com.neurosys.odb.document.etl

Class ODBExecuteTransformer

java.lang.Object

com.neurosys.odb.document.etl.ODBExecuteTransformer

All Implemented Interfaces:

UpdatableContext<com.orientechnologies.orient.core.db.OPartitionedDatabasePool>, Serializable, org.apache.commons.collections.Transformer

public class ODBExecuteTransformer
extends Object
implements UpdatableContext<com.orientechnologies.orient.core.db.OPartitionedDatabasePool>, org.apache.commons.collections.Transformer, Serializable

Transformer : Orientdb Execute transformer : Fire any OrientDb DML query to manipulate records and classes of ODB database.

Input types to transformer : Transformer accepts inputs of type Object[] or Collection or through class member fieldMapping.

Any params supplied in the form of Collection will be converted to an Object[]. Any params supplied will be applied sequentially if the input is an Object[] or a List. If the input is not an Array or List BUT a "fieldMapping" is provided then map from query param name to field name or Transformer that will act on input to get param value

Structure of Prepared Queries :

In Orientdb, Prepared queries use two kinds of markers to substitute parameters on execution '?' syntax is used in reference to position parameters. For instance : OCommandSQL commandQuer = new OCommandSQL("UPDATE King SET kingdom = 'Winterfell' WHERE name = ?"); ':paramName' Syntax is used in reference to named parameters. For instance : OCommandSQL commandQuer = new OCommandSQL("UPDATE King SET kingdom = 'Winterfell' WHERE name = :kingName"); It is to be Noted that, ':paramName' consisting of only numerics or a combination consisting only of numerics and special characters are not supported (eg= ':1' or or ':?1'.

Functions to query from database :

ODatabaseDocument provides some methods to interact with the database via SQL statements and scripts. 'query()' method are intended to execute idempotent statements only (eg. SELECT, MATCH, TRAVERSE). 'command()' methods can execute any type of statements, idempotent (SELECT, MATCH...), non idempotent (INSERT, UPDATE, DELETE...) and DDL (CREATE CLASS, CREATE PROPERTY...) Link for Neurosys documentation on querying from database.

NOTE : We will be using command() in this transformer since database manipulation will be done through this transformer.

Reference Links related to Querying in Orientdb Java Querying API for Orientdb Pagination in Orientdb Prepared Queries in Orientdb Querying Documents Neurosys Documentation on Querying from database Neurosys docs on CRUD operations Refer to neurosys doc on OResultSet here

Author:

Nitin Sharma

See Also:

Transformer, UpdatableContext,

, Serialized Form