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  • How to configure database connection securely

    - by chiccodoro
    Similar but not the same: How to securely store database connection details Securely connecting to database within a application Hi all, I have a C# WinForms application connecting to a database server. The database connection string, including a generic user/pass, is placed in a NHibernate configuration file, which lies in the same directory as the exe file. Now I have this issue: The user that runs the application should not get to know the username/password of the general database user because I don't want him to rummage around in the database directly. Alternatively I could hardcode the connection string, which is bad because the administrator must be able to change it if the database is moved or if he wants to switch between dev/test/prod environments. So long I've found three possibilities: The first referenced question was generally answered by making the file only readable for the user that runs the application. But that's not not enough in my case (the user running the application is a person. The database user/pass are general and shouldn't even be accessible by the person.) The first answer additionally proposed to encrypt the connection data before writing it to the file. With this approach, the administrator is not able anymore to configure the connection string because he cannot encrypt it by hand. The second referenced question provides an approach for this very scenario but it seems very complicated. My questions to you: This is a very general issue, so isn't there any general "how-to-do-it" way, somehow a "design pattern"? Is there some support in .NET's config infrastructure? (optional, maybe out of scope) Can I combine that easily with the NHibernate configuration mechanism?

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  • Database for Python Twisted

    - by Will
    There's an API for Twisted apps to talk to a database in a scalable way: twisted.enterprise.dbapi The confusing thing is, which database to pick? The database will have a Twisted app that is mostly making inserts and updates and relatively few selects, and then other strictly-read-only clients that are accessing the database directly making selects. (The read-only users are not necessarily selecting the data that the Twisted app is inserting; its not as though the database is being used as a message-queue) My understanding - which I'd like corrected/adviced - is that: Postgres is a great DB, but all the Python bindings - and there is a confusing maze of them - are abandonware There is psycopg2, but that makes a lot of noise about doing its own connection-pooling and things; does this co-exist gracefully/usefully/transparently with the Twisted async database connection pooling and such? SQLLite is a great database for little things but if used in a multi-user way it does whole-database locking, so performance would suck in the usage pattern I envisage MySQL - after the Oracle takeover, who'd want to adopt it now or adopt a fork? Is there anything else out there?

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  • SQL Server Database In Single User Mode after Failover

    - by jlichauc
    Here is a weird situation we experienced with a SQL Server 2008 Database Mirroring Failover. We have a pair of mirrored databases running in high-availability mode and both the principal and mirror showed as synchronized. As part of some maintenance I triggered a manual failover of the principal to the mirror. However after the failover the principal was now in single-user mode instead of the expected "Principal/Synchronized" state we usually get. The database had been in multi-user mode on the previous principal before this had happened. We ended up stopping all applications, restarting the SQL Server instances, and executing "ALTER DATABASE ... SET MULTI_USER" to bring the database back to the expected "Principal/Synchronized" state in a multi-user mode. Question. Does anyone know where SQL Server stores information about whether a database should be in single-user mode or not? I'm wondering if there is some system database or table that has this setting recorded somewhere. In particular we had an incident once with the database on the original principal (the one I was failing over to) where when trying to detach the database it was put into single-user mode. I'm wondering if that setting is cached somewhere and is the reason that SQL Server put it back into single-user mode after a failover.

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  • how do i implement / build / create an 'in memory database' for my unit test

    - by Michel
    Hi all, i've started unit testing a while ago and as turned out i did more regression testing than unit testing because i also included my database layer thus going to the database verytime. So, implemented Unity to inject a fake database layer, but i of course want to store some data, and the main opinion was: "create an in-memory database" But what is that / how do i implement that? Main question is: i think i have to fake the database layer, but doesn't that make me create a 'simple database' myself or: how can i keep it simple and not rebuilding Sql Server just for my unit tests :) At the end of this question i'll give an explanation of the situation i got in on the project i just started on, and i was wondering if this was the way to go. Michel Current situation i've seen at this client is that testdata is contained in XML files, and there is a 'fake' database layer that connects all the xml files together. For the real database we're using the entity framework, and this works very simple. And now, in the 'fake' layer, i have top create all kind of classes to load, save, persist etc. the data. It sounds weird that there is so much work in the fake layer, and so little in the real layer. I hope this all makes sense :)

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  • How to optimize paging for large in memory database

    - by snakefoot
    I have an application where the entire database is implemented in memory using a stl-map for each table in the database. Each item in the stl-map is a complex object with references to other items in the other stl-maps. The application works with a large amount of data, so it uses more than 500 MByte RAM. Clients are able to contact the application and get a filtered version of the entire database. This is done by running through the entire database, and finding items relevant for the client. When the application have been running for an hour or so, then Windows 2003 SP2 starts to page out parts of the RAM for the application (Eventhough there is 16 GByte RAM on the machine). After the application have been partly paged out then a client logon takes a long time (10 mins) because it now generates a page fault for each pointer lookup in the stl-map. I can see it is possible to tell Windows to lock memory in RAM, but this is generally only recommended for device drivers, and only for "small" amounts of memory. I guess a poor mans solution could be to loop through the entire memory database, and thus tell Windows we are still interested in keeping the datamodel in RAM. I guess another poor mans solution could be to disable the pagefile completely on Windows. I guess the expensive solution would be a SQL database, and then rewrite the entire application to use a database layer. Then hopefully the database system will have implemented means to for fast access. Are there other more elegant solutions ?

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  • Partner Webcast – More out of ODA with DB Options - 19 July 2012

    - by Thanos
    The Simple, Reliable, Affordable Path to High-Availability Databases Critical business data needs to be available 24/7 for users and customers, but it can be a struggle to find the time and resources to build a highly available database system that’s reliable and affordable. That’s why Oracle created the new Oracle Database Appliance—a complete package of software, server, storage, and networking. The Oracle Database Appliance integrates the world’s most popular database - Oracle Database 11g  - with system software, servers, storage and networking in a single box. Business gets the benefit of a reliable, secure and highly available database to support applications and maintain continuity – as well as groundbreaking ease of use. But that is not all, with the support for all Oracle Database Options, Oracle Database Appliance can be the ideal solution for many use cases. The benefits?   Unmatched performance, reliability & security for your data that’s there when you need it – which is all the time. Fast installation, simple deployment, easy management. Out of the box. Significant cost savings & reduced risk and complexity compared to integrating all the elements yourself. Ongoing lower total cost of ownership with multiple automated support, detection & correction functions that also save you time.   Discover the Oracle Database Appliance Value Proposition and learn how to position and combine it with database options to capture new business and easily roll out solutions safely and with maximum cost efficiency. Agenda: Oracle Database& Engineered Systems Innovation. What’s the Oracle Database Appliance ? Oracle Database Appliance Value Proposition. Oracle Database Appliance with Database Options Oracle Database Appliance Partners Business Delivery Format This FREE online LIVE eSeminar will be delivered over the Web. Registrations received less than 24hours prior to start time may not receive confirmation to attend. Duration: 1 hour Register Now! For any questions please contact us at partner.imc-AT-beehiveonline.oracle-DOT-com Visit regularly our ISV Migration Center blog Or Follow us @oracleimc to learn more on Oracle Technologies as well as upcoming partner webcasts and events.

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  • Is it possible to write a database view that encompasses one-to-many relationships?

    - by Brandon Linton
    So I'm not necessarily saying this is even a good idea if it were possible, since the schema of the view would be extremely volatile, but is there any way to represent a has-many relationship in a single view? For example, let's say I have a customer that can have any number of addresses in the database. Is there any way to list out each column of each address with perhaps a number as a part of the alias (e.g., columns like Customer Id, Name, Address_Street_1, Address_Street_2, etc)? Thanks!

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  • SQL SERVER – Attach mdf file without ldf file in Database

    - by pinaldave
    Background Story: One of my friends recently called up and asked me if I had spare time to look at his database and give him a performance tuning advice. Because I had some free time to help him out, I said yes. I asked him to send me the details of his database structure and sample data. He said that since his database is in a very early stage and is small as of the moment, so he told me that he would like me to have a complete database. My response to him was “Sure! In that case, take a backup of the database and send it to me. I will restore it into my computer and play with it.” He did send me his database; however, his method made me write this quick note here. Instead of taking a full backup of the database and sending it to me, he sent me only the .mdf (primary database file). In fact, I asked for a complete backup (I wanted to review file groups, files, as well as few other details).  Upon calling my friend,  I found that he was not available. Now,  he left me with only a .mdf file. As I had some extra time, I decided to checkout his database structure and get back to him regarding the full backup, whenever I can get in touch with him again. Technical Talk: If the database is shutdown gracefully and there was no abrupt shutdown (power outrages, pulling plugs to machines, machine crashes or any other reasons), it is possible (there’s no guarantee) to attach .mdf file only to the server. Please note that there can be many more reasons for a database that is not getting attached or restored. In my case, the database had a clean shutdown and there were no complex issues. I was able to recreate a transaction log file and attached the received .mdf file. There are multiple ways of doing this. I am listing all of them here. Before using any of them, please consult the Domain Expert in your company or industry. Also, never attempt this on live/production server without the presence of a Disaster Recovery expert. USE [master] GO -- Method 1: I use this method EXEC sp_attach_single_file_db @dbname='TestDb', @physname=N'C:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA\TestDb.mdf' GO -- Method 2: CREATE DATABASE TestDb ON (FILENAME = N'C:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA\TestDb.mdf') FOR ATTACH_REBUILD_LOG GO Method 2: If one or more log files are missing, they are recreated again. There is one more method which I am demonstrating here but I have not used myself before. According to Book Online, it will work only if there is one log file that is missing. If there are more than one log files involved, all of them are required to undergo the same procedure. -- Method 3: CREATE DATABASE TestDb ON ( FILENAME = N'C:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA\TestDb.mdf') FOR ATTACH GO Please read the Book Online in depth and consult DR experts before working on the production server. In my case, the above syntax just worked fine as the database was clean when it was detached. Feel free to write your opinions and experiences for it will help the IT community to learn more from your suggestions and skills. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, Readers Question, SQL, SQL Authority, SQL Backup and Restore, SQL Data Storage, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Java: static-non-static-this problem

    - by HH
    $ javac TestFilter.java TestFilter.java:19: non-static variable this cannot be referenced from a static context for(File f : file.listFiles(this.filterFiles)){ ^ 1 error $ sed -i 's@this@TestFilter@g' TestFilter.java $ javac TestFilter.java $ java TestFilter file1 file2 file3 TestFilter.java import java.io.*; import java.util.*; public class TestFilter { private static final FileFilter filterFiles; // STATIC! static{ filterFiles = new FileFilter() { // Not Static below. When static, an error: // "accept(java.io.File) in cannot implement // accept(java.io.File) in java.io.FileFilter; // overriding method is static" // // I tried to solve by the change the problem at the bottom. public boolean accept(File file) { return file.isFile(); } }; } // STATIC! public static void main(String[] args){ HashSet<File> files = new HashSet<File>(); File file = new File("."); // IT DID NOT WORK WITH "This" but with "TestFilter". // Why do I get the error with "This" but not with "TestFilter"? for(File f : file.listFiles(TestFilter.filterFiles)){ System.out.println(f.getName()); files.add(f); } } }

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  • How to non-greedy multiple lookbehind matches

    - by ArtK
    Source: <prefix><content1><suffix1><prefix><content2><suffix2> Engine: PCRE RegEx1: (?<=<prefix>)(.*)(?=<suffix1>) RegEx2: (?<=<prefix>)(.*)(?=<suffix2>) Result1: <content1> Result2: <content1><suffix1><prefix><content2> The desired result for RegEx2 is just <content2> but it is obviously greedy. How do I make RegEx2 non-greedy and use only the last matching lookbehind? [I hope I have translated this correctly from the NoteTab syntax. I don't do much RegEx coding. The <prefix>, <content> & <suffix> terms are just meant to represent arbitrary strings. Only the "<" in the "?<=" lookbehind command is significant.] I suspect it is something simple but after too many hours of searching I'm giving up on solving it myself. Thanks for the help Art

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  • Using an ORM with a database that has no defined relationships?

    - by Ahmad
    Consider a database(MSSQL 2005) that consists of 100+ tables which have primary keys defined to a certain degree. There are 'relationships' between tables, however these are not enforced with foreign key constraints. Consider the following simplified example of typical types of tables I am dealing with. The are clear relations between the User and City and Province tables. However, they key issues is the inconsistent data types in the tables and naming conventions. User: UserRowId [int] PK Name [varchar(50)] CityId [smallint] ProvinceRowId [bigint] City: CityRowId [bigint] PK CityDescription [varchar(100)] Province: ProvinceId [int] PK ProvinceDesc [varchar(50)] I am considering a rewrite of the application (in ASP.net MVC) that uses this data source as is similar in design to MVC storefront. However I am going through a proof of concept phase and this is one of the stumbling blocks I have come across. What are my options in terms of ORM choice that can be easily used and why? Should I even be considering an ORM? (The reason I ask this is that most explanations and tutorials all work with relatively cleanly designed existing databases, or newly created ones when compared to mine. I am thus having a very hard time trying to find a way forward with this problem) There is a huge amount of existing SQL queries, would a datamappper(eg IBatis.net) be more suitable since we could easily modify them to work and reuse the investment already made? I have found this question on SO which indicates to me that an ORM can be used - however I get the impression that this a question of mapping? Note: at the moment, the object model is not clearly defined as it was non-existent. The existing system pretty much did almost everything in SQL or consisted of overly complicated, and numerous queries to complete fucntionality. I am pretty much a noob and have zero experience around ORMs and MVC - so this an awesome learning curve I am on.

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  • Replacing characters in a non well-formed XML body

    - by ryanprayogo
    In a (Java) code that I'm working on, I sometimes deal with a non well-formed XML (represented as a Java String), such as: <root> <foo> bar & baz < quux </foo> </root> Since this XML will eventually need to be unmarshalled (using JAXB), obviously this XML as is will throw exception upon unmarshalling. What's the best way to replace the & and the < to its character entities? For &, it's as easy as: xml.replaceAll("&", "&amp;") However, for the < symbol, it's a bit tricky since obviously I don't want to replace the < that's used for the XML tag opening 'bracket'. Other than scanning the string and manually replacing < in the XML body with &lt;, what other option can you suggest?

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  • Database Rebuild

    - by Robert May
    I promised I’d have a simpler mechanism for rebuilding the database.  Below is a complete MSBuild targets file for rebuilding the database from scratch.  I don’t know if I’ve explained the rational for this.  The reason why you’d WANT to do this is so that each developer has a clean version of the database on their local machine.  This also includes the continuous integration environment.  Basically, you can do whatever you want to the database without fear, and in a minute or two, have a completely rebuilt database structure. DBDeploy (including the KTSC build task for dbdeploy) is used in this script to do change tracking on the database itself.  The MSBuild ExtensionPack is used in this target file.  You can get an MSBuild DBDeploy task here. There are two database scripts that you’ll see below.  First is the task for creating an admin (dbo) user in the system.  This script looks like the following: USE [master] GO If not Exists (select Name from sys.sql_logins where name = '$(User)') BEGIN CREATE LOGIN [$(User)] WITH PASSWORD=N'$(Password)', DEFAULT_DATABASE=[$(DatabaseName)], CHECK_EXPIRATION=OFF, CHECK_POLICY=OFF END GO EXEC master..sp_addsrvrolemember @loginame = N'$(User)', @rolename = N'sysadmin' GO USE [$(DatabaseName)] GO CREATE USER [$(User)] FOR LOGIN [$(User)] GO ALTER USER [$(User)] WITH DEFAULT_SCHEMA=[dbo] GO EXEC sp_addrolemember N'db_owner', N'$(User)' GO The second creates the changelog table.  This script can also be found in the dbdeploy.net install\scripts directory. CREATE TABLE changelog ( change_number INTEGER NOT NULL, delta_set VARCHAR(10) NOT NULL, start_dt DATETIME NOT NULL, complete_dt DATETIME NULL, applied_by VARCHAR(100) NOT NULL, description VARCHAR(500) NOT NULL ) GO ALTER TABLE changelog ADD CONSTRAINT Pkchangelog PRIMARY KEY (change_number, delta_set) GO Finally, Here’s the targets file. <Projectxmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0" DefaultTargets="Update">   <PropertyGroup>     <DatabaseName>TestDatabase</DatabaseName>     <Server>localhost</Server>     <ScriptDirectory>.\Scripts</ScriptDirectory>     <RebuildDirectory>.\Rebuild</RebuildDirectory>     <TestDataDirectory>.\TestData</TestDataDirectory>     <DbDeploy>.\DBDeploy</DbDeploy>     <User>TestUser</User>     <Password>TestPassword</Password>     <BCP>bcp</BCP>     <BCPOptions>-S$(Server) -U$(User) -P$(Password) -N -E -k</BCPOptions>     <OutputFileName>dbDeploy-output.sql</OutputFileName>     <UndoFileName>dbDeploy-output-undo.sql</UndoFileName>     <LastChangeToApply>99999</LastChangeToApply>   </PropertyGroup>     <ImportProject="$(MSBuildExtensionsPath)\ExtensionPack\4.0\MSBuild.ExtensionPack.tasks"/>   <UsingTask TaskName="Ktsc.Build.DBDeploy" AssemblyFile="$(DbDeploy)\Ktsc.Build.dll"/>   <ItemGroup>     <VariableInclude="DatabaseName">       <Value>$(DatabaseName)</Value>     </Variable>     <VariableInclude="Server">       <Value>$(Server)</Value>     </Variable>     <VariableInclude="User">       <Value>$(User)</Value>     </Variable>     <VariableInclude="Password">       <Value>$(Password)</Value>     </Variable>   </ItemGroup>     <TargetName="Rebuild">     <!--Take the database offline to disconnect any users. Requires that the current user is an admin of the sql server machine.-->     <MSBuild.ExtensionPack.SqlServer.SqlCmd Variables="@(Variable)" Database="$(DatabaseName)" TaskAction="Execute" CommandLineQuery ="ALTER DATABASE $(DatabaseName) SET OFFLINE WITH ROLLBACK IMMEDIATE"/>         <!--Bring it back online.  If you don't, the database files won't be deleted.-->     <MSBuild.ExtensionPack.Sql2008.DatabaseTaskAction="SetOnline" DatabaseItem="$(DatabaseName)"/>     <!--Delete the database, removing the existing files.-->     <MSBuild.ExtensionPack.Sql2008.DatabaseTaskAction="Delete" DatabaseItem="$(DatabaseName)"/>     <!--Create the new database in the default database path location.-->     <MSBuild.ExtensionPack.Sql2008.DatabaseTaskAction="Create" DatabaseItem="$(DatabaseName)" Force="True"/>         <!--Create admin user-->     <MSBuild.ExtensionPack.SqlServer.SqlCmd TaskAction="Execute" Server="(local)" Database="$(DatabaseName)" InputFiles="$(RebuildDirectory)\0002 Create Admin User.sql" Variables="@(Variable)" />     <!--Create the dbdeploy changelog.-->     <MSBuild.ExtensionPack.SqlServer.SqlCmd TaskAction="Execute" Server="(local)" Database="$(DatabaseName)" LogOn="$(User)" Password="$(Password)" InputFiles="$(RebuildDirectory)\0003 Create Changelog.sql" Variables="@(Variable)" />     <CallTarget Targets="Update;ImportData"/>     </Target>    <TargetName="Update" DependsOnTargets="CreateUpdateScript">     <MSBuild.ExtensionPack.SqlServer.SqlCmd TaskAction="Execute" Server="(local)" Database="$(DatabaseName)" LogOn="$(User)" Password="$(Password)" InputFiles="$(OutputFileName)" Variables="@(Variable)" />   </Target>   <TargetName="CreateUpdateScript">     <ktsc.Build.DBDeploy DbType="mssql"                                        DbConnection="User=$(User);Password=$(Password);Data Source=$(Server);Initial Catalog=$(DatabaseName);"                                        Dir="$(ScriptDirectory)"                                        OutputFile="..\$(OutputFileName)"                                        UndoOutputFile="..\$(UndoFileName)"                                        LastChangeToApply="$(LastChangeToApply)"/>   </Target>     <TargetName="ImportData">     <ItemGroup>       <TestData Include="$(TestDataDirectory)\*.dat"/>     </ItemGroup>     <ExecCommand="$(BCP) $(DatabaseName).dbo.%(TestData.Filename) in&quot;%(TestData.Identity)&quot;$(BCPOptions)"/>   </Target> </Project> Technorati Tags: MSBuild

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  • R ggplot2: Arrange facet_grid by non-facet column (and labels using non-facet column)

    - by tommy-o-dell
    I have a couple of questions regarding facetting in ggplot2... Let's say I have a query that returns data that looks like this: (note that it's ordered by Rank asc, Alarm asc and two Alarms have a Rank of 3 because their Totals = 1798 for Week 4, and Rank is set according to Total for Week 4) Rank Week Alarm Total 1 1 BELTWEIGHER HIGH HIGH 1000 1 2 BELTWEIGHER HIGH HIGH 1050 1 3 BELTWEIGHER HIGH HIGH 900 1 4 BELTWEIGHER HIGH HIGH 1800 2 1 MICROWAVE LHS 200 2 2 MICROWAVE LHS 1200 2 3 MICROWAVE LHS 400 2 4 MICROWAVE LHS 1799 3 1 HI PRESS FILTER 2 CLOG SW 1250 3 2 HI PRESS FILTER 2 CLOG SW 1640 3 3 HI PRESS FILTER 2 CLOG SW 1000 3 4 HI PRESS FILTER 2 CLOG SW 1798 3 1 LOW PRESS FILTER 2 CLOG SW 800 3 2 LOW PRESS FILTER 2 CLOG SW 1200 3 3 LOW PRESS FILTER 2 CLOG SW 800 3 4 LOW PRESS FILTER 2 CLOG SW 1798 (duplication code below) Rank = c(rep(1,4),rep(2,4),rep(3,8)) Week = c(rep(1:4,4)) Total = c( 1000,1050,900,1800, 200,1200,400,1799, 1250,1640,1000,1798, 800,1200,800,1798) Alarm = c(rep("BELTWEIGHER HIGH HIGH",4), rep("MICROWAVE LHS",4), rep("HI PRESS FILTER 2 CLOG SW",4), rep("LOW PRESS FILTER 2 CLOG SW",4)) spark <- data.frame(Rank, Week, Alarm, Total) Now when I do this... s <- ggplot(spark, aes(Week, Total)) + opts( panel.background = theme_rect(size = 1, colour = "lightgray"), panel.grid.major = theme_blank(), panel.grid.minor = theme_blank(), axis.line = theme_blank(), axis.text.x = theme_blank(), axis.text.y = theme_blank(), axis.title.x = theme_blank(), axis.title.y = theme_blank(), axis.ticks = theme_blank(), strip.background = theme_blank(), strip.text.y = theme_text(size = 7, colour = "red", angle = 0) ) s + facet_grid(Alarm ~ .) + geom_line() I get this.... Notice that it's facetted according to Alarm and that the facets are arranged alphabetically. Two Questions: How can I can I keep it facetted by alarm but displayed in the correct order? (Rank asc, Alarm asc). Also, how can I keep it facetted by alarm but show labels from Rank instead of Alarm? Note that I can't just facet on Rank because ggplot2 would see only 3 facets to plot where there are really 4 different alarms. Thanks kindly for the help! Tommy

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  • Crystal Reports Server - Database Login Needs to go Away

    - by Trey Sargent
    The environment I'm working in is a Crystal Reports Server 2008 talking to a MySQL Server 5.1 database using JDBC. The problem is that I get a database logon screen every time I try to access a report from Crystal Reports Server. I've setup a JDBC connection using the MySQL Connector/J driver. When I create a .rpt file I provide the login credentails all is fine. I then publish to InfoView and go to access the report and it prompts me for username and password to the database. I then went to CMC and right-clicked on the report and opened the Database Configuration. I've selected 'Use original database logon information from the report' and 'Use same database logon as when report is run'. However, I still get the logon screen when I try to access the report.

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  • Implicit conversion : const reference vs non-const reference vs non-reference

    - by Nawaz
    Consider this code, struct A {}; struct B { B(const A&) {} }; void f(B) { cout << "f()"<<endl; } void g(A &a) { cout << "g()" <<endl; f(a); //a is implicitly converted into B. } int main() { A a; g(a); } This compiles fine, runs fine. But if I change f(B) to f(B&), it doesn't compile. If I write f(const B&), it again compiles fine, runs fine. Why is the reason and rationale? Summary: void f(B); //okay void f(B&); //error void f(const B&); //okay I would like to hear reasons, rationale and reference(s) from the language specification, for each of these cases. Of course, the function signatures themselves are not incorrect. Rather A implicitly converts into B and const B&, but not into B&, and that causes the compilation error.

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  • Using a database class in my user class

    - by Josh
    In my project I have a database class that I use to handle all the MySQL stuff. It connects to a database, runs queries, catches errors and closes the connection. Now I need to create a members area on my site, and I was going to build a users class that would handle registration, logging in, password/username changes/resets and logging out. In this users class I need to use MySQL for obvious reasons... which is what my database class was made for. But I'm confused as to how I would use my database class in my users class. Would I want to create a new database object for my user class and then have it close whenever a method in that class is finished? Or do I somehow make a 'global' database class that can be used throughout my entire script (if this is the case I need help with that, no idea what to do there.) Thanks for any feedback you can give me.

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  • upgrading to worpdress 3.5 erased all posts and pages, wiped database

    - by James
    So I have upgraded to wordpress 3.5 and that seemed to have erased all posts and custom post types, media images, sliders etc' I have made a backup using both pressbackup and backupbuddy but when I try to restore the database (or everything). when it is done, if I look at the front end, everything is back and looks great but then when I go to the back end it says the database needs to be upgraded and doesn't let me bypass that. if i click ok it prompts the following message and after that everything is wiped again: WordPress database error: [Table 'db446353270.wp_categories' doesn't exist] SELECT * FROM wp_categories ORDER BY cat_ID WordPress database error: [Table 'db446353270.wp_post2cat' doesn't exist] SELECT post_id, category_id FROM wp_post2cat GROUP BY post_id, category_id WordPress database error: [Table 'db446353270.wp_linkcategories' doesn't exist] SELECT cat_id, cat_name FROM wp_linkcategories WordPress database error: [Unknown column 'link_category' in 'field list'] SELECT link_id, link_category FROM wp_links please advise. Thanks

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  • Ecommerce Database DNS Switch

    - by KThompson
    Hello, I am moving an e-commerce site to a new server. All has been successful and its time to change the DNS for the domain. It's a relatively popular site and I fear that during propagation orders will be split between the old database and the new one. The databases do contain content that is dependent of the server it is on (Cache path, upload directory, etc.) so I can't just point the old site to the new database. Are there any solutions to this without any of the sites going down. Thanks in advance

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  • Set up Glassfish connection pool to talk to a database on a Ubuntu VPS

    - by Harry Pham
    On my Ubuntu VPS, i have a mysql server running and a Glassfish 3.0.1 Application Server running. And I am having a hard to have my GF successfully ping the database. Here is my GF set up Assume: x.y.z.t is the ip of my VPS Resource Type: javax.sql.ConnectionPoolDataSource User: root DatabaseName: scholar Url: jdbc:mysql://x.y.z.t:3306/scholar URL: jdbc:mysql://x.y.z.t:3306/scholar Password: xxxx PortNumber: 3306 ServerName: x.y.z.t Inside my glassfish3/glassfish/lib, I have my mysql-connector-java-5.1.13-bin.jar Inside the database, table mysql here is the result of the query select User, Host from user; +------------------+-----------+ | User | Host | +------------------+-----------+ | root | 127.0.0.1 | | debian-sys-maint | localhost | | root | localhost | | root | yunaeyes | +------------------+-----------+ Now from my machine, if I try to connect to this db via mysql browser (mysql client software), well I cant. Well from the table above, seem like it only allow localhost to connect to this db. Keep in mind that both my db and my GF are on the same VPS. Please help

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  • What are appropriate ways to represent relationships between people in a database table?

    - by Emilio
    I've got a table of people - an ID primary key and a name. In my application, people can have 0 or more real-world relationships with other people, so Jack might "work for" Jane and Tom might "replace" Tony and Bob might "be an employee of" Rob and Bob might also "be married to" Mary. What's the best way to represent this in the database? A many to many intersect table? A series of self joins? A relationship table with one row per relationship pair and type, where I insert records for the relationship in both directions?

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  • Convert a MSSQL database to MYSQL database

    - by soldieraman
    Alright so I want to convert an already exist MSSQL database (2005) to a MYSQL database. There is nothing extraordinary to be done The only things I need to achieve is Recreate the tables Transfer data Relationships would be nice but not necessary No views, no sprocs, no functions. Any easy way to do this. Also do you know of any DST (Database Synchronization Tool) which would let me do MSSQL to MYSQL MYSQL to MYSQL MSSQL to MSSQL (I know there is SQL Delta for this)

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