coldfusion orm - part ii

Copyright 2009 Adobe Systems Incorporated. All rights reserved. Adobe confidential. 1

ColdFusion-ORM - II

Rupesh Kumar

Sr. Computer Scientist

Blog: www.rupeshk.org

http://www.rupeshk.org/

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Agenda

Relationships (contd from last session)

Application settings

Advanced Mapping

What happens internally

Transaction & concurrency control

Caching & optimization

Event Handling

Q & A

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Address.cfc

<cfproperty name="EmployeeObj" fieldtype="one-to-one" cfc="employees"

fkcolumn="EmployeeID">

Employees.cfc

<cfproperty name="addressObj" fieldtype="one-to-one" cfc="address"

mappedby="EmployeeObj">

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Mapping One-to-One relationship

EMPLOYEES

EmployeeID(PK)

LastName

FirstName

Title

ADDRESSES

AddressID(PK)

HouseNumber

Street

City

State

Country

EmployeeID

1

1

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EMPLOYEES

EmployeeID(PK)

LastName

FirstName

Title

Mapping Many-to-Many relationship

<cfproperty name=“Territories” fieldtype=“many-to-many” cfc=“territories”

linktable=“employeeterritories” fkcolumn=“EmployeeID”

inversejoincolumn=“TerritoryID”>

TERRITORIES

TerritoryID(PK)

TerritoryDescription

n n

EMPLOYEETERRITORIES

EmployeeID(PK)

TerritoryID(PK)


ColdFusion-ORM

APPLICATION

SETTINGS

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Ormenabled – Specifies whether ORM should be used for the

ColdFusion application

Eg: <cfset this.ormenabled = true>

ORMSettings – The struct that defines all the ORM settings

Eg: <cfset this.ormsettings = {datasource=“employees”}>

datasource – Defines the default datasource for the

application.

Eg: <cfset this.datasource = “employees” >

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Application Level Settings

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cfclocation – Specifies the directory (or array of directories) to

search for persistent CFCs.

Eg: <cfset this.ormsettings = {cfclocation=“/empSys/model/”}>

savemapping – Specifies whether the generated Hibernate

mapping file has to be saved to disk.

Eg: <cfset this.ormsettings = {savemapping=“true”}>

logSQL – Specifies whether the SQL queries that are executed

by ORM will be logged.

Eg: <cfset this.ormsettings = {logSQL=“true”}>

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Application Level Settings – ormsettings

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datasource– Specifies the datasource to be used by ORM.

Eg: <cfset this.ormsettings = {datasource=“employees”}>

secondaryCacheEnabled – Specifies whether the secondary

cache will be enabled for ORM.

Eg: <cfset this.ormsettings = {secondarycacheEnabled=“true”}>

eventHandling – Specifies whether the event handling is

enabled for ORM.

Eg: <cfset this.ormsettings = {eventHandling=“true”}>

Many More…88

Application Level Settings – ormsettings

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dbCreate – Specifies whether tables should be auto-generated at

application startup.

Update – create new or update if table exists

Dropcreate – drop and then create table

None* – do nothing

NamingStrategy – Specifies the method used to generate the

table/column names.

Default* – CFC names matches table/column name

Smart – CFC “OrderProduct” is “ORDER_PRODUCT” in db

Your own CFC – implements cfide.orm.INamingStrategy

SqlScript – Specifies the sql script file that will be run after the

tables are created. It can be used to initialize the DB.

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Ormsettings for Auto-generating tables

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Advanced Mapping

Collection Mapping

Embedded Mapping

Inheritance Mapping

Join Mapping

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Collection Mapping

Similar to 1:n relationship

Useful when target table need not be mapped as persistent CFC

Just need information from the target table

Mapping defined similar to 1:n relationship

Demo

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Embedded Mapping

One entity with multiple CFC

A cfproperty refers to another cfc

Mapping needs to be specified in *.hbm.xml

<hibernate-mapping>

<class name="cfc:Employees" entity-name="employee"

table="Employees">

<id name="ID" type="integer" column="EmployeeID">

<generator class="native"/>

</id>

<component name="Name" class="cfc:cname">

<property name="FirstName" type="string" column="FirstName"/>

<property name="LastName" type="string" column="LastName"/>

</component>

<property name="Title" type="string" column="Title"/>

<property name="BirthDate" type="date" column="BirthDate"/>

<property name="HireDate" type="date" column="HireDate"/>

</class>

</hibernate-mapping>

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Inheritance Mapping

Three Types

Table per hierarchy

Payment

+ID

+Amount

+Date

CreditCardPayme

nt

+CardNo

+CardType

ChequePayment

+ChequeNo

+bankName

+City

ID <<PK>>

Amount

Date

PaymentType

(discriminator)

CardNo

CardType

ChequeNo

BankName

City

Payment Table

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Inheritance Mapping

Three Types

Table per hierarchy

Table per subclass without discriminator

Payment

+ID

+Amount

+Date

CreditCardPayme

nt

+CardNo

+CardType

ChequePayment

+ChequeNo

+bankName

+City

ID <<PK>>

Amount

Date

Payment Table

PaymentID

CardNo

CardType

CreidtCardPayment Table

PaymentId

ChequeNo

BankName

City

Cheque Payment Table

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Inheritance Mapping

Three Types

Table per hierarchy

Table per subclass without discriminator

Table per subclass with discriminator

Payment

+ID

+Amount

+Date

CreditCardPayme

nt

+CardNo

+CardType

ChequePayment

+ChequeNo

+bankName

+City

ID <<PK>>

Amount

Date

PaymentType

(discriminator)

Payment Table

PaymentID

CardNo

CardType

CreidtCardPayment Table

PaymentId

ChequeNo

BankName

City

Cheque Payment Table

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Join Mapping

Useful when using one CFC for multiple tables

<cfcomponent persistent="true“ table=“employee”>

<cfproperty name="id">

<cfproperty name="name">

<cfproperty name="city"

table="Address” joincolumn="addressId">

<cfproperty name="country"

table="Address“ joincolumn="addressId">

</cfcomponent>

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Application

Start

ORM

Enable

d?

Proceed

with other

activities

false

true

Create/Load

Hibernate

configuration if

specified

Load Hibernate

mapping files

(*.hbmxml)

Search for persistent

CFCs

Generate Hibernate

Mapping for

persistent CFCsDatabaseInspect

Generate DDL

based on dbcreate

Build Hibernate

Session Factory

Proceed

with other

activities

ORM Initialization

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ORM Session

Represents a unit of work – typically a transaction

All the ORM operations happen in a session

Ensures a single instance of an entity.

Tracks changes made to the objects

SQLs are executed when session is flushed

Typically when the transaction is committed or when the request completes

Can use ORMFlush to force

Automatically managed by CF

In most cases, you don’t need to worry about it

Provides First Level Caching

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ORM Session Management

New Request

New ORM Session

Call ORMFlush

Close Session

Batch all the operations

Application

Start

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ORM Session Management – Transactions

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New Request

New ORM Session

Application

Start

Call ORMFlush

Close ORM Session

New ORM Session

Call ORMFlush

Close ORM Session

Batch all the operations

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Object States

Transient

Persistent

Detached

EntityNew()/ new()/

CreateObject

Transient Entity

Persistent Entities

EntitySave()

DB

Detached

Session ends

EntityLoad

ORMExecuteQuery

EnityMerge

EntityDelete

EntitySave

Session

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Concurrency Control

Optimistic lock for high concurrency

Update only if the entity is not modified by other thread or externally.

optimisticlock attribute on cfc

All

All properties are included in where clause of update

Update myTbl set col1= newVal, col2= newVal2

where col1= oldVal and col2= oldVal2

Dirty

Includes only modified fields in the current session

Version (default)

Checks only version or timestamp column

<cfproperty name="lastModified“ fieldtype="timestamp|version“>

None

You can also choose the property for dirty check.

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Fetching Strategy

Immediate fetching

Fetch target relationship in a separate SQL, immediately

<cfproperty name=“emp" fieldtype="one-to-many" cfc=“order"

fkcolumn=“EMPID“ lazy="false" fetch="select">

Lazy fetching

Default strategy, lazy=true

On demand, fetch related entities

Lazy = “extra” gets pk of orders and then all order columns from db

Eager fetching

Fetch together in a single SQL, fetch=“join”

Useful for 1:1 frequently used relationships

Batch fetching

When fetching relationship, get some more that maybe required later

Get Addr1 for emp101, plus address for emp102, 103 etc from the table depending on

batch size

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Caching

Session Level

Ensures a single instance for a given ID

EntityLoad fetches data for the first time

Data is cached for the session

Next request in the same session will use cached data

EntyReload re-fetches

Secondary Level Cache

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Secondary Level Cache

Caches data across sessions

In-memory/disk/clustered

Pluggable cache impls

Default - EHCache

Component Caching

Collection Caching

Query Caching

Secondary Cache

…

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Secondary Level caching ...

Configuration in Application.cfc

ormsettings.secondarycacheenabled

ormsettings.Cacheprovider

JBossCache, OSCache, SwarmCache, Hashtable, DEFAULT - ehcache

ormsettings.cacheconfig

Appropriate config file for cache, e.g. ehcache.xml

In ORM cfc

“cacheuse” defines caching strategy

“cahcename” cache region, a bucket for this data

<cfcomponent persistent="true“

cachename=“foo_region" cacheuse="read-only">

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Caching - examples

Component

<cfcomponent persistent="true“

cachename=“foo_region" cacheuse="read-only">

Relationship

Primary Key of the associated object is cached

The associated object itself is cached if coded as above

<cfproperty name="arts" fieldtype="one-to-many“

cachename="foo_region" cacheuse="read-write">

Query data

ORMExecuteQuery("from Art where issold=0", {}, false,

{cacheable=true, cachename=“foo_region"});

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Caching – cacheuse

Read-only

Best performance for read only data

Nonrestrict-read-write

Use when data is updated occasionally

Read-write

Use if your data needs to be updated

More overhead than the two preceding strategies

Transactional

Transactional cache

Can only be used if the cache provider is transaction aware

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Caching - cleanup

ORMEvictEntity

ORMEvictEntity("<component_name>", [primarykey])

ORMEvictCollection

ORMEvictCollection("<component_name>", "<relation_name>",

[primarykey])

ORMEvictQueries

ORMEvictQueries([cachename])

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Event Handling

Set ormsettings.eventhandling=“true”

CFC level

preinsert and postinsert

predelete and postdelete

preupdate and postupdate

preload and postload

Application Level

Set ormsettings.eventhandler=“AppEventHandler.cfc”

Should implement the CFIDE.orm.IEventHandler interface


Q & A


Thank You !

- [email protected]

- http://www.rupeshk.org

mailto:[email protected]

http://www.rupeshk.org/

coldfusion orm - part ii

Technology

adobe confidential

adobe systems incorporated

orm settingseg

default datasource

cfc names

mapping file

application startup

sql script file