CLI Overview
Quick Start Guide
wheels info
wheels reload
wheels deps
wheels destroy
wheels watch
wheels generate app
wheels generate app-wizard
wheels generate controller
wheels generate model
wheels generate view
wheels generate property
wheels generate route
wheels generate resource
wheels generate api-resource
wheels generate frontend
wheels generate test
wheels generate snippets
wheels scaffold
wheels db create
wheels db drop
wheels db setup
wheels db reset
wheels db status
wheels db version
wheels db rollback
wheels db seed
wheels db dump
wheels db restore
wheels db shell
wheels db schema
wheels dbmigrate info
wheels dbmigrate latest
wheels dbmigrate up
wheels dbmigrate down
wheels dbmigrate reset
wheels dbmigrate exec
wheels dbmigrate create blank
wheels dbmigrate create table
wheels dbmigrate create column
wheels dbmigrate remove table
wheels test
wheels test run
wheels test coverage
wheels test debug
wheels config list
wheels config set
wheels config env
wheels env
wheels env setup
wheels env list
wheels env switch
wheels environment
wheels console
wheels runner
wheels server
wheels server start
wheels server stop
wheels server restart
wheels server status
wheels server log
wheels server open
wheels plugins
wheels plugins list
wheels plugins install
wheels plugins remove
wheels analyze
wheels analyze code
wheels analyze performance
wheels analyze security
wheels security
wheels security scan
wheels optimize
wheels optimize performance
wheels docs
wheels docs generate
wheels docs serve
wheels ci init
wheels docker init
wheels docker deploy
wheels deploy
wheels deploy audit
wheels deploy exec
wheels deploy hooks
wheels deploy init
wheels deploy lock
wheels deploy logs
wheels deploy proxy
wheels deploy push
wheels deploy rollback
wheels deploy secrets
wheels deploy setup
wheels deploy status
wheels deploy stop
Configuration Management
Creating Commands
Service Architecture
Migrations Guide
Testing Guide
Object Relational Mapping
Creating Records
Reading Records
Updating Records
Deleting Records
Column Statistics
Dynamic Finders
Getting Paginated Data
Associations
Nested Properties
Object Validation
Object Callbacks
Calculated Properties
Transactions
Dirty Records
Soft Delete
Automatic Time Stamps
Using Multiple Data Sources
description: >- Wheels automatically wraps your database calls in transactions to assist your application in maintaining data integrity. Learn how to control this functionality.
Transactions
Database transactions are a way of grouping multiple queries together. They are useful in case the outcome of one query depends on the completion of another. For example, if you want to take money from one person's bank account, and transfer it into someone else's, you probably want to make sure the debit completes before running the credit.
You'll be pleased to know that Wheels makes using database transactions easy. In fact, the vast majority of the time, you won't need to think about using them at all because Wheels automatically runs all queries within the callback chain as a single transaction for creates, updates, and deletes.
If any of the callbacks within the chain return false, none of the queries will commit.
For example, say you want to automatically create the first post when a new author subscribes to a blog.
In your Author model, you would add the following code:
{% code title="Author.cfc" %}
component extends="Model" {
function config(){
afterCreate("createFirstPost");
}
function createFirstPost(){
var post = model("post").new(
authorId=this.id,
text="This is my first post!";
post.save();
}
}
{% endcode %}
In this example, if the post doesn't save (perhaps due to a validation problem), the author doesn't get created either. This helps to maintain database integrity.
Disabling Transactions
If you want to manage transactions yourself using the <cftransaction> tag, you can simply add transaction=falseto any CRUD method.
model("author").create(name="John", transaction=false);
Another option is to disable transactions across your entire application using the transactionMode configuration:
{% code title="/config/settings.cfm" %}
set(transactionMode=false);
{% endcode %}
See the chapter about Configuration and Defaults for more details.
Using Rollbacks
Sometimes it's useful to use a rollback to test a process without making any permanent changes to the database. To do this, add transaction="rollback" to any CRUD method.
model("author").create(name="John", transaction="rollback");
Again, to configure your entire application to rollback all transactions, you can set the transactionMode configuration to rollback.
{% code title="/config/settings.cfm" %}
set(transactionMode="rollback");
{% endcode %}
Nesting Transactions with invokeWithTransaction
One issue with ColdFusion is that you cannot nest <cftransaction> tags. In this case, Wheels provides a workaround. If you wish to run a method within a transaction, use invokeWithTransaction(), as below.
invokeWithTransaction(
method="transferFunds",
personFrom=david,
personTo=mary,
amount=100
);