Install sbt on openSUSE Tumbleweed

Steps:

  1. Open yast2 and add sbt repo: https://bintray.com/sbt/rpm/rpm.
  2. Search for sbt in yast tool.
  3. Install the selected software. Unless there was an error, you are set.
  4. Check sbt installation by typing commands in terminal: sbt –version or sbt about
  5. If you get successful results, then you are set. Else follow the error prompts to fix the issue.

These simple steps will save you some time if you are working on openSUSE or rpm based systems.

Start with Pentaho Kettle

Quick steps to start using Pentaho Kettle Data Integration tool (Community Edition).

Pentaho Community 6.0 uses Java 1.7. Make sure Java 1.7 is installed on machine before starting working with this tool.

Steps to start:

  1. Download the community edition data integration tool.
  2. Extract and move it to a specific folder. It works like eclipse.
  3. Download the connector (.jar files) for database such MySQL. Move connector library to lib folder of Pentaho.
  4. Start spoon.sh for linux and spoon.bat for windows machine.
  5. Create a new connection using connection wizard. Test connection. Unless software reports any error, you are ready to create data transformation services.

Database backup in mysql using terminal

I usually prefer MySQL workbench to take backups and restore them. But sometimes circumstances bring forward a machine that doesn’t contain workbench. Use command line utility in that case. These backups/dumps are nothing but SQL statements.

mysqldump -u[username] -p [database_name]>[filename].sql

To restore a backup.

mysql -u[username] -p  [database_name] <[file_name].sql

If database name is not known then log into MySQL and find database using

show databases;

What is “Host” key in Ubuntu

Right cntr key on your keyboard is default host key on ubuntu systems.

Problem: After updating ubuntu on oracle virtualbox, my menu bar stopped displaying.

solution: After annoyingly trying to search it in virtualbox settings and image settings, I finally found the solution. Press Host+c key and your will see the menu bar. Never realized that you have full screen and scaled mode on virtual box.

Some helpful tips for Ruby on rails setup on fedora 21

1) Install RVM \curl -sSL https://get.rvm.io | bash -s stable

2) Install ruby dependencies and ruby older version.

rvm install 1.8.7 rvm use 1.8.7 –default if use doesn’t work, then get reload rvm and try again.

rvm get stable rvm use 2.0.0 –default

3) Go this url and install mysql http://dev.mysql.com/doc/mysql-repo-excerpt/5.6/en/linux-installation-yum-repo.html

mysql configuration : $ mysql_secure_installation

4) Sometimes rjb installation will fail because of java home path.

check java requirement for each rjb (ruby java bridge).

1.4.9 uses  Java 1.8,

to set path for JAVA_HOME export JAVA_HOME=”/etc/alternatives/java_sdk_1.8.0″

4.1) Install mysql2 gem -v 0.3.16

first : sudo yum install mysql-devel

second: gem install mysql2 -v 0.3.16

4.2) first :sudo yum install postgresql-libs postgresql-devel

second: gem install pg -v 0.17.1

5) If rake gives error, then install rake. go to project folder, uninstall rake, then do bundle update.

If rake gives error, then use help from this url:

http://stackoverflow.com/questions/21066301/cannot-load-rails-app-fetched-from-github-rake-rails-server-not-working

http://stackoverflow.com/questions/7838858/cannot-install-older-version-of-rake-gem-in-rails

HttpHandlers!! What are they?

There are many features in asp.net that are left unused, much because, developers don’t know when to use them. Such a feature is HttpHandlers.

When a request is made to IIS for an asp.net resource, like, .aspx, .ascx, etc, the asp.net worker process internally creates an instance of right HttpHandler for the request and effectively hands off the task of responding to the request. In Configuration files, paths are mapped to HttpHandlers for each kind of resource.

An HttpHandler is any class that implements System.Web.IHttpHandler interface. This interface provides a method ProcessRequest that process all the requests that are given to HttpHandlers. A quick note, PageHandlerFactory (Default Handler for .aspx) implements IPageHandlerFactory, instead of IHttpHandlers but it have a method GetHandler, which returns an instance of HttpHandler.  System.Web.UI.Page also implements this handler to process all the requests that comes to a aspx page.

Uses: Almost anything you want to do using custom HttpHandler can be done using Handler implemented in System.Web.UI.Page. But sometimes you may not want to fire all the events associated with a Page method, so you can use custom Handlers.

No Use: HttpHandlers can be used to handle extensions specified in IIS only.

Access Output parameter in DAL in DNN

To keep the story short and simple.
In DNN, sqldataprovider class, you can write a function like this.

public override bool CreateItem(string itemname)
{
SqlParameter[] parameter = new SqlParameter[2];
parameter[0] = new SqlParameter(“@itemname”, itemname);
        parameter[1] = new SqlParameter(“@isadded”, SqlDbType.Bit);
parameter[1].Direction = ParameterDirection.Output;

SqlHelper.ExecuteNonQuery(ConnectionString, CommandType.StoredProcedure,     NamePrefix + “sp_insertitem”, parameter);
if ((bool)parameter[1].Value)
return true;//insert successful
else
return false;//insert fail.
}