No | Db | char(64) | No | User | char(16) | No | This is my DataBasePrivilege.hbm.xml file <?xml version="1.0" encoding="utf-8" ?> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="TGS.MySQL.DataBaseObjects" namespace="TGS.MySQL.DataBaseObjects"> <class name="TGS.MySQL.DataBaseObjects.DataBasePrivilege,TGS.MySQL.DataBaseObjects" table="db"> <composite-id name="CompositeKey" class="TGS.MySQL.DataBaseObjects.DataBasePrivilegePrimaryKey, TGS.MySQL.DataBaseObjects"> <key-property name="Host" column="Host" type="char" length="60" /> <key-property name="DataBase" column="Db" type="char" length="64" /> <key-property name="User" column="User" type="char" length="16" /> </composite-id> </class> </hibernate-mapping> The following are my 2 classes for my composite key: namespace TGS.MySQL.DataBaseObjects { public class DataBasePrivilege { public virtual DataBasePrivilegePrimaryKey CompositeKey { get; set; } } public class DataBasePrivilegePrimaryKey { public string Host { get; set; } public string DataBase { get; set; } public string User { get; set; } public override bool Equals(object obj) { if (ReferenceEquals(null, obj)) return false; if (ReferenceEquals(this, obj)) return true; if (obj.GetType() != typeof (DataBasePrivilegePrimaryKey)) return false; return Equals((DataBasePrivilegePrimaryKey) obj); } public bool Equals(DataBasePrivilegePrimaryKey other) { if (ReferenceEquals(null, other)) return false; if (ReferenceEquals(this, other)) return true; return Equals(other.Host, Host) && Equals(other.DataBase, DataBase) && Equals(other.User, User); } public override int GetHashCode() { unchecked { int result = (Host != null ? Host.GetHashCode() : 0); result = (result*397) ^ (DataBase != null ? DataBase.GetHashCode() : 0); result = (result*397) ^ (User != null ? User.GetHashCode() : 0); return result; } } } } And the following is the exception I am getting: Execute System.InvalidCastException: Unable to cast object of type 'System.Object[]' to type 'TGS.MySQL.DataBaseObjects.DataBasePrivilegePrimaryKey'. at (Object , GetterCallback ) at NHibernate.Bytecode.Lightweight.AccessOptimizer.GetPropertyValues(Object target) at NHibernate.Tuple.Component.PocoComponentTuplizer.GetPropertyValues(Object component) at NHibernate.Type.ComponentType.GetPropertyValues(Object component, EntityMode entityMode) at NHibernate.Type.ComponentType.GetHashCode(Object x, EntityMode entityMode) at NHibernate.Type.ComponentType.GetHashCode(Object x, EntityMode entityMode, ISessionFactoryImplementor factory) at NHibernate.Engine.EntityKey.GenerateHashCode() at NHibernate.Engine.EntityKey..ctor(Object identifier, String rootEntityName, String entityName, IType identifierType, Boolean batchLoadable, ISessionFactoryImplementor factory, EntityMode entityMode) at NHibernate.Engine.EntityKey..ctor(Object id, IEntityPersister persister, EntityMode entityMode) at NHibernate.Event.Default.DefaultLoadEventListener.OnLoad(LoadEvent event, LoadType loadType) at NHibernate.Impl.SessionImpl.FireLoad(LoadEvent event, LoadType loadType) at NHibernate.Impl.SessionImpl.Get(String entityName, Object id) at NHibernate.Impl.SessionImpl.Get(Type entityClass, Object id) at NHibernate.Impl.SessionImpl.Get[T](Object id) at TGS.MySQL.DataBase.DataProvider.GetDatabasePrivilegeByHostDbUser(String host, String db, String user) in C:\Documents and Settings\Michal\My Documents\Visual Studio 2008\Projects\TGS\TGS.MySQL.DataBase\DataProvider.cs:line 20 at TGS.UserAccountControl.UserAccountManager.GetDatabasePrivilegeByHostDbUser(String host, String db, String user) in C:\Documents and Settings\Michal\My Documents\Visual Studio 2008\Projects\TGS\TGS.UserAccountControl\UserAccountManager.cs:line 10 at TGS.UserAccountControlTest.UserAccountManagerTest.CanGetDataBasePrivilegeByHostDbUser() in C:\Documents and Settings\Michal\My Documents\Visual Studio 2008\Projects\TGS\TGS.UserAccountControlTest\UserAccountManagerTest.cs:line 12 I am new to NHibernate and any help would be appreciated. I just can't see where it is getting the object[] from? Is the composite key supposed to be object[]?

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  • SQL queries break our game! (Back-end server is at capacity)

    - by TimH
    We have a Facebook game that stores all persistent data in a MySQL database that is running on a large Amazon RDS instance. One of our tables is 2GB in size. If I run any queries on that table that take more than a couple of seconds, any SQL actions performed by our game will fail with the error: HTTP/1.1 503 Service Unavailable: Back-end server is at capacity This obviously brings down our game! I've monitored CPU usage on the RDS instance during these periods, and though it does spike, it doesn't go much over 50%. Previously we were on a smaller instance size and it did hit 100%, so I'd hoped just throwing more CPU capacity at the problem would solve it. I now think it's an issue with the number of open connections. However, I've only been working with SQL for 8 months or so, so I'm no expert on MySQL configuration. Is there perhaps some configuration setting I can change to prevent these queries from overloading the server, or should I just not be running them whilst our game is up? I'm using MySQL Workbench to run the queries. Here's an example.... SELECT * FROM BlueBoxEngineDB.Transfer WHERE Amount = 1000 AND FromUserId = 4 AND Status='Complete'; As you can see, it's not overly complex. There are only 5 columns in the table. Any help would be very much appreciated - Thanks!

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  • Why isn't my query using any indices when I use a subquery?

    - by sfussenegger
    I have the following tables (removed columns that aren't used for my examples): CREATE TABLE `person` ( `id` int(11) NOT NULL, `name` varchar(1024) NOT NULL, `sortname` varchar(1024) NOT NULL, PRIMARY KEY (`id`), KEY `sortname` (`sortname`(255)), KEY `name` (`name`(255)) ); CREATE TABLE `personalias` ( `id` int(11) NOT NULL, `person` int(11) NOT NULL, `name` varchar(1024) NOT NULL, PRIMARY KEY (`id`), KEY `person` (`person`), KEY `name` (`name`(255)) ) Currently, I'm using this query which works just fine: select p.* from person p where name = 'John Mayer' or sortname = 'John Mayer'; mysql> explain select p.* from person p where name = 'John Mayer' or sortname = 'John Mayer'; +----+-------------+-------+-------------+---------------+---------------+---------+------+------+----------------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+-------------+---------------+---------------+---------+------+------+----------------------------------------------+ | 1 | SIMPLE | p | index_merge | name,sortname | name,sortname | 767,767 | NULL | 3 | Using sort_union(name,sortname); Using where | +----+-------------+-------+-------------+---------------+---------------+---------+------+------+----------------------------------------------+ 1 row in set (0.00 sec) Now I'd like to extend this query to also consider aliases. First, I've tried using a join: select p.* from person p join personalias a where p.name = 'John Mayer' or p.sortname = 'John Mayer' or a.name = 'John Mayer'; mysql> explain select p.* from person p join personalias a on p.id = a.person where p.name = 'John Mayer' or p.sortname = 'John Mayer' or a.name = 'John Mayer'; +----+-------------+-------+--------+-----------------------+---------+---------+-------------------+-------+-----------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+--------+-----------------------+---------+---------+-------------------+-------+-----------------+ | 1 | SIMPLE | a | ALL | ref,name | NULL | NULL | NULL | 87401 | Using temporary | | 1 | SIMPLE | p | eq_ref | PRIMARY,name,sortname | PRIMARY | 4 | musicbrainz.a.ref | 1 | Using where | +----+-------------+-------+--------+-----------------------+---------+---------+-------------------+-------+-----------------+ 2 rows in set (0.00 sec) This looks bad: no index, 87401 rows, using temporary. Using temporary only appears when I use distinct, but as an alias might be the same as the name, I can't really get rid of it. Next, I've tried to replace the join with a subquery: select p.* from person p where p.name = 'John Mayer' or p.sortname = 'John Mayer' or p.id in (select person from personalias a where a.name = 'John Mayer'); mysql> explain select p.* from person p where p.name = 'John Mayer' or p.sortname = 'John Mayer' or p.id in (select id from personalias a where a.name = 'John Mayer'); +----+--------------------+-------+----------------+------------------+--------+---------+------+--------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+--------------------+-------+----------------+------------------+--------+---------+------+--------+-------------+ | 1 | PRIMARY | p | ALL | name,sortname | NULL | NULL | NULL | 540309 | Using where | | 2 | DEPENDENT SUBQUERY | a | index_subquery | person,name | person | 4 | func | 1 | Using where | +----+--------------------+-------+----------------+------------------+--------+---------+------+--------+-------------+ 2 rows in set (0.00 sec) Again, this looks pretty bad: no index, 540309 rows. Interestingly, both queries (select p.* from person ... or p.id in (4711,12345) and select id from personalias a where a.name = 'John Mayer') work extremely well. Why doesn't MySQL use any indices for both of my queries? What else could I do? Currently, it looks best to fetch person.ids for aliases and add them statically as an in(...) to the second query. There certainly has to be another way to do this with a single query. I'm currently out of ideas though. Could I somehow force MySQL into using another (better) query plan?

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  • SQL SERVER – Tricks to Replace SELECT * with Column Names – SQL in Sixty Seconds #017 – Video

    - by pinaldave
    You might have heard many times that one should not use SELECT * as there are many disadvantages to the usage of the SELECT *. I also believe that there are always rare occasion when we need every single column of the query. In most of the cases, we only need a few columns of the query and we should retrieve only those columns. SELECT * has many disadvantages. Let me list a few and remaining you can add as a comment.  Retrieves unnecessary columns and increases network traffic When a new columns are added views needs to be refreshed manually Leads to usage of sub-optimal execution plan Uses clustered index in most of the cases instead of using optimal index It is difficult to debug. There are two quick tricks I have discussed in the video which explains how users can avoid using SELECT * but instead list the column names. 1) Drag the columns folder from SQL Server Management Studio to Query Editor 2) Right Click on Table Name >> Script TAble AS >> SELECT To… >> Select option It is extremely easy to list the column names in the table. In today’s sixty seconds video, you will notice that I was able to demonstrate both the methods very quickly. From now onwards there should be no excuse for not listing ColumnName. Let me ask a question back – is there ever a reason to SELECT *? If yes, would you please share that as a comment. More on SELECT *: SQL SERVER – Solution – Puzzle – SELECT * vs SELECT COUNT(*) SQL SERVER – Puzzle – SELECT * vs SELECT COUNT(*) SQL SERVER – SELECT vs. SET Performance Comparison I encourage you to submit your ideas for SQL in Sixty Seconds. We will try to accommodate as many as we can. If we like your idea we promise to share with you educational material. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Database, Pinal Dave, PostADay, SQL, SQL Authority, SQL in Sixty Seconds, SQL Query, SQL Scripts, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology, Video

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  • Using Teleriks new LINQ implementation to connect to MySQL

    Last week Telerik released a new LINQ implementation that is simple to use and produces domain models very fast. Built on top of the enterprise grade OpenAccess ORM, you can connect to any database that OpenAccess can connect to such as: SQL Server, MySQL, Oracle, SQL Azure, VistaDB, etc. Today I will show you how to build a domain model using MySQL as your back end. To get started, you have to download MySQL 5.x and the MySQL Workbench and also, as my colleague Alexander Filipov at Telerik reminded me, make sure you install the MySQL .NET Connector, which is available here.  I like to use Northwind, ok it gives me the warm and fuzzies, so I ran a script to produce Northwind on my MySQL server. There are many ways you can get Northwind on your MySQL database, here is a helpful blog to get your started. I also manipulated the first record to indicate that I am in MySQL and gave a look via the MySQL Workbench. Ok, time to build our model! Start up the Domain Model wizard by right clicking on the project in Visual Studio (I have a Web project) and select Add|New Item and choose Telerik OpenAccess Domain Model from the new item list. When the wizard comes up, choose MySQL as your back end and enter in the name of your saved MySQL connection. If you dont have a saved MySQL connection set up in Visual Studio, click on New Connection and enter in the proper connection information. *Note, this is where you need to have the MySQL .NET connector installed. After you set your connection to the MySQL database server, you have to choose which tables to include in your model. Just for fun, I will choose all of them. Give your model a name, like NorthwindEntities and click finish. That is it. Now lets consume the model with ASP .net. I created a simple page that also has a GridView on it. On my page load I wrote this code, by now it should look very familiar, a simple LINQ query filtering customers by country (Germany) and binding the results to the grid.  1: protected void Page_Load(object sender, EventArgs e) 2: { 3: if (!IsPostBack) 4: { 5: //a reference to the data context 6: NorthwindEntities dat = new NorthwindEntities(); 7: //LINQ Statement 8: var result = from c in dat.Customers 9: where c.Country == "Germany" 10: select c; 11: //Databinding to the Gridview 12: GridView1.DataSource = result; 13: GridView1.DataBind(); 14: } 15: } .csharpcode, .csharpcode pre{ font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/}.csharpcode pre { margin: 0em; }.csharpcode .rem { color: #008000; }.csharpcode .kwrd { color: #0000ff; }.csharpcode .str { color: #006080; }.csharpcode .op { color: #0000c0; }.csharpcode .preproc { color: #cc6633; }.csharpcode .asp { background-color: #ffff00; }.csharpcode .html { color: #800000; }.csharpcode .attr { color: #ff0000; }.csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em;}.csharpcode .lnum { color: #606060; } F5 produces the following. Tomorrow Ill show how to take the same model and create an Astoria/OData data feed. Technorati Tags: MySQL Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • MySQL error: Can't find symbol '_mysql_plugin_interface_version_' in library

    - by Josh Smith
    The boring, necessary details: I'm on Snow Leopard running MySQL locally. I'm trying to install the Sphinx engine for MySQL like so: mysql> install plugin sphinx soname 'sphinx.so'; ERROR 1127 (HY000): Can't find symbol '_mysql_plugin_interface_version_' in library I've Googled everywhere and can't seem to find an actual solution to this problem. For example this issue on the Sphinx forums seems unresolved. Someone else also raised this issue with similar results. The first post linked to an O'Reilly article which says: There is a common problem that might occur at this point: ERROR 1127 (HY000): Can't find symbol '_mysql_plugin_interface_version_' in library If you see a message like this, it is likely that you forgot to include the -DMYSQL_DYNAMIC_PLUGIN option when compiling the plugin. Adding this option to the g++ compile line is required to create a dynamically loadable plug-in. But the article ends on that point; I have no idea what this means or how to resolve the issue.

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