com.neurosys.odb.etl

Class ODBQueryTransformer<E,T>

java.lang.Object

com.neurosys.odb.etl.ODBQueryTransformer<E,T>

Type Parameters:

E - as input Entity

T - as return type

All Implemented Interfaces:

QueryTransformer, UpdatableContext<com.orientechnologies.orient.core.db.OPartitionedDatabasePool>, Serializable, Function<E,List<T>>, org.apache.commons.collections.Transformer

Direct Known Subclasses:

ODBQueryTransformer, ODBQueryTransformer

public abstract class ODBQueryTransformer<E,T>
extends Object
implements UpdatableContext<com.orientechnologies.orient.core.db.OPartitionedDatabasePool>, QueryTransformer, Function<E,List<T>>, Serializable

Author:

Arjun Dhar

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected com.orientechnologies.orient.core.db.OPartitionedDatabasePool	connectionPool Document database Connection Pool
protected boolean	expectSingleResult If true it will attempt to return only 1 Object or null if no match to query One should use the LIMIT keyword in query when setting this to true.
protected Map<String,?>	fieldMapping Map from query param name to field name or Transformer that will act on input to get param value.
protected com.orientechnologies.orient.core.db.ODatabase	lastConnection
protected boolean	paramAsSingleInput If true, will take whole input to transformer as a single parameter and pass it in query.
protected String	query Orientdb Query to process

Constructor Summary

Constructors

Constructor and Description
ODBQueryTransformer()
ODBQueryTransformer(ODBQueryTransformer t)
ODBQueryTransformer(String query, com.orientechnologies.orient.core.db.OPartitionedDatabasePool connectionPool)

Method Summary

Modifier and Type	Method and Description
List<T>	apply(E input)
void	close()
protected abstract com.orientechnologies.orient.core.db.ODatabase<T>	getConnection()
com.orientechnologies.orient.core.db.OPartitionedDatabasePool	getConnectionPool()
Map<String,?>	getFieldMapping() Map from query param name to field name or Transformer that will act on input to get param value.
String	getQuery() Query to process.
boolean	isExpectSingleResult() If true it will attempt to return only 1 Object or null if no match to query One should use the LIMIT keyword in query when setting this to true.
boolean	isParamAsSingleInput() If true, will take whole input to transformer as a single parameter and pass it in query.
void	setConnectionPool(com.orientechnologies.orient.core.db.OPartitionedDatabasePool connectionPool)
void	setExpectSingleResult(boolean expectSingleResult) If true it will attempt to return only 1 Object or null if no match to query One should use the LIMIT keyword in query when setting this to true.
void	setFieldMapping(Map<String,?> fieldMapping) Map from query param name to field name or Transformer that will act on input to get param value.
void	setParamAsSingleInput(boolean paramAsSingleInput) If true, will take whole input to transformer as a single parameter and pass it in query.
void	setQuery(String query) Query to process.
Object	transform(Object input) ODBQueryTransformer
void	updateContext(com.orientechnologies.orient.core.db.OPartitionedDatabasePool odbConnectionPool)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.function.Function

andThen, compose, identity

Field Detail

connectionPool

protected transient com.orientechnologies.orient.core.db.OPartitionedDatabasePool connectionPool

Document database Connection Pool

See Also:

ODatabasePool, OPartitionedDatabasePool

query

protected String query

Orientdb Query to process

expectSingleResult

protected boolean expectSingleResult

If true it will attempt to return only 1 Object or null if no match to query
One should use the LIMIT keyword in query when setting this to true.

paramAsSingleInput

protected boolean paramAsSingleInput

If true, will take whole input to transformer as a single parameter and pass it in query.

fieldMapping

protected Map<String,?> fieldMapping

Map from query param name to field name or Transformer that will act on input to get param value.

lastConnection

protected transient com.orientechnologies.orient.core.db.ODatabase lastConnection

Constructor Detail

ODBQueryTransformer

public ODBQueryTransformer()

ODBQueryTransformer

public ODBQueryTransformer(String query,
                           com.orientechnologies.orient.core.db.OPartitionedDatabasePool connectionPool)

Parameters:

query - : Query to be executed

connectionPool - : instance of Orientdb Connection pool ODatabasePool or OPartitionedDatabasePool

ODBQueryTransformer

public ODBQueryTransformer(ODBQueryTransformer t)

Method Detail

getConnection

protected abstract com.orientechnologies.orient.core.db.ODatabase<T> getConnection()

close

public void close()

transform

public Object transform(Object input)

ODBQueryTransformer

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. ':paramName' Syntax is used in reference to named parameters. It is to be Noted that, ':paramName' consisting of numerics or a combination 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...) Reference Link

Input Types :

Transformer accepts inputs of type Object[] or Collection or Map or PageInfo Any params supplied will be applied sequentially if the input is an Object[] or a List One can provide PageInfo as the input itself or last param in the parameter Array; if pagination is required One can provide a Map to this Transformer. When a Map is passed then Query parameters are the "Keys" passed in this Map. Any value thats associated as a PageInfo will be used to set the PageSize and other page related information to the Query. and in Query its parameter name will be same as dataMemberName of PageInfo class. For Eg : if PageInfo.recordNumber is to be used to set value in Query, then its parameter in Query will be ':recordNumber' and similarly for PageInfo.pageSize it will be 'pageSize' If the input is not an Array, List, Map or PageInfo 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

Specified by:

transform in interface org.apache.commons.collections.Transformer

Parameters:

input - : parameter of type `Object[]` or `Collection` or `Map` or `PageInfo`

Returns:

queried record documents

updateContext

public void updateContext(com.orientechnologies.orient.core.db.OPartitionedDatabasePool odbConnectionPool)

Specified by:

updateContext in interface UpdatableContext<com.orientechnologies.orient.core.db.OPartitionedDatabasePool>

getQuery

public String getQuery()

Description copied from interface: QueryTransformer

Query to process.

Specified by:

getQuery in interface QueryTransformer

Returns:

query

setQuery

public void setQuery(String query)

Description copied from interface: QueryTransformer

Query to process.

Specified by:

setQuery in interface QueryTransformer

isExpectSingleResult

public boolean isExpectSingleResult()

If true it will attempt to return only 1 Object or null if no match to query
One should use the LIMIT keyword in query when setting this to true.

Specified by:

isExpectSingleResult in interface QueryTransformer

Returns:

setExpectSingleResult

public void setExpectSingleResult(boolean expectSingleResult)

If true it will attempt to return only 1 Object or null if no match to query
One should use the LIMIT keyword in query when setting this to true.

Specified by:

setExpectSingleResult in interface QueryTransformer

isParamAsSingleInput

public boolean isParamAsSingleInput()

Description copied from interface: QueryTransformer

If true, will take whole input to transformer as a single parameter and pass it in query.

Specified by:

isParamAsSingleInput in interface QueryTransformer

Returns:

setParamAsSingleInput

public void setParamAsSingleInput(boolean paramAsSingleInput)

Description copied from interface: QueryTransformer

If true, will take whole input to transformer as a single parameter and pass it in query.

Specified by:

setParamAsSingleInput in interface QueryTransformer

getFieldMapping

public Map<String,?> getFieldMapping()

Description copied from interface: QueryTransformer

Map from query param name to field name or Transformer that will act on input to get param value.

Specified by:

getFieldMapping in interface QueryTransformer

Returns:

setFieldMapping

public void setFieldMapping(Map<String,?> fieldMapping)

Description copied from interface: QueryTransformer

Map from query param name to field name or Transformer that will act on input to get param value.

Specified by:

setFieldMapping in interface QueryTransformer

getConnectionPool

public com.orientechnologies.orient.core.db.OPartitionedDatabasePool getConnectionPool()

setConnectionPool

public void setConnectionPool(com.orientechnologies.orient.core.db.OPartitionedDatabasePool connectionPool)

apply

public List<T> apply(E input)

Specified by:

apply in interface Function<E,List<T>>