Bloggers in ColdFusion Product Team
During CFUG presentations, many people had asked me to post a list of bloggers in ColdFusion Product Team. I am sure most of them already are following a few of the blogs. Here is the current list:
Adam Lehman: http://www.adrocknaphobia.com/
Bhakti Pingale: http://ajaxforyou.blogspot.com/
Ben Forta: www.forta.com
Jayesh Viradiya: http://askjayvir.blogspot.com/
Josh Adams: http://blog.joshuaadams.com/
Kristen Schofield: http://www.webbschofield.com/
Manjukiran Pacchhipulusu: www.manjukiran.net
Rakshith: http://www.rakshith.net/
Rupesh Kumar: http://www.rupeshk.org
Sagar Ganatra: http://sagarganatra.blog.com/
Sandeep Paliwal: http://sandeepp.org/blog/
Sankaram Tata: http://sankaramt.wordpress.com/
Terrance Ryan: http://www.terrenceryan.com/blog/
Enjoy!!
ColdFusion-ORM: Define One-to-Many and Many-to-one relationships
Task:
Example to demonstrate how to establish one-to-many and many-to-one Relationships in ColdFusion-ORM
Previous Related Posts:
Getting Started with ORM
ColdFusion-ORM: Using CRUD Functions
Stuff that you would learn:
- how to establish a One-to-Many relationship between 2 CFCs.
- how to establish a Many-to-One relationship between 2 CFCs.
- how to do CRUD operations with CFCs which have a relationship.
- how to use the implicit relationship methods added by ColdFusion.
- cascade insert and delete
Steps to Run the example:
- This example needs the cfartgallery datasource. This is shipped with ColdFusion by default.
- Create a directory say "1tonorm" under webroot.
- Create the following files – Application.cfc, Art.cfc, Artists.cfc and index.cfm.
- Run the URL http://localhost:8500/1tonorm/index.cfm
I have interspersed the example with a lot of comments. You can understand the concept by just following the comments starting with Application.cfc and then Artists.cfc and then Arts.cfc and then index.cfm.
Application.cfc
component
{
//Name of the application
this.name = "ORM_One2Many";
//ormenabled should be set to true so that ORM is enabled for this application
this.ormenabled = "true";
//Set the datasource that needs to be used by the ORM Functions.
this.datasource = "cfartgallery";
}
Artists.cfc
component persistent="true"
{
property name="artistid" generator="increment";
property firstname;
property lastname;
property address;
property city;
property state;
property postalcode;
property email;
property phone;
property fax;
property thepassword;
/*
Artists have many arts and henace they form a one-to-many relation. The idea is to have all
the arts as an array of art objects in each Artists' object.
Set fieldytpe="one-to-many".
Specify CFC="Art" to convey that the relationship is with Art.cfc.
fkcolumn="artistid" to specify the foreign key. But this is not required if foreignkey constraint
is defined in the database - ColdFusion-ORM will figure it out by inspecting the database.
cascade="all-delete-orphan": "all" signifies that all the CRUD operations will be cascaded to the
related objects. "delete-orphan" means that it will delete the orphan objects in the art array
i.e. if i remove an art from the arts array, it is now an orphan as it has no artist associated
with it and hence will be automatically deleted.
Implit Methods: When a one-to-many relationship is established, the following implicit methods are introduced
into the artist object:
void addart(<artobj>) - used to add a art object to the relationship.
boolean removeart(<artobj>) - used to remove the art object from the relationship.
boolean hasart() - to check if there are any art objects in the artist object.
boolean hasart(<artobj>) - to check if the input art object is present in the artist object.
singularname: Use this attribute to specify custom name to the above implicit methods.
type=array: To retrieve the arts objects as an array. If type="struct", then the arts objects are retrieved as
key-value pairs. structkeycolumn and structkeytype should be specified in addition to all the above attributes
to retrieve arts as key-value pairs.
inverse=true: In a bi-directional relationship like this, you should specify one of the side as the controlling side
which will set the relationship. Usually, in a one-to-many bi-directional relationship, the many-to-one side should
be the controlling side. To do that, set inverse=true on this side (one-to-many side).
*/
property name="arts" type="array" fieldtype="one-to-many" cfc="Art" singularname="art" fkcolumn="artistid"
inverse="true" cascade="all-delete-orphan";
}
Art.cfc
component persistent="true"
{
property name="artid" generator="increment";
property name="artname";
property name="price";
property name="largeimage";
property name="mediaid";
property name="issold";
/*
Many arts have an artist and hence form a "many-to-one" relation.
To establish a "many-to-one" relation, set fieldytpe="many-to-one"
Specify CFC="Artists" to convey that the relationship is with Artists.cfc.
fkcolumn="artistid": Used to specify the foreign key.
missingRowIgnored: If the value is true, and the row that is referenced by the foreign
key is missing, it is treated as a null association.
*/
property name="artist" fieldtype="many-to-one" fkcolumn="artistid"
cfc="Artists" missingRowIgnored="true";
}
index.cfm
<!---
This example will teach you
- how to establish a One-to-Many relationship between 2 CFCs.
- how to establish a Many-to-One relationship between 2 CFCs.
- how to do CRUD operations with CFCs which have a relationship.
- how to use the implicit relationship methods added by ColdFusion.
- Using cascade in one-to-many to many-to-one relationships.
cfartgallery datasource is used for this application.
--->
<cfscript>
ormreload();
/*
Display the existing records in Artists Table.
This will display the artist and their arts.
*/
WriteOutput("<b>Initial state of the Artists and Art tables<br></b>");
DisplayArtists();
/*
Create an artist object and 2 art objects
*/
newArtist = new Artists();
newArtist.setfirstname("Daniel");
newArtist.setlastname("Richard");
newArt1 = new Art();
newArt1.setArtName("Champions");
newArt2 = new Art();
newArt2.setArtName("Isolate");
/*
Associate the Arts to the Artist. Notice that the
implicit-relationship method - addArt is called.
*/
newArtist.addArt(newArt1);
newartist.addArt(newArt2);
/*
The one-to-many relationship should be established from both
the ends. Hence set the Artist to the new Arts.
*/
newArt1.setArtist(newArtist);
newArt2.setArtist(newArtist);
/*
Save the new artist. Note that EntitySave will save the artist as
well as the associated arts as well (cascade-insert)
*/
EntitySave(newArtist);
ormflush();
/*
Display the existing records to check whether insert succeeded.
*/
WriteOutput("<b>State of the Artists and Art tables after insert. Notice that the new
artist - Daniel Richard is added with his arts 'Champions' and 'Isolate'<br></b>");
DisplayArtists();
/*
Remove newArt2 and add newArt3. In a way, you are just modifying the 'arts' array. Notice that
we are using the implicit=relationship method - removeArt is called.
*/
newArt3 = new Art();
newArt3.setArtName("Holiday");
newArt3.setArtist(newArtist);
newArtist.addArt(newArt3);
newArtist.removeArt(newArt2);
ormflush();
/*
Check if delete and update of art succeeded.
*/
WriteOutput("<b>State of the Artists and Art tables after Deleting/Updating his Arts. Notice that
the art 'Isolate' is removed and the art 'Holiday' is added.<br></b>");
DisplayArtists();
/*
Delete the Artist. Note that EntityDelete will delete
the Artist as well as the associated arts. (cascade-delete).
*/
EntityDelete(newArtist);
ormflush();
/*
Check if delete succeeded.
*/
WriteOutput("<b>State of the Artists and Art tables after deleting the Artist.
Notice that the artist 'Daniel Richard' is deleted. All his arts are also deleted!<br></b>");
DisplayArtists();
/*
A Utility function to display artists and his arts
*/
function DisplayArtists()
{
query1 = new Query();
query1.setSQL("select ArtistID, firstname, lastname from Artists where ArtistID>10");
WriteDump(query1.execute().getresult());
query1.setSQL("select ArtID, ArtName, ArtistID from Art where ArtID>50");
WriteDump(query1.execute().getresult());
}
</cfscript>
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