Property in OrientDB works like a field of class and column in the database table. Create Property is a command used to create a property for a particular class. The class name that you used in the command must exist.

The following statement is the basic syntax of Create Property command.

CREATE PROPERTY <class-name>.<property-name> <property-type> [<linked-type>][ <linked-class>]

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

<class-name> − Defines the class you want to create the property in.

<property-name> − Defines the logical name of the property.

<property-type> − Defines the type of property you want to create.

<linked-type> − Defines the container type, used in container property type.

<linked-class> − Defines the container class, used in container property type.

The following table provides the data type for property so that OrientDB knows the type of data to store.

In addition to these there are several other property types that work as containers.

Example

Try the following example to create a property name on the class Employee, of the String type.

orientdb> CREATE PROPERTY Employee.name STRING

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

Property created successfully with id = 1

Alter Cluster command is to update attributes on an existing cluster. In this chapter you can learn how to add or modify the attributes of a cluster.

The following statement is the basic syntax of Alter Cluster command.

ALTER CLUSTER <cluster> <attribute-name> <attribute-value>

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

<cluster> − Defines the cluster name.

<attribute-name> − Defines the attribute you want to change.

<attribute-value> − Defines the value you want to set for this attribute.

The following tabular format provides the list of supported attributes you can use along with Alter cluster command.

The following table provides the list of Conflict strategies.

Example

Try the following example queries to learn Alter cluster command.

Execute the following command to change the name of a cluster from Employee to Employee2.

orientdb {db = demo}> ALTER CLUSTER Employee NAME Employee2

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

Cluster updated successfully

Execute the following command to change the name of a cluster from Employee2 to Employee using cluster ID.

orientdb {db = demo}> ALTER CLUSTER 12 NAME Employee

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

Cluster updated successfully

Execute the following command to change the cluster conflict strategy to automerge.

orientdb {db = demo}> ALTER CLUSTER V CONFICTSTRATEGY automerge

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

Cluster updated successfully

The Drop Cluster command removes the cluster and all its related content. This operation is permanent and rollback.

The following statement is the basic syntax of Drop Cluster command.

DROP CLUSTER <cluster-name>|<cluster-id>

Where <cluster-name> defines the name of the cluster you want to remove and <cluster-id> defines the ID of the cluster you want to remove.

Example

Try the following command to remove Sales cluster.

orientdb> DROP CLUSTER Sales

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

Cluster dropped successfully

The Truncate Cluster command deletes all records of a cluster.

The following statement is the basic syntax of Truncate Cluster Command.

TRUNCATE CLUSTER <cluster-name>

Where <cluster-name> is the name of the cluster.

Example

Try the following query to truncate the cluster named sales.

Orientdb {db = demo}> TRUNCATE CLUSTER Profile

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

Cluster truncated successfully.

Cluster is an important concept in OrientDB 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, which has 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 a 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. If you want to add a new cluster to a class, use Alter Class command and ADDCLUSTER command.

The following statement is the basic syntax of Create Cluster command.

CREATE CLUSTER <cluster> [ID <cluster-id>]

Where <cluster> defines the name of the cluster you want to create and <cluster-id> defines the numeric ID you want to use for the cluster.

The following table provides the list of Cluster selection strategies.

Example

Let us take an example to create a cluster named sales.

orientdb> CREATE CLUSTER sales

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

Cluster created correctly with id #12

OrientDB is a NoSQL database that can store the documents and graph-oriented data. NoSQL database does not contain any table, so how can you insert data as a record. Here you can see the table data in the form of class, property, vertex, and edge meaning classes are like tables, and properties are like files in the tables.

We can define all these entities using schema in OrientDB. Property data can be inserted into a class. Insert command creates a new record in the database schema. Records can be schema-less or follow some specified rules.

The following statement is the basic syntax of the Insert Record command.

INSERT INTO [class:]<class>|cluster:<cluster>|index:<index>
   [(<field>[,]*) VALUES (<expression>[,]*)[,]*]|
   [SET <field> = <expression>|<sub-command>[,]*]|
   [CONTENT {<JSON>}]
   [RETURN <expression>]
   [FROM <query>]

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

SET − Defines each field along with the value.

CONTENT − Defines JSON data to set field values. This is optional.

RETURN − Defines the expression to return instead of number of records inserted. The most common use cases are −

• @rid − Returns the Record ID of the new record.

• @this − Returns the entire new record.

FROM − Where you want to insert the record or a result set.

Example

Let us consider a Customer table with the following fields and types.

You can create the Schema (table) by executing the following commands.

CREATE DATABASE PLOCAL:/opt/orientdb/databases/sales
CREATE CLASS Customer
CREATE PROPERTY Customer.id integer
CREATE PROPERTY Customer.name String
CREATE PROPERTY Customer.age integer

After executing all the commands, you will get the table name Customer with id, name, and age fields. You can check the table by executing select query into the Customer table.

OrientDB provides different ways to insert a record. Consider the following Customer table containing the sample records.

The following command is to insert the first record into the Customer table.

INSERT INTO Customer (id, name, age) VALUES (01,''satish'', 25)

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

Inserted record ''Customer#11:0{id:1,name:satish,age:25} v1'' in 0.069000 sec(s).

The following command is to insert the second record into the Customer table.

INSERT INTO Customer SET id = 02, name = ''krishna'', age = 26

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

Inserted record ''Customer#11:1{id:2,age:26,name:krishna} v1'' in 0.005000 sec(s).

The following command is to insert the third record into the Customer table.

INSERT INTO Customer CONTENT {"id": "03", "name": "kiran", "age": "29"}

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

Inserted record ''Customer#11:2{id:3,name:kiran,age:29} v1'' in 0.004000 sec(s).

The following command is to insert the next two records into the Customer table.

INSERT INTO Customer (id, name, age) VALUES (04,''javeed'', 21), (05,''raja'', 29)

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

Inserted record ''[Customer#11:3{id:4,name:javeed,age:21} v1,
Customer#11:4{id:5,name:raja,age:29} v1]'' in 0.007000 sec(s).

You can check if all these records are inserted or not by executing the following command.

SELECT FROM Customer

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

----+-----+--------+----+-------+----
#   |@RID |@CLASS  |id  |name   |age
----+-----+--------+----+-------+----
0   |#11:0|Customer|1   |satish |25
1   |#11:1|Customer|2   |krishna|26
2   |#11:2|Customer|3   |kiran  |29
3   |#11:3|Customer|4   |javeed |21
4   |#11:4|Customer|5   |raja   |29
----+-----+--------+----+-------+----

Alter Property is a command used to modify or update the Property of a particular class. Altering the property means modifying the fields of a table. In this chapter, you can learn how to update the property.

The following statement is the basic syntax of Alter Property Command.

ALTER PROPERTY <class>.<property> <attribute-name> <attribute-value>

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

<class> − Defines the class to which the property belongs.

<property> − Defines the property you want to update.

<attribute-name> − Defines the attribute of a property you want to update.

<attribute-value> − Defines the value you want to set on the attribute.

The following table defines the list of attributes to alter the property.

Note − if you are altering NAME or TYPE, this command will take some time to update depending on the amount of data.

Example

Try some queries which are given below to understand Alter property.

Execute the following query to change the name of the property from ‘age’ to ‘born’ in the class Customer.

orinetdb {db = demo}> ALTER PROPERTY Customer.age NAME born

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

Property altered successfully

Execute the following query to make ‘name’ as the mandatory property of the class ‘Customer’.

orientdb {db = demo}> ALTER PROPERTY Customer.name MANDATORY TRUE

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

Property altered successfully

Export Record is the command used to export the loaded record into the requested and supported format. If you are executing any wrong syntax, it will give the list of supported formats. OrientDB is a family of Document database, therefore JSON is the default supported format.

The following statement is the basic syntax of the Export Record command.

EXPORT RECORD <format>

Where <Format> defines the format you want to get the record.

Note − Export command will export the loaded record based on Record ID.

Example

Let us consider the same Customer table that we have used in the previous chapter.

Try the following query to retrieve the record having Record ID @rid: #11:0.

orientdb {db = demo}> LOAD RECORD #11:0

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

+---------------------------------------------------------------------------+
| Document - @class: Customer        @rid: #11:0           @version: 1      |
+---------------------------------------------------------------------------+
|                     Name | Value                                          |
+---------------------------------------------------------------------------+
|                       id | 1                                              |
|                     name | satish                                         |
|                      age | 25                                             |
+---------------------------------------------------------------------------+

Use the following query to export he loaded record (#11:0) into JSON format.

orientdb {db = demo}> EXPORT RECORD json

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

{
   "@type": "d",
      "@rid": "#11:0",
   "@version": 1,
   "@class": "Customer",
      "id": 1,
      "name": "satish",
      "age": 25
}

Load Record is used to load a particular record from the schema. Load record will load the record with the help of Record ID. It is represented with @rid symbol in the resultset.

The following statement is the basic syntax of the LOAD Record command.

LOAD RECORD <record-id>

Where <record-id> defines the record id of the record you want to load.

If you don’t know the Record ID of a particular record, then you can execute any query against the table. In the result-set you will find the Record ID (@rid) of the respective record.

Example

Let us consider the same Customer table that we have used in previous chapters.

Try the following query to retrieve the record having Record ID @rid: #11:0.

orientdb {db = demo}> LOAD RECORD #11:0

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

+---------------------------------------------------------------------------+
| Document - @class: Customer        @rid: #11:0           @version: 1      |
+---------------------------------------------------------------------------+
|                     Name | Value                                          |
+---------------------------------------------------------------------------+
|                       id | 1                                              |
|                     name | satish                                         |
|                      age | 25                                             |
+---------------------------------------------------------------------------+

Reload Record also works similar to Load Record command and is also used to load a particular record from the schema. Load record will load the record with the help of Record ID. It is represented with @rid symbol in the result-set. The main difference is Reload record ignores the cache which is useful when external concurrent transactions is applied to change the record. It will give the latest update.

The following statement is the basic syntax of the RELOAD Record command.

RELOAD RECORD <record-id>

Where <record-id> defines the record id of the record you want to reload.

If you don’t know the Record ID of a particular record, then you can execute any query against the table. In the result-set you will find the Record ID (@rid) of the respective record.

Example

Let us consider the same Customer table that we have used in the previous chapter.

Try the following query to retrieve the record having Record ID @rid: #11:0.

orientdb {db = demo}> LOAD RECORD #11:0

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

+---------------------------------------------------------------------------+
| Document - @class: Customer        @rid: #11:0           @version: 1      |
+---------------------------------------------------------------------------+
|                     Name | Value                                          |
+---------------------------------------------------------------------------+
|                       id | 1                                              |
|                     name | satish                                         |
|                      age | 25                                             |
+---------------------------------------------------------------------------+