= 新 hbase 解析 =
 * hbase 已經到0.19.3了，可惜的是 hbase 0.18.1的api及文件都已經從官方網頁被拿掉了，所幸hbase 0.18 與hbase 0.19相差無幾
 * hbase 0.1.3 到 hbase 0.19.3 中間好像已經包含了十幾代，但是其實類似java 1.4 直接跳躍 到 java 5 一樣，hbase 0.1.3 -> hbase 0.2.x -> hbase 0.18.x -> hbase 0.19.x 
   * 從 hbase 0.18.x 之後，其版本名稱就直接對應hadoop 的版本名稱，如 hbase 0.18 搭配 hadoop 0.18 ， hbase 0.19 搭配hadoop 0.19

== 差別 ==
筆者開發hbase時是 hbase 0.13的時代，現在又重拾舊業，發現已經差很多了。

 === 找資料： ===
   * hbase 0.13 : select * from 'table_name'
   * hbase 0.19 : scan 'table_name'
 === 資料庫結構： ===
   * hbase 0.13 :
|| || column_family:column_quolify1|| column_family:column_quolify2|| column_family:column_quolify3||
|| time stamp 2 || cell_value1 || cell_value2|| cell_value3||
|| time stamp 1 || cell_value1 || cell_value2|| cell_value3||
   * hbase 0.19 : 加入 row 這個結構

 == 程式碼 ==

 * 定義宣告以下參數

{{{
		String table_name = "waue"; 
		String colomn_family = "family:";
		String column_quolify= "qf";
		String hbase_row = "w-row";
		String value = "0911311311";
}}}

 * 首先，建立config 物件與admin 物件，前者用來設定資料表屬性，後者用來執行資料庫的建立刪除操作

{{{
#!java

		HBaseConfiguration config = new HBaseConfiguration();
		HBaseAdmin admin = new HBaseAdmin(config);
}}}

 * 

{{{
#!java

		if (!admin.tableExists(table_name)) {
			System.out.println("HTable : " + table_name
					+ "  creating ... please wait");
			HTableDescriptor tableDesc = new HTableDescriptor(table_name);
			// add column family
			tableDesc.addFamily(new HColumnDescriptor(colomn_family));
			admin.createTable(tableDesc);
		}
}}}

 * 

{{{
#!java

		
		BatchUpdate batchUpdate = new BatchUpdate(hbase_row);
		batchUpdate.put(colomn_family+column_quolify, Bytes.toBytes(value));
		batchUpdate.delete(colomn_family+"cellIWantDeleted");
}}}

 * 

{{{
#!java
                HTable table = new HTable(config, table_name);
		table.commit(batchUpdate);
}}}

 * 

{{{
#!java

		Cell cell = table.get(hbase_row, colomn_family+column_quolify);
		System.out.print(cell.getValue());

}}}

 * 

{{{
#!java
		Scanner scanner =
		table.getScanner(new String[] { colomn_family+column_quolify });

		RowResult rowResult = scanner.next();

		while (rowResult != null) {

			System.out.println("Found row: "
					+ Bytes.toString(rowResult.getRow())
					+ " with value: "
					+ rowResult.get(Bytes
							.toBytes(colomn_family+column_quolify)));
			rowResult = scanner.next();
		}

		for (RowResult result : scanner) {
			System.out.println("Found row: "
					+ Bytes.toString(rowResult.getRow())
					+ " with value: "
					+ rowResult.get(Bytes
							.toBytes(colomn_family+column_quolify)));
		}

		scanner.close();



}}}


 * 完整程式碼如下

{{{
#!java
import java.io.IOException;

import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Scanner;
import org.apache.hadoop.hbase.io.BatchUpdate;
import org.apache.hadoop.hbase.io.Cell;
import org.apache.hadoop.hbase.io.RowResult;
import org.apache.hadoop.hbase.util.Bytes;

public class hbase {

	public static void main(String args[]) throws IOException {

		String table_name = "waue"; 
		String colomn_family = "family:";
		String column_quolify= "qf";
		String hbase_row = "w-row";
		String value = "0911311311";
		
		HBaseConfiguration config = new HBaseConfiguration();


		HBaseAdmin admin = new HBaseAdmin(config);
		if (!admin.tableExists(table_name)) {
			System.out.println("HTable : " + table_name
					+ "  creating ... please wait");
			HTableDescriptor tableDesc = new HTableDescriptor(table_name);
			// add column family
			tableDesc.addFamily(new HColumnDescriptor(colomn_family));
			admin.createTable(tableDesc);
		}

		HTable table = new HTable(config, table_name);


		BatchUpdate batchUpdate = new BatchUpdate(hbase_row);


		batchUpdate.put(colomn_family+column_quolify, Bytes
				.toBytes(value));


		batchUpdate.delete(colomn_family+"cellIWantDeleted");


		table.commit(batchUpdate);


		Cell cell = table.get(hbase_row, colomn_family+column_quolify);
		System.out.print(cell.getValue());


		Scanner scanner =
		table.getScanner(new String[] { colomn_family+column_quolify });

		RowResult rowResult = scanner.next();

		while (rowResult != null) {

			System.out.println("Found row: "
					+ Bytes.toString(rowResult.getRow())
					+ " with value: "
					+ rowResult.get(Bytes
							.toBytes(colomn_family+column_quolify)));
			rowResult = scanner.next();
		}

		for (RowResult result : scanner) {
			System.out.println("Found row: "
					+ Bytes.toString(rowResult.getRow())
					+ " with value: "
					+ rowResult.get(Bytes
							.toBytes(colomn_family+column_quolify)));
		}

		scanner.close();
	}
}


}}}