How to use Enum, Properties and string compare

using System;
using System.Collections.Generic;

namespace Workshop
{
    public enum Grades
    {
        Fail,
        Pass,
        FirstClass,
        Distinction
    }
    //class variable or members
    public class Student
    {
        //Define simple properties
        public string Name { get; set; }
        public int TotalMarks { get; set; }
        public string Course { get; set; }
        //read only complex property
        public Grades PassingGrades
        {
            get
            {
                if (TotalMarks >= 80)
                    return Grades.Distinction;
                else if (TotalMarks >= 60)
                    return Grades.FirstClass;
                else if (TotalMarks >= 50)
                    return Grades.Pass;
                else
                    return Grades.Fail;
            }
        }
       
        //Definte complex properties
    }
    class Program
    {
        static void Main(string[] args)
        {
            //prepare few student objects
            Student st1 = new Student();
            st1.Name = "Adrian";
            st1.Course = "EWS";
            st1.TotalMarks = 80;
            Student st2 = new Student();
            st2.Name = "Ross";
            st2.Course = "AA";
            st2.TotalMarks = 60;
            //simple collection of Student objects
            List allStudents = new List();
            allStudents.Add(st1);
            allStudents.Add(st2);
            //now print grades of all EWS student
            foreach (var st in allStudents)
            {
                //string compare
                if (st.Course.Equals("EWS"))
                {
                    //this is how we use enum
                    Console.WriteLine(st.Name  + " " + st.PassingGrades);
                }
            }

            //now print AA studets
            //this is simple java like loop
            for (int i = 0; i < allStudents.Count; i++)
            {
                //string compare in differnt way
                if (allStudents[i].Course == "AA")
                {
                    //use enum to print
                    Console.WriteLine(allStudents[i].Name + " " + allStudents[i].PassingGrades);
                }
            }
            Console.Read();
        }
    }
}

C# Currency Converter using Google API

//A very simple currency converter using google API.
private decimal GoogleCurrencyConverter(string fromCurrency, string toCurrency)
    {
        WebClient web = new WebClient();

        string url = string.Format("https://www.google.com/finance/converter?a=1&from={0}&to={1}", fromCurrency.ToUpper(), toCurrency.ToUpper());

        string response = web.DownloadString(url);

        Regex regex = new Regex("(\\d*.\\d*)");
        var r = regex.Match(response);

        return Convert.ToDecimal(r.Groups[1].Value);
    }

Currency Converter via XML web service

//add webservice http://www.webservicex.net/country.asmx

WebServiceX.country client = new WebServiceX.country();

var currencies = client.GetCurrencies();

//Convert the XML result into dataset/table

DataSet ds = new DataSet();

ds.ReadXml(new System.Xml.XmlTextReader(new StringReader(currencies)));

string name = null;

string code = null;

//name & country code.
foreach (DataRow r in ds.Tables[0].Rows)
{
    name = r["Name"].ToString();
    code = r["CountryCode"].ToString();

    Console.WriteLine(name + " " + code);
}

How to Send document from website to client C#

///default.aspx

<%@ Page Title="Home Page" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeadContent">

</asp:Content>

<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">

    <h2>
        Testing opening word document from webpage.
    </h2>
    <asp:Button runat="server" ID="btnStart" Text="Click here" onclick="btnStart_Click"/>
   </p>
</asp:Content>

//default.aspx.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
 
    }
    protected void btnStart_Click(object sender, EventArgs e)
    {
        Response.Clear();
        Response.AddHeader("content-disposition", "attachment;filename=Test.docx");
        Response.ContentType = "application/ms-word";
             //If you have sharepoint path then change here..
        Response.TransmitFile(Server.MapPath("test.docx"));
        Response.Flush();
        Response.End();
    }

}

 

 

MySql set password for "root" user

How to set password for 'root' users on mysql

1. Start mysqld with below option
2. c:> mysqld --defaults-file=c:\mysqlc\my.ini --console --skip-grant-tables

1. start mysql client
2. use mysql
3. update user set password=PASSWORD('newpassword') where user='root"
4. FLUSH PRIVILEGES

restart mysqld without --skip-grant-tables option.. thats all

MySql cluster and Java

Pre-requisites

• ClusterJ API : ClusterJ is a high level database API that is similar in style and concept to object-relational mapping persistence frameworks such as Hibernate and JPA
• Requires below jar files
  openjpa-1.2.0.jar
driver-5.1.10.jar (This is the MySQL JDBC driver)
  geronimo-jta_1.1_spec-1.1.jar
geronimo-jpa_3.0_spec-1.0.jar
serp-1.13.1.jar
commons-lang-2.1.jar
commons-collections-3.2.jar
  clusterj-api.jar
  clusterj.jar
  clusterjpa.jar

Code

import com.mysql.clusterj.annotation.Column;
import com.mysql.clusterj.annotation.Index;
import com.mysql.clusterj.annotation.PersistenceCapable;
import com.mysql.clusterj.annotation.PrimaryKey;

//sample code

Properties props = new Properties();

//replace localhost with managment node hostname
props.put("com.mysql.clusterj.connectstring", "localhost:1186");

//replace mydb with your database name.
props.put("com.mysql.clusterj.database", "mydb");

References:

http://www.clusterdb.com/mysql-cluster/using-clusterj-part-of-mysql-cluster-connector-for-java-a-tutorial/

MySQL Cluster on Windows my way

Welcome to crash mysql cluster master page :-)

Lets plan to implement it this way.

Node	IP Address
Management (MGMD) node	192.168.0.10
MySQL server (SQL) node	192.168.0.20
Data (NDBD) node "A"	192.168.0.30
Data (NDBD) node "B"	192.168.0.40

Precautions: Always use forward slashesh or 2 backward slasesh for specifying the paths in config or ini files.

Step 1: Download and install (on sqlnode host or 192.168.0.20)

• Download Binaries here http://dev.mysql.com/downloads/cluster/
•  Extract the zip to c:\mysql directory. If you put into c drive you will need admin rights to start management console. If you put in c:\users\\mysqlc you dont need admin rights to start anything so choice is yours.
  Note: Basically you need full rights on the directory.
• Add path c:\mysql\bin to Environment Variable.
• leave this and come back on step 3

Step 2: Setup management node

• Create c:\mysql\bin directory
• copy ndb_mgmd.exe and ndb_mgm.exe in c:\mysql\bin from sqlnode host
  
  > Note: we just need these executables on management node.
• Create local configuration file my.ini - this file needs only to supply the location of configuration file
  
  [mysql_cluster]
  # options for manangement node process
  #config-file=c:/mysql/bin/config.ini
• Create configuration file config.ini with below content and save to c:\mysql\bin

[ndbd default]
NoOfReplicas=2
DataDir=C:/mysql/bin/cluster-data

[ndb_mgmd]
HostName=192.168.0.10               # Hostname or IP address of management node
DataDir=C:/mysql/bin/cluster-logs   # Directory for management node log files

[ndbd]
# Options for data node "A":  # (one [ndbd] section per data node)
HostName=192.168.0.30           # Hostname or IP address

[ndbd]
# Options for data node "B":
HostName=192.168.0.40           # Hostname or IP address

[mysqld]
# SQL node options:
HostName=192.168.0.20           # Hostname or IP address


Step 3: Setup sql node

•  create c:\mysql\my.ini with below content

[mysqld]
# Options for mysqld process:
ndbcluster                      # run NDB storage engine
ndb-connectstring=192.168.0.10  # location of management server

#use different port if you already have mysql server running or uncomment below
port=5000

#provide basedir and datadire if they are not in c:\ drive
basedir=c:/mysql
datadir=c:/mysql/data

Step 4: Setup Data nodes

Follow the below steps on data node hosts.

• Create c:\mysql and c:\mysql\bin and c:\mysql\bin\cluster-data directory
• Copy ndbd.exe from (192.168.0.20) into c:\bin
  Note: we just need this executable and nothing else for data node.
• Create my.ini into c:\mysql\my.ini and add below content
  
  [mysql_cluster]
  # Options for data node process:
  ndb-connectstring=192.168.0.10  # location of management server

Step 4: Start the cluster.

• 1st start managment nodec:\mysql\bin> ndb_mgmd -f config.ini [--initial]
  Important: management node cashes the configuration data that it reads from config.ini. If you make any changes in configuration you must provide --reload option or --initial option to realod the configuration otherwise the -f config.ini option will be ignored from 2nd run onward
  Note: remove "[" and "]" if you are using the --initial option
  Note: -f or --config-file is same.Important: By default cluster create configuration cache in c:\mysql\bin\mysql-cluster directory but you can override with --configdir option.
• 2nd start data nodesc:\mysql\bin> ndbdNote: as long as you are running the process from bin directory and your my.ini file is in the bin directory you dont need provide any path.
• Start Node Manager to see what's going on..c:\mysql\bin> ndb_mgmndb_mgm> show ndb_mgm>ALL STATUS
• finally, start sql nodec:\mysql\bin>mysqld --console
  
  Note: console option provide more details and can be used for debugging purpose. Again as long as you keep the my.ini in the bin directory you dont need provide any path.

Known Errors & Resolutions.

• If data nodes are stopping then Start node with --initial parameter, ie. >ndbd --initial
• If data directory are stored in different location than default binary location

Debugging

• The below option "--console" provides debugging information when used with mysqld
  
  c:\mysql\> mysqld --console
• 
  

References:

• http://downloads.mysql.com/tutorials/cluster/mysql_wp_cluster_quickstart_windows.pdf
• http://dev.mysql.com/doc/mysql-cluster-excerpt/5.1/en/index.html
• http://dev.mysql.com/doc/refman/5.0/en/create-table.html  
• http://dev.mysql.com/doc/refman/5.0/en/connector-j-reference-configuration-properties.html
• http://waterlovinghead.com/MysqlJDBCFailover 
• https://blogs.oracle.com/carriergrademysql/entry/how_to_use_jdbc_connector

How to Display time in Different Timezones

Specific Example: How to display current time for Rio De Janeiro?

1. Find out the timezone abbreviation or name from here http://www.timeanddate.com/worldclock/city.html?n=213
   Timezone abbreviation: BRT – Brasilia time
2. Find out the mapping of correct standard name for the above timezone. http://msdn.microsoft.com/en-us/library/ms912391(v=winembedded.11).aspx
   

   065

   E. South America Standard Time

   (GMT-03:00) Brasilia

3. Now we can use the code to set timezone to E. South America Standard Time

here is the code sample.

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;

namespace Timezone
{
    class Program
    {
        static void Main(string[] args)
        {
            System.Console.WriteLine("Local time:" + DateTime.Now.ToString());

            var brazilTime = TimeZoneInfo.ConvertTime(DateTime.Now, TimeZoneInfo.FindSystemTimeZoneById("E. South America Standard Time"));
            
            System.Console.WriteLine("Brazil Time:\t" + brazilTime.ToString());
            
            System.Console.ReadLine();
        }
    }
}