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ORM Basics
ORM Basics
Demo
Advanced Mapping
What happens internally
Transaction & concurrency control
Caching & optimization
Event Handling
Auto-generation of tables
Q & A

Object - Relational Mapping
Object - Relational Mapping
A persistence framework to map objects to the relational database without writing SQL.
A programming technique for converting data between incompatible type systems in relational databases and object-oriented programming languages.
ColdFusion ORM – based on Hibernate
One of the most mature and popular persistence framework

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Collection Mapping
Collection Mapping
Inheritance Mapping
Embedded Mapping
Join Mapping
Using Hibernate mapping files directly

Similar to 1:n relationship
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

Three Types
Three Types
Table per hierarchy

Three Types
Three Types
Table per hierarchy
Table per subclass

Three Types
Three Types
Table per hierarchy
Table per subclass
Table per subclass with discriminator

One entity with multiple CFC
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>

Useful when using one CFC for multiple tables
Useful when using one CFC for multiple tables
<cfcomponent persistent="true“ table=“Person”>
<cfproperty name="id">
<cfproperty name="name">
<cfproperty name="city"
            table="Address” joincolumn=“personId">
<cfproperty name="country"
            table="Address“ joincolumn=“personId"> </cfcomponent>

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Represents a unit of work – typically a transaction
Represents a unit of work – typically a transaction
All the ORM operations happen in a session
Provides First Level Caching
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

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Transient
Transient
Persistent
Detached

Optimistic lock for high concurrency
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.

Immediate fetching
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

Session Level
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
EntityReload re-fetches
Secondary Level Cache

Caches data across sessions
Caches data across sessions
In-memory/disk/clustered
Pluggable cache impls
Default - EHCache
Component Caching
Collection Caching
Query Caching

Configuration in Application.cfc
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">

Component
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"});

Read-only
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

ORMEvictEntity
ORMEvictEntity
ORMEvictEntity("<component_name>", [primarykey])
ORMEvictCollection
ORMEvictCollection("<component_name>", "<relation_name>",              [primarykey])
ORMEvictQueries
ORMEvictQueries([cachename])

Set ormsettings.eventhandling=“true”
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

Tables created on Application startup
Tables created on Application startup
ormsettings.dbcreate
Update – create new or update if table exists
Dropcreate – drop and then create table
None – do nothing
ormsettings.sqlscript
Executes the sql script at the time of table creation.

Defines the strategy for naming tables and columns
Defines the strategy for naming tables and columns
ormsettings.namingStrategy
Default – CFC/property name matches table/column name
Smart – camel cased name is uppercased with “_” between words.
CFC “OrderProduct” is “ORDER_PRODUCT”, OrderID is “ORDER_ID”
Your own CFC that implements cfide.orm.INamingStrategy
Component UCaseStrategy implements cfide.orm.INamingStrategy
{
public string function getTableName(string tableName)
{
return Ucase(tableName);
}
public string function getColumnName(string columnName)
{
return Ucase(columnName);
}
}

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