We must save a entity which holds a list of date objects. The list is annotated as follows:
#ElementCollection
#Temporal(TemporalType.DATE)
public List<Date> dates {
return dates;
}
This works but the dates are mapped with varchar type in database. Is there another way to store a collection of dates in the database?
That is odd, it should use the DATE type. I assume you are using EclipseLink to generate your DDL?
You could set the column definition using the #Column annotation to set the type explicitly.
(also try the latest EclipseLink release, and if it still fails log a bug).
Related
I'm fetching data from database. I'm saving my data in string format like this
23,32
while fetching data from database my output is like
[{"transaction_id":"28,34"}]
but i want the out put in this format
[{"transaction_id":"28"},{"transaction_id":"34"}]
I'm not able to find the proper solution
You might want to mutate the data you're getting back with access mutator like:
public function getTransactionIdAttribute()
{
return //logic you want to apply to $this->transaction_id
}
But I suspect what you actually should do is set up your database relationship as many-to-many and make a join table that holds your transaction ids.
I have an array of bytes in my model
public byte[] created_dt { get; set; }
It represents a timestamp value in the database.
In my view , I am referring it as #model.created_dt
but it is coming as system.byte[]
How to resolve this?
Try as this is just an example to achieve the functionality
#foreach(var a in model.created_dt){
<label>#a</label>
}
Judging by the behavior, this looks like ASP.NET and you are simply seeing the output of an implicit call to ToString() on the array (the default way of displaying anything that does not have a template defined). You will have to do something with the raw byte data and present it to the user.
Since you refer to "timestamp" and the property name might suggest a record creation time, you may want to write a helper method to translate this raw data to a DateTime which you could then format accordingly.
However, one of the following is most likely true:
It strikes me as odd that you are using raw binary to store what should otherwise be a datetime2 column. (Or it is a datetime in your database but you're doing something unorthodox to retrieve the value.)
Your property/column name of "created_dt" is a misnomer and it is really a timestamp (i.e. rowversion) column. In which case I don't think this is something a user would know what to do with, and it probably doesn't belong on the UI.
When I use criteria queries, the result contains array list of lazy initialized objects. that is, the list has values with handler org.codehaus.groovy.grails.orm.hibernate.proxy.GroovyAwareJavassistLazyInitializer.
This prevent me from doing any array operation (minus, remove etc) in it. When I use, GORM methods, I get array list of actual object types. How can I get the actual objects in criteria query?
The code is listed below.
availableTypes = Type.withCriteria() {
'in'("roleFrom", from)
'in'("roleTo", to)
}
availableTypes (an array list) has one value , but not actual object but value with a handler of GroovyAwareJavassistLazyInitializer
availableTypes (an array list) has values with type Type
availableTypes = Type.findByRoleFrom(from)
---------- Update ----------
I did further troubleshooting, and this is what I found. Probably the above description might be misleading, but I kept it in case it helps.
When using findAllBy for the first time, I get proxy objects rather than the actual instance. Then, I invoke the method through an ajax call, the actual instance is loaded (anything to do with cache loading??). When I refresh the page, it again loads the proxy
def typeFrom = Type.findAllByParty(partyFrom)
there is another use of findAllBy in the same method, which always returns actual instances.
def relFrom = Relation.findAllByParty(partyFrom)
When compared the two classes, the attribute 'party' of class Roles is part of a 1-m relation. like
class Role {
RoleType roleType
LocalDate validFrom
LocalDate validTo
static belongsTo = [party : Party ]
...
}
I know if I do statement like Party.findAll(), the role instances would be proxy till they access. But, when using gorm directly on the class (Role), why I am getting the proxy objects ???
thanks for the help.
thanks.
Turns out are a couple of possible solutions which I came across but didn't try, such as
Overloading the equals method so that the proxy and the domain
object use a primary key instead of the hashCode for equality
Using a join query so that you get actual instances back and not proxies
GrailsHibernateUtil.unwrapProxy(o)
HibernateProxyHelper.getClassWithoutInitializingProxy(object)
One solution that worked for me was to specify lazy loading to be false in the domain object mapping.
History of this problem seems to be discussed here: GRAILS-4614
See also: eager load
I know this is simple question but taking more time
How to find first record from table in grails .
I need to get only the first record with out knowing the id number .
Is there any method like find :first in grails ?
thanks in advance .
Updating to Grails 2.1.1 or later adds two new methods (first and last) for GORM to address this needed feature.
From the docs:
class Person {
String firstName
String lastName
Integer age
}
// retrieve the first person ordered by the identifier
def p = Person.first()
// retrieve the first person ordered by the lastName property
p = Person.first(sort: 'lastName')
// retrieve the first person ordered by the lastName property
p = Person.first('lastName')
Well, you have to define by what measure this record is supposed to be the "first".
Assuming that you mean the record with the earliest creation timestamp, the easiest and most robust approach would be to add a dateCreated property to your domain class and then querying for the entity with the lowest such date. In fact you don't even have to set the creation date manually, because Grails does this for you (as long as you name the property dateCreated) - see Automatic timestamping in the Grails Documentation.
The HQL query would be something like:
def firstObject = YourClass.find("FROM YourClass ORDER BY dateCreated")
Check out hibernate criteria and projections, e.g:
def location = Location.createCriteria()
def firstRecord = location.list{
maxResults(1)
order("id","asc")//assuming auto increment just to make sure
}[0]
http://grails.org/doc/1.0.3/ref/Domain%20Classes/createCriteria.html
If timestamp doesn't matter, you could try if Daniel's answer without ORDER BY works, i.e.
def firstObject = YourClass.find("FROM YourClass")
You can use the grails findBy methods to return the first result of a query.
-> From the 1.3.7 docs
findBy*
Purpose
Dynamic method that uses the properties of the domain class to allow
the creation of Grails query method expressions that return the first
result of the query
-> from the latest docs
findBy* Purpose
Dynamic method that uses the properties of the domain class to execute
a query returning the first matching result.
I have a domain class which has two dates in it and I want one of them populated with the current time when a record is created for the object, like a create timestamp...
class Contact {
Date initiatedDate
Date acceptedDate
}
Is it sufficient just to new a Date object on one of them and make the other nullable until such a time as I need to fill it, sort of like this...
class Contact {
static constraints =
{
acceptedDate(nullable:true)
}
Date initiatedDate = new Date()
Date acceptedDate
}
I'm experimenting, but I would like to know whether this is the right way to go about it or whether there is something more Grailsy or GORMy I should do in, say, an init function or by tweaking the domain object definition to have one by default, like it does an id and version.
Thanks
What you've written should work but you can use the GORM auto-timestamping feature by simply adding a field:
class Contact {
Date dateCreated
}
If you want to keep your own names for the fields the same grails docs also show you how to use GORM events to set fields on save or update.
HTH