Summary A parent can have many children. How do you write a service such that, if after adding a parent there is an error when adding a child, the entire transaction is rolled back. For example, add parent p1, successfully add child c1, then when adding child c2 an error occurs, both p1 and c1 should be rolled back.
Detailed Problem
In the following code, there is a unique constraint on the name property of the child. So if you try to add the same name twice with a different parent, then the child record should not be added and the parent record should be rolled back.
My problem is that the parent record is not being rolled back.
I am using MySQL w/ InnoDB with Grails 1.2-M2 and Tomcat 6.018.
Data Source
import org.codehaus.groovy.grails.orm.hibernate.cfg.GrailsAnnotationConfiguration
dataSource {
configClass = GrailsAnnotationConfiguration.class
pooled = true
driverClassName = "com.mysql.jdbc.Driver"
dialect = org.hibernate.dialect.MySQLInnoDBDialect
zeroDateTimeBehavior="convertToNull" //Java can't convert ''0000-00-00 00:00:00' to TIMESTAMP
username = "root"
password = "12345"
loggingSql=false
}
hibernate {
cache.use_second_level_cache=true
cache.use_query_cache=true
cache.provider_class='com.opensymphony.oscache.hibernate.OSCacheProvider'
}
// environment specific settings
environments {
development {
dataSource {
dbCreate = "create-drop" // one of 'create', 'create-drop','update'
url = "jdbc:mysql://localhost:3306/transtest?zeroDateTimeBehavior=convertToNull"
}
}
test {
dataSource {
dbCreate = "update"
url = "jdbc:mysql://localhost:3306/transtest?zeroDateTimeBehavior=convertToNull"
}
}
production {
dataSource {
dbCreate = "update"
url = "jdbc:mysql://localhost:3306/transtest?zeroDateTimeBehavior=convertToNull"
}
}
}
I have the following simple domain classes:
Parent:
class Parent {
static hasMany = [ children : Child ]
String name
static constraints = {
name(blank:false,unique:true)
}
}
Child
class Child {
static belongsTo = Parent
String name
Parent parent
static constraints = {
name(blank:false,unique:true)
}
}
Simple Data Entry GSP
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Sample title</title>
</head>
<body>
<h1>Add A Record</h1>
<g:form action="add" name="doAdd">
<table>
<tr>
<td>
Parent Name
</td>
<td>
Child Name
</td>
</tr>
<tr>
<td>
<g:textField name="parentName" />
</td>
<td>
<g:textField name="childName" />
</td>
</tr>
<tr><td><g:submitButton name="update" value="Update" /></td></tr>
</table>
</g:form>
</body>
</html>
Controller
class AddrecordController {
def addRecordsService
def index = {
redirect action:"show", params:params
}
def add = {
println "do add"
addRecordsService.addAll(params)
redirect action:"show", params:params
}
def show = {}
}
Service
class AddRecordsService {
// boolean transactional = true //shouldn't this be all I need?
static transactional = true // this should work but still doesn't nor does it work if the line is left out completely
def addAll(params) {
println "add all"
println params
def Parent theParent = addParent(params.parentName)
def Child theChild = addChild(params.childName,theParent)
println theParent
println theChild
}
def addParent(pName) {
println "add parent: ${pName}"
def theParent = new Parent(name:pName)
theParent.save()
return theParent
}
def addChild(cName,Parent theParent) {
println "add child: ${cName}"
def theChild = new Child(name:cName,parent:theParent)
theChild.save()
return theChild
}
}
You also need to make sure a RuntimeException is thrown inside the service in order for the transaction to be automatically rolled back.
So I'd do this:
def addParent(pName) {
println "add parent: ${pName}"
def theParent = new Parent(name:pName)
if(!theParent.save()){
throw new RuntimeException('unable to save parent')
}
return theParent
}
def addChild(cName,Parent theParent) {
println "add child: ${cName}"
def theChild = new Child(name:cName,parent:theParent)
theChild.save()
if(!child.save()){
throw new RuntimeException('unable to save child')
}
return theChild
}
and then catch exceptions in the controller and render the errors.
The other way is to turn of automatic transactions and use Parent.withTransaction and manually mark the transaction for rollback if there is a validation error.
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