ColdFusion-ORM: Using CRUD Functions
Previous Related Posts:
Getting Started with ORM
First of all, pardon me for posting this example – I could have easily clubbed these concepts with my first post: Getting Started with ORM. I promise that in my further posts, I will club more concepts into a single example (but still try to keep it simple).
Task:
Example that demonstrates the CRUD Functions in ColdFusion-ORM
Stuff that you would learn:
- To work with the CRUD Functions – EntityNew, EntityLoad, EntitySave, EntityDelete
- ormflush() function to force-commit ORM calls
- OrmExecuteQuery function to execute HQL
- Saving the mapping file
Steps to Run the example:
- This example needs the cfartgallery datasource. This is shipped with ColdFusion by default.
- Create a directory say “crudorm” under webroot.
- Create the following files – Application.cfc, CArtists.cfc and index.cfm.
- Run the URL http://localhost:8500/crudorm/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 CArtists.cfc and then index.cfm.
Application.cfc
component
{
//Name of the application
this.name = "ORM_CRUDExample";
//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. You can also set this in the ormsettings struct
this.datasource = "cfartgallery";
/*
ColdFusion-ORM uses hibernate as its under-lying engine. ColdFusion-ORM generates
the hbm.xml file which contains the hibernate mapping. To save the hibernate mapping
that is generated, you need to set savemapping flag to true. In this case, CArtists.hbm.xml
file will be generated in the same folder as that of the application.
*/
this.ormsettings.savemapping="true";
}
CArtists.cfc
(I have not added any comments to this file. If you need to learn about the different attributes used here, refer the example Getting Started with ORM)
component persistent="true" entityname="Artists" table="Artists"
{
property name="id" column="ARTISTID" generator="increment";
property name="firstname";
property name="lastname";
property name="address";
property name="city";
property name="state";
property name="postalcode";
property name="email";
property name="phone";
property name="fax";
property name="thepassword";
}
index.cfm
<!---
This example will teach you
- how to do CRUD operations on this table using the Entity* functions.
- ormflush function.
- how to use ORMExecuteQuery function.
- Saving the mapping file
cfartgallery datasource is used for this application.
Artists table is one of the table in cfartgallery which contains a list of
artists records. This table is used in this example.
--->
<cfscript>
ormreload();
/*
Load the Artist records to display them. There are a number of
variations to the EntityLoad method which will help you to retrieve
the records the way you want. Refer the documentation for EntityLoad for details.
*/
WriteOutput("<b>Initial state of the table<br /></b>");
DisplayArtists(EntityLoad("Artists"));
/*
Create a new Artist object and set the properties. This will
be inserted to the table in the next step.
EntityNew function takes entityname as input and creates a
fresh object of the entity.
*/
newArtistObj = EntityNew("Artists");
newArtistObj.setfirstname("John");
newArtistObj.setlastname("Smith");
newArtistObj.setaddress("5 Newport lane");
newArtistObj.setcity("San Francisco");
newArtistObj.setstate("CA");
newArtistObj.setPostalCode("90012");
newArtistObj.setphone("612-832-2343");
newArtistObj.setfax("612-832-2344");
newArtistObj.setemail("jsmith@company.com");
newArtistObj.setThePassword("jsmith");
/*
Insert the new artist object that you just created.
EntitySave will insert the newArtistObj into the database.
EntitySave is used for both update and insert. ColdFusion
will smartly figure out whether it is an update or insert. As we are
sure that this is an insert operation, we set the secondparameter to "true".
ColdFusion now will always do the insert operation.
*/
EntitySave(newArtistObj, true);
/*
Call ormflush so that the Insert SQL runs immediately. If ormflush
is not called, all the CRUD operations in this page will be flushed at
the end of the request.
*/
ormflush();
/*
Display the artist records now to check if the new record got added.
This time I have used a different function to retrieve the Artist records.
This is just to introduce you to the ORMExecuteQuery set of functions.
ORMExecuteQuery takes HQL as input and returns one-entity/array-of-entities/
string/array-of-strings depending on the HQL. HQL is the query language used
in hibernate to retrieve objects based on complex joins. This function has
a number of overloads. Please refer the documentation for more details.
*/
WriteOutput("<b>After adding the new record (Notice the Record with FirstName John being added)<br /></b>");
DisplayArtists(ORMExecuteQuery("from Artists"));
/*
Update the new Artist record. Change the Phone number.
You dont need to call EntitySave method here as the newArtistObj is
an entity maintained by ORM. Hence the updates to this entity will be automatically committed.
*/
newArtistObj.setphone("612-832-1111");
ormflush();
/*
Display the Artist records now to check if the new record got updated.
*/
WriteOutput("<b>After updating the new record (Notice the phone number with FirstName John updated)<br /></b>");
DisplayArtists(ORMExecuteQuery("from Artists"));
/*
Delete the record. Also call ormflush so that the Delete SQL gets run immediately
*/
EntityDelete(newArtistObj);
ormflush();
/*
Display the Artist records now to check if the new record that was added, got deleted
*/
WriteOutput("<b>After deleting the new record (Notice the Record with FirstName John deleted)<br /></b>");
DisplayArtists(ORMExecuteQuery("from Artists"));
</cfscript>
<!---A simple function to display the artist records in a table--->
<cffunction name="DisplayArtists">
<cfargument name="artistArr">
<cfoutput>
<table border="1">
<tr>
<td>ID</td>
<td>NAME</td>
<td>ADDRESS</td>
<td>PHONE</td>
<td>FAX</td>
<td>EMAIL</td>
</tr>
<cfloop array="#artistArr#" index="artistsObj">
<tr>
<td>#artistsObj.getid()#</td>
<td>#artistsObj.getfirstname()# #artistsObj.getlastname()#</td>
<td>#artistsObj.getaddress()# #artistsObj.getCity()# #artistsObj.getState()# #artistsObj.getPostalCode()#</td>
<td>#artistsObj.getphone()#</td>
<td>#artistsObj.getFax()#</td>
<td>#artistsObj.getemail()#</td>
</tr>
</cfloop>
</table>
</cfoutput>
</cffunction>



Comments
Manju, thanks for putting these posts together.
I have a question on updates for multiple simultaneous requests. Can you explain what happens when multiple requests access the same record/object at the same time?
For example:
Request 1 reads a record
Request 2 reads a record
Request 1 updates the phone number of the record.
Request 2 access the phone number of the record
What phone number does request 2 see at this point? Does it see the original value stored in the database or the new value just set by request 1 (before the request ends).
Thanks, and I look forward to your next post!
Hi Manju,
I Look forward to more articles. I think Kevan has a very good question and am subscribing to the comments. In a nutshell, how does ColdFusion ORM handle conflict resolution for concurrent read/write?
Hi Kevan and Steve, ColdFusion-ORM is designed to handle concurrency and conflict resolution:
1. ColdFusion-ORM can be used with the cftransaction tag along with different isolationlevels (”read_uncommitted | read_committed | repeatable_read”). They work the same way as they do for cfquery stuff. See the ColdFusion 8 livedocs for an explanation of the different isolation levels.
2. Versioning properties can be defined for every persistent component which is one more way to handle conflict resolution and concurrency.
3. The attribute “optimistic-lock” can be defined in the persistent component with value that can be set to all or dirty or version or none.
For a detailed explanation on Versioning and optimistic-lock please refer “Versioning” and “Transaction and Concurrency” topics in ColdFusion documentation -> “Developing Applications with Adobe ColdFusion 9.pdf->Chapter 8: ColdFusion ORM”
Wow…these tutorials are awesome! I will be back.
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