3.4 CRUD Operations

// Create Collection
Collection weatherStationCol =
		store.putCollection("weather_station", WeatherStation.class);
return weatherStationCol;

// Set the value to Row data
WeatherStation weatherStation1 = new WeatherStation ();
weatherStation1.id = "1";
weatherStation1.name = "WeatherStation 01";
weatherStation1.latitude = 35.68944;
weatherStation1.longitude = 139.69167;
weatherStation1.hasCamera = true;

WeatherStation weatherStation2 = new WeatherStation ();
weatherStation2.id = "2";
weatherStation2.name = "WeatherStation 02";
weatherStation2.latitude = 35.02139;
weatherStation2.longitude = 135.75556;
weatherStation2.hasCamera = false;

// Register Collection
weatherStationCol.put (weatherStation1);
weatherStationCol.put (weatherStation2);

// Retrieve Collection
System.out.println("get by key");
System.out.println("ID\tName\t\t\tLongitude\tLatitude\tCamera");
weatherStationCol = store.getCollection("weather_station", WeatherStation.class);

for (int i = 0; i <2; i ++) {
	WeatherStation weatherStation = weatherStationCol.get (String.valueOf (i + 1));
	System.out.println (String.format("% - 3s\t% -20s\t% s\t% s\t% -5s", weatherStation.id,
			weatherStation.name, weatherStation.latitude, weatherStation.longitude,
			weatherStation.hasCamera));
}

get by key
ID Name Longitude Latitude Camera
1 WeatherStation 01 35.68944 139.69167 true
2 WeatherStation 02 35.02139 135.75556 false

Container.dropCollection (String)

TQL

Put simply, TQL is a simplified SQL prepared for NoSQL products. The support range is limited to functions such as search, aggregation, etc. TQL is employed by using the client API (Java, C language). To register and search for data in GridDB, a container or table (NewSQL products only) needs to be created to store the data. This section describes the data types that can be registered in a container or table, data size, index and data management functions.

The naming rules for containers and tables are the same as those for databases.

• A string consisting of alphanumeric characters and the underscore mark can be specified. However, the first character cannot be a number.
• Although the case sensitivity of the name is maintained, a container (table) which has the same name when it is not case-sensitive cannot be created.

Container Creation

Container (collection)	
createcollection	Container name Column name Type [Column name Type …]
Container (time series container)	
createtimeseries	Container name Compression method Column name type [Column name Type …]

　　Example: When using the output metadata file as a container definition file

{
	"version":"2.1.00",　　　　　　　　　　　　　　　←invalid
	"container":"container_354",
	"database":"db2",　　　　　　　　　　　　　　　　←invalid
	"containerType":"TIME_SERIES",
	"containerFileType":"binary",　　　　　　　　　　←invalid
	"containerFile":"20141219_114232_098_div1.mc", 　←invalid
	"rowKeyAssigned":true,
	"partitionNo":0,　　　　　　　　　　　　　　　　 ←invalid
	"columnSet":[
		{
			"columnName":"timestamp",
			"type":"timestamp"
		},
		{
			"columnName":"active",
			"type":"boolean"
		},
		{
			"columnName":"voltage",
			"type":"double"
		}
	],
	"timeSeriesProperties":{
		"compressionMethod":"NO",
		"compressionWindowSize":-1,
		"compressionWindowSizeUnit":"null",
		"expirationDivisionCount":8,
		"rowExpirationElapsedTime":-1,
		"rowExpirationTimeUnit":"null"
	},
	"compressionInfoSet":[
	]

Container Deletion

• Example:

  gs[public]> dropcontainer　Con001

Container Indication

The following command is used to display the container data.

• Sub-command

  showcontainer

  Container name

• Description of each argument

  Argument	Description
  Container name	Specify the container name to be displayed. Display a list of all containers if omitted.

• Example:

  // display container list
  gs[userDB]> showcontainer
  Database : userDB
  Name                  Type         PartitionId
  ------------------------------------------------
  cont001               COLLECTION            10
  col00a                COLLECTION             3
  time02                TIME_SERIES            5
  cont003               COLLECTION            15
  cont005               TIME_SERIES           17
  
  // display data of specified container
  gs[public]> showcontainer cont003
  Database    : userDB
  Name : cont003
  Type : COLLECTION
  Partition ID: 15
  DataAffinity: -
  
  Columns:
  No  Name                  Type            Index
  ------------------------------------------------------------
  0  col1                  INTEGER         [TREE] (RowKey)
  1  col2                  STRING          []
  2  col3                  TIMESTAMP       []
  

[Memo]

• The data displayed in a container list are the “Container name”, “Container type” and “Partition ID”.
• The data displayed in the specified container are the “Container name”, “Container type”, “Partition ID”, “Defined column name”, “Column data type” and “Column index setting”.
• Container data of the current DB will be displayed.

Container ROWKEY

A ROWKEY is the data set in the row of a container. The uniqueness of a row with a set ROWKEY is guaranteed. A ROWKEY can be set in the first column of the row. (This is set in Column No. 0 since columns start from 0 in GridDB.)

• For a timeseries container
• ROWKEY is a TIMESTAMP
• Must be specified.

• For a collection container
• A ROWKEY is either a STRING, INTEGER, LONG, or TIMESTAMP column.
• Need not be specified

A default index prescribed in advance according to the column data type can be set in a column set in ROWKEY. In the current version, the default index of all STRING, INTEGER, LONG or TIMESTAMP data that can be specified in a ROWKEY is the TREE index.

Sample of Collection Operations (Java)

package test;


import java.util.Arrays;
import java.util.Properties;

import com.toshiba.mwcloud.gs.Collection;
import com.toshiba.mwcloud.gs.GSException;
import com.toshiba.mwcloud.gs.GridStore;
import com.toshiba.mwcloud.gs.GridStoreFactory;
import com.toshiba.mwcloud.gs.Query;
import com.toshiba.mwcloud.gs.RowKey;
import com.toshiba.mwcloud.gs.RowSet;


// Operaton on Collection data
public class Sample1 {

	static class Person {
		@RowKey String name;
		boolean status;
		long count;
		byte[] lob;
	}

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

		// Get a GridStore instance
		Properties props = new Properties();
		props.setProperty("notificationAddress", args[0]);
		props.setProperty("notificationPort", args[1]);
		props.setProperty("clusterName", args[2]);
		props.setProperty("user", "system");
		props.setProperty("password", "manager");
		GridStore store = GridStoreFactory.getInstance().getGridStore(props);

		// Create a Collection (Delete if schema setting is NULL)
		Collection<String, Person> col = store.putCollection("col01", Person.class);

		// Set an index on the Row-key Column
		col.createIndex("name");

		// Set an index on the Column
		col.createIndex("count");

		// Set the autocommit mode to OFF
		col.setAutoCommit(false);

		// Prepare data for a Row
		Person person = new Person();
		person.name = "name01";
		person.status = false;
		person.count = 1;
		person.lob = new byte[] { 65, 66, 67, 68, 69, 70, 71, 72, 73, 74 };

		// Operate a Row on a K-V basis: RowKey = "name01"
		boolean update = true;
		col.put(person);	// Add a Row
		person = col.get(person.name, update);	// Obtain the Row (acquiring a lock for update)
		col.remove(person.name);	// Delete the Row

		// Operate a Row on a K-V basis: RowKey = "name02"
		col.put("name02", person);	// Add a Row (specifying RowKey)

		// Commit the transaction (Release the lock)
		col.commit();

		// Search the Collection for a Row
		Query<Person> query = col.query("select * where name = 'name02'");

		// Fetch and update the searched Row
		RowSet<Person> rs = query.fetch(update);
		while (rs.hasNext()) {
			// Update the searched Row
			Person person1 = rs.next();
			person1.count += 1;
			rs.update(person1);

			System.out.println("Person: " +
					" name=" + person1.name +
					" status=" + person1.status +
					" count=" + person1.count +
					" lob=" + Arrays.toString(person1.lob));
		}

		// Commit the transaction
		col.commit();

		// Release the resource
		store.close();
	}

}

Sample of TimeSeries Operations 0 Storage and Extraction of Specific Range (Java)

package test;


import java.util.Date;
import java.util.Properties;

import com.toshiba.mwcloud.gs.GSException;
import com.toshiba.mwcloud.gs.GridStore;
import com.toshiba.mwcloud.gs.GridStoreFactory;
import com.toshiba.mwcloud.gs.RowKey;
import com.toshiba.mwcloud.gs.RowSet;
import com.toshiba.mwcloud.gs.TimeSeries;
import com.toshiba.mwcloud.gs.TimestampUtils;
import com.toshiba.mwcloud.gs.TimeUnit;


// Storage and extraction of a specific range of time-series data
public class Sample2 {

	static class Point {
		@RowKey Date timestamp;
		boolean active;
		double voltage;
	}

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

		// Get a GridStore instance
		Properties props = new Properties();
		props.setProperty("notificationAddress", args[0]);
		props.setProperty("notificationPort", args[1]);
		props.setProperty("clusterName", args[2]);
		props.setProperty("user", "system");
		props.setProperty("password", "manager");
		GridStore store = GridStoreFactory.getInstance().getGridStore(props);

		// Create a TimeSeries (Only obtain the specified TimeSeries if it already exists)
		TimeSeries<Point> ts = store.putTimeSeries("point01", Point.class);

		// Prepare time-series element data
		Point point = new Point();
		point.active = false;
		point.voltage = 100;

		// Store the time-series element (GridStore sets its timestamp)
		ts.append(point);

		// Extract the specified range of time-series elements: last six hours
		Date now = TimestampUtils.current();
		Date before = TimestampUtils.add(now, -6, TimeUnit.HOUR);

		RowSet<Point> rs = ts.query(before, now).fetch();

		while (rs.hasNext()) {
			point = rs.next();

			System.out.println(
					"Time=" + TimestampUtils.format(point.timestamp) +
					" Active=" + point.active +
					" Voltage=" + point.voltage);
		}

		// Release the resource
		store.close();
	}

}