This chapter explains how to connect to a particular database from the OrientDB command line. It opens a database.

The following statement is the basic syntax of the Connect command.

CONNECT <database-url> <user> <password>

Following are the details about the options in the above syntax.

<database-url> − Defines the URL of the database. URL contains two parts one is <mode> and the second one is <path>.

<mode> − Defines the mode, i.e. local mode or remote mode.

<path> − Defines the path to the database.

<user> − Defines the user you want to connect to the database.

<password> − Defines the password for connecting to the database.

Example

We have already created a database named ‘demo’ in the previous chapters. In this example, we will connect to that using the user admin.

You can use the following command to connect to demo database.

orientdb> CONNECT PLOCAL:/opt/orientdb/databases/demo admin admin

If it is successfully connected, you will get the following output −

Connecting to database [plocal:/opt/orientdb/databases/demo] with user ''admin''…OK
Orientdb {db = demo}>

This chapter explains how to get information of a particular database from the OrientDB command line.

The following statement is the basic syntax of the Info command.

info

Note − You can use this command only after connecting to a particular database and it will retrieve the information of only the currently running database.

Example

In this example, we will use the same database named ‘demo’ that we created in the previous chapter. We will retrieve the basic information from demo database.

You can use the following command to disconnect the database.

orientdb {db = demo}> info

If it is successfully disconnected, you will get the following output.

Current database: demo (url = plocal:/opt/orientdb/databases/demo)

DATABASE PROPERTIES
--------------------------------+---------------------------------------------+
 NAME                           | VALUE                                       |
--------------------------------+---------------------------------------------+
 Name                           | null                                        |
 Version                        | 14                                          |
 Conflict Strategy              | version                                     |
 Date format                    | yyyy-MM-dd                                  |
 Datetime format                | yyyy-MM-dd HH:mm:ss                         |
 Timezone                       | Asia/Kolkata                                |
 Locale Country                 | IN                                          |
 Locale Language                | en                                          |
 Charset                        | UTF-8                                       |
 Schema RID                     | #0:1                                        |
 Index Manager RID              | #0:2                                        |
 Dictionary RID                 | null                                        |
--------------------------------+---------------------------------------------+

DATABASE CUSTOM PROPERTIES:
 +-------------------------------+--------------------------------------------+
 | NAME                          | VALUE                                      |
 +-------------------------------+--------------------------------------------+
 | strictSql                     | true                                       |
 +-------------------------------+--------------------------------------------+
CLUSTERS (collections)
---------------------------------+-------+-------------------+----------------+
 NAME                            | ID    | CONFLICT STRATEGY | RECORDS        |
---------------------------------+-------+-------------------+----------------+

This chapter explains how to get the list of all databases in an instance from the OrientDB command line.

The following statement is the basic syntax of the info command.

LIST DATABASES

Note − You can use this command only after connecting to a local or remote server.

Example

Before retrieving the list of databases, we have to connect to the localhost server through the remote server. It is required to remind that the username and password for connecting to the localhost instance is guest and guest respectively, which is configured in the orintdb/config/orientdb-server-config.xml file.

You can use the following command to connect to the localhost database server instance.

orientdb> connect remote:localhost guest

It will ask the password. As per the config file password for guest is also guest. If it is successfully connected, you will get the following output.

Connecting to remote Server instance [remote:localhost] with user ''guest''...OK
orientdb {server = remote:localhost/}>

After connecting to the localhost database server you can use the following command to list the databases.

orientdb {server = remote:localhost/}> list databases

If it is successfully executed, you will get the following output −

Found 6 databases:
* demo (plocal)
* s2 (plocal)
* s1 (plocal)
* GratefulDeadConcerts (plocal)
* s3 (plocal)
* sample (plocal)
orientdb {server = remote:localhost/}>

In this chapter, you can learn how to display the configuration of a particular database through OrientDB command line. This command is applicable for both local and remote databases.

Configuration information contains default cache either enabled or not, the size of that cache, the load factor value, max memory for map, node page size, pool minimum and maximum size, etc.

The following statement is the basic syntax of the config database command.

CONFIG

Note − You can use this command only after connecting to a particular database.

Example

In this example, we will use the same database named ‘demo’ that we created in the previous chapter.

You can use the following command to display the configuration of demo database.

Orientdb {db = demo}> CONFIG

If it is successfully executed, you will get the following output.

LOCAL SERVER CONFIGURATION:
+---------------------------------------+-------------------------+
| NAME                                  | VALUE                   |
+---------------------------------------+-------------------------+
| environment.dumpCfgAtStartup          | false                   |
| environment.concurrent                | true                    |
| environment.allowJVMShutdown          | true                    |
| script.pool.maxSize                   | 20                      |
| memory.useUnsafe                      | true                    |
| memory.directMemory.safeMode          | true                    |
| memory.directMemory.trackMode         | false                   |
|………………………………..                         |                         |
| storage.lowestFreeListBound           | 16                      |
| network.binary.debug                  | false                   |
| network.http.maxLength                | 1000000                 |
| network.http.charset                  | utf-8                   |
| network.http.jsonResponseError        | true                    |
| network.http.json                     | false                   |
| tx.log.fileType                       | classic                 |
| tx.log.synch                          | false                   |
| tx.autoRetry                          | 1                       |
| client.channel.minPool                | 1                       |
| storage.keepOpen                      | true                    |
| cache.local.enabled                   | true                    |
+---------------------------------------+-------------------------+
orientdb {db = demo}>

In the above list of configuration parameters, if you want to change any of the parameter value then you can do it from the command line easily using config set and get command.

Config Set

You can update the configuration variable value by using the CONFIG SET command.

The following statement is the basic syntax of the config set command.

CONFIG SET <config-variable> <config-value>

Note − You can use this command only after connecting to a particular database.

Example

In this example, we will use the same database named ‘demo’ that we created in the previous chapter. We will modify the ‘tx.autoRetry’ variable value to 5.

You can use the following command to set the configuration of demo database.

orientdb {db = demo}> CONFIG SET tx.autoRetry 5

If it is successfully executed, you will get the following output.

Local configuration value changed correctly

Config Get

You can display the configuration variable value by using the CONFIG GET command.

The following statement is the basic syntax of the config get command.

CONFIG GET <config-variable>

Note − You can use this command only after connecting to a particular database.

Example

In this example, we will use the same database named ‘demo’ that we created in the previous chapter. We will try to retrieve the ‘tx.autoRetry’ variable value.

You can use the following command to display the configuration of demo database.

orientdb {db = demo}> CONFIG GET tx.autoRetry

If it is successfully executed, you will get the following output.

Local configuration: tx.autoRetry = 5

The OrientDB Console is a Java Application made to work against OrientDB databases and Server instances. There are several console modes that OrientDB supports.

Interactive Mode

This is the default mode. Just launch the console by executing the following script bin/console.sh (or bin/console.bat in MS Windows systems). Make sure to have execution permission on it.

OrientDB console v.1.6.6 www.orientechnologies.com
Type ''help'' to display all the commands supported.

orientdb>

Once done, the console is ready to accept commands.

Batch Mode

To execute commands in batch mode run the following bin/console.sh (or bin/console.bat in MS Windows systems) script passing all the commands separated with semicolon “;”.

orientdb> console.bat "connect remote:localhost/demo;select * from profile"

Or call the console script passing the name of the file in text format containing the list of commands to execute. Commands must be separated with semicolon “;”.

Example

Command.txt contains the list of commands which you want to execute through OrientDB console. The following command accepts the batch of commands from the command.txt file.

orientdb> console.bat commands.txt

In batch mode, you can ignore errors to let the script continue the execution by setting the “ignoreErrors” variable to true.

orientdb> set ignoreErrors true

Enable Echo

When you run console commands in pipeline, you will need to display them. Enable “echo” of commands by setting it as property at the beginning. Following is the syntax to enable echo property in OrientDB console.

orientdb> set echo true

The main feature of OrientDB is to support multi-model objects, i.e. it supports different models like Document, Graph, Key/Value and Real Object. It contains a separate API to support all these four models.

Document Model

The terminology Document model belongs to NoSQL database. It means the data is stored in the Documents and the group of Documents are called as Collection. Technically, document means a set of key/value pairs or also referred to as fields or properties.

OrientDB uses the concepts such as classes, clusters, and link for storing, grouping, and analyzing the documents.

The following table illustrates the comparison between relational model, document model, and OrientDB document model −

Graph Model

A graph data structure is a data model that can store data in the form of Vertices (Nodes) interconnected by Edges (Arcs). The idea of OrientDB graph database came from property graph. The vertex and edge are the main artifacts of the Graph model. They contain the properties, which can make these appear similar to documents.

The following table shows a comparison between graph model, relational data model, and OrientDB graph model.

The Key/Value Model

The Key/Value model means that data can be stored in the form of key/value pair where the values can be of simple and complex types. It can support documents and graph elements as values.

The following table illustrates the comparison between relational model, key/value model, and OrientDB key/value model.

The Object Model

This model has been inherited by Object Oriented programming and supports Inheritance between types (sub-types extends the super-types), Polymorphism when you refer to a base class and Direct binding from/to Objects used in programming languages.

The following table illustrates the comparison between relational model, Object model, and OrientDB Object model.

Before go ahead in detail, it is better to know the basic terminology associated with OrientDB. Following are some of the important terminologies.

Record

The smallest unit that you can load from and store in the database. Records can be stored in four types.

• Document
• Record Bytes
• Vertex
• Edge

Record ID

When OrientDB generates a record, the database server automatically assigns a unit identifier to the record, called RecordID (RID). The RID looks like #<cluster>:<position>. <cluster> means cluster identification number and the <position> means absolute position of the record in the cluster.

Documents

The Document is the most flexible record type available in OrientDB. Documents are softly typed and are defined by schema classes with defined constraint, but you can also insert the document without any schema, i.e. it supports schema-less mode too.

Documents can be easily handled by export and import in JSON format. For example, take a look at the following JSON sample document. It defines the document details.

{
   "id"        : "1201",
   "name"      : "Jay",
   "job"       : "Developer",
   "creations" : [
      {
         "name"    : "Amiga",
         "company" : "Commodore Inc."
      },

      {
         "name"    : "Amiga 500",
         "company" : "Commodore Inc."
      }
   ]
}

RecordBytes

Record Type is the same as BLOB type in RDBMS. OrientDB can load and store document Record type along with binary data.

Vertex

OrientDB database is not only a Document database but also a Graph database. The new concepts such as Vertex and Edge are used to store the data in the form of graph. In graph databases, the most basic unit of data is node, which in OrientDB is called a vertex. The Vertex stores information for the database.

Edge

There is a separate record type called the Edge that connects one vertex to another. Edges are bidirectional and can only connect two vertices. There are two types of edges in OrientDB, one is regular and another one lightweight.

Class

The class is a type of data model and the concept drawn from the Object-oriented programming paradigm. Based on the traditional document database model, data is stored in the form of collection, while in the Relational database model data is stored in tables. OrientDB follows the Document API along with OPPS paradigm. As a concept, the class in OrientDB has the closest relationship with the table in relational databases, but (unlike tables) classes can be schema-less, schema-full or mixed. Classes can inherit from other classes, creating trees of classes. Each class has its own cluster or clusters, (created by default, if none are defined).

Cluster

Cluster is an important concept which is used to store records, documents, or vertices. In simple words, Cluster is a place where a group of records are stored. By default, OrientDB will create one cluster per class. All the records of a class are stored in the same cluster having the same name as the class. You can create up to 32,767(2^15-1) clusters in a database.

The CREATE class is a command used to create a cluster with specific name. Once the cluster is created you can use the cluster to save records by specifying the name during the creation of any data model.

Relationships

OrientDB supports two kinds of relationships: referenced and embedded. Referenced relationships means it stores direct link to the target objects of the relationships. Embedded relationships means it stores the relationship within the record that embeds it. This relationship is stronger than the reference relationship.

Database

The database is an interface to access the real storage. IT understands high-level concepts such as queries, schemas, metadata, indices, and so on. OrientDB also provides multiple database types. For more information on these types, see Database Types.