gorm projection and loss of metainformation - grails

When using projection on the properties, the result is returned as the list with the elements in the same sequence as that defined in the projections block. At the same time the property names are missing from the list and that is really disadvantageous to the developer as the result would be passed along and the caller needs to know what value belongs to which property. Is there a way to return a map from the Criteria query with property name as the key to the value?
so, the following code:
def c = Trade.createCriteria()
def remicTrades = c.list {
projections {
property('title', 'title')
property('author.name', 'author')
}
def now = new Date()
between('publishedDate', now-365, now)
}
This returns:
[['book1', 'author1']['book2', 'author2']]
Instead I would like it to return:
[[book:'book1', author:'author1'][book:'book2', author:'author2']]
I know I can arrange this way after getting the result but I earnestly feel that the property alias should have been used by the criteria to return a list of map that mimics the result of the SQL query and not a bland list.

Duplicate: Grails queries with criteria: how to get back a map with column?
And the corresponding answer (and solution): https://stackoverflow.com/a/16409512/1263227
Use resultTransformer.
import org.hibernate.criterion.CriteriaSpecification
Trade.withCriteria {
resultTransformer(CriteriaSpecification.ALIAS_TO_ENTITY_MAP)
projections {
property('title', 'title')
property('author.name', 'author')
}
def now = new Date()
between('publishedDate', now-365, now)
}

Agree with your question reasoning, this really should be part of the core GORM solution. That said, here's my workaround;
def props = ['name','phone']
def query = Person.where {}.projections {
props.each{
property(it)
}
}
def people = query.list().collect{ row->
def cols = [:]
row.eachWithIndex{colVal, ind->
cols[props[ind]] = colVal
}
cols
}
println people // shows [['name':'John','phone':'5551212'],['name':'Magdalena','phone':'5552423']]

Related

How to pass variable holding a value to groovy eq query?

How can I pass variable holding a value instead of passing a value directly to groovy search criteria?
for (def payee in payees)
{
def results = resp.cases.find("eq 'hrid','7547') // hard code values work
def results = resp.cases.find("eq 'hrid',??????) // how can I pass payee
}
I'm new to this. Please help. thanks
Basing on examples, check it:
def results = resp.cases.find { case -> case.hrid == payee }
GORM criteria queries are quite different than your example. Let's say you have a Payee domain class with a property named hrid:
grails-app/domain/com/something/Payee.groovy
class Payee {
String hrid
}
To get a list of all the Payee instances with an hrid of 7547, you'd run a criteria query like this:
String hridValue = '7547'
List payees = Payee.withCriteria {
eq 'hrid', hridValue
}
I explain Grails GORM queries in depth in a series of articles starting right here.

How do I write a createCriteria in grails which pull only few columns from the table instead of all columns?

How do I write a createCriteria in grails which pull only few columns from the table instead of all columns?
I have a table called Ads. I want to retrieve only columns "Title" , "Price" and "Photo".
def c = Classified.createCriteria()
def records = c.list {
eq('publish_date', '2014-06-06')
}
maxResults(8)
}
Above query retrieves all the records. How to restrict to only few columns?
You can use projections to achieve this - at the simplest
projections {
property('title')
property('price')
property('photo')
}
would cause c.list to return a list of three-element lists, where records[n][0] is the title, records[n][1] is the price etc. If you want to be able to access the properties by name rather than by number then you need to assign aliases and use a result transformer
import org.hibernate.transform.AliasToEntityMapResultTransformer
def c = Classified.createCriteria()
def records = c.list {
eq('publish_date', '2014-06-06')
maxResults(8)
projections {
// first param is the property name, second is the alias definition -
// typically you'd leave them the same but here I make them different
// for demonstration purposes
property('title', 'ttl')
property('price', 'cost')
property('photo', 'picture')
}
resultTransformer(AliasToEntityMapResultTransformer.INSTANCE)
}
Now records will be a list of maps rather than a list of lists, and you can access the projected properties by alias name - records[n].ttl, records[n].cost, etc.
Try this:
def records = Classified.withCriteria {
eq('publish_date', '2014-06-06')
projections {
property('title')
property('price')
property('photo')
}
maxResults(8)
}

Grails - How to get list of distinct User Objects

Is there a way that, i can get list of distinct User objects(based on username). And still get result as a List of User Objects rather than, List of username's.
My code is
def criteria = User.createCriteria()
def users = criteria.list() {
projections {
distinct("username")
}
setResultTransformer(CriteriaSpecification.ROOT_ENTITY)
}
return users
Currently am getting List of the usernames, not User.
Ya projection is like filtering and selecting by username you should change it to
def criteria = User.createCriteria()
def users = criteria.listDistinct() {
projections {
groupProperty("username")
}
}
return users
JOB DONE!
One of these should work - I haven't tested any of them, I leave that up to you :)
User.list().unique()
User.list().unique() with the equals() method on the User domain class overridden to compare objects using the username
User.list().unique { it.username } (might need toArray() after list())
def criteria = User.createCriteria()
def users = criteria.list() {
projections {
distinct("username")
}
setResultTransformer(CriteriaSpecification.ROOT_ENTITY)
}
Just replace setResultTransformer(CriteriaSpecification.ROOT_ENTITY) with resultTransformer(ALIAS_TO_ENTITY_MAP). You will get a list of string as a result
otherwise just replace .list with .listDistinct and use do not need distinct("username"), just can be property("username");
Usually people get problems with pagination. not results. If you already had something like:
User.createCriteria().list([max:params.max,offset:params.offset],{
createAlias("others", "others", CriteriaSpecification.LEFT_JOIN);
ilike("others.firstName", "%${query}%");
});
It could result in row duplicates. Because .listDistinct() does not support pagination, just add
resultTransformer(CriteriaSpecification.DISTINCT_ROOT_ENTITY);
So query will look like this:
User.createCriteria().list([max:params.max,offset:params.offset],{
resultTransformer(CriteriaSpecification.DISTINCT_ROOT_ENTITY);
createAlias("others", "others", CriteriaSpecification.LEFT_JOIN);
ilike("others.firstName", "%${query}%");
});
Where ever you got a collection (list, array, ...) (I don't know if work with any type of collection, but work in all that i could test). Use unique{ it.property }:
Example:
def users = []
for (def room in rooms) {
users.addAll(room.users)
}
return users.unique{ it.id }
Using where query(Detached criteria):
def userListQuery = User.where{
// Your search criteria
}
def userList = userListQuery.list().unique{ it.username }
it should result one query for distinct results.
This will get you the distinct user object based on userName
def userInstance = User.list().unique{ it.user_name}

How can I avoid redundancy in nearly identically criteria?

Imagine I have the following query:
def result = Test.createCriteria().list(params) {
// image here a lot of assocs, criterias, ...
}
In many cases you need the row count of the query above, e.g. list actions of many controllers.
def resultTotal = Test.createCriteria().list(params) {
// Imagine here a lot of assocs, criterias, ...
// Change to the criteria above is only the projection block
projections { rowCount() }
}
How can I avoid this?
You can:
Extract the Criteria creation to a conditional factory/builder method;
Use named queries;
Use named query parameters (and Groovy code!) to alter the query "on the fly", like:
.
static namedQueries = {
byLocation { Location location ->
if (location) {
... // some more criteria logic
}
}
}
If you aren't paginating the results of the query, you can simply do the following after the first query is invoked:
def resultTotal = result?.size()
For the same set of query being used at many places, I create them as a closure and change its delegate to the criteria in question.
For example :
def query = {
projections{
rowCount()
}
eq('type', myType)
}
def criteria = Customer.createCriteria()
query.delegate = criteria
myType = CustomerType.guest
List records = criteria.list(params) {
query()
}
I use totalCount like this:
def list() {
def myInstanceList = MyInstance.createCriteria().list(params){
eq('name', params.name)
}
[myInstanceList: myInstanceList, myInstanceListTotal: myInstanceList.totalCount]
}

Is there a 'not in' equivalent in GORM?

Is this possible to convert in createCriteria()?
SELECT * FROM node WHERE (node.type = 'act' AND nid NOT IN (SELECT nid FROM snbr_act_community)) LIMIT 10
I know there's a 'in' operator and here's what I have so far:
def c = VolunteerOpportunity.createCriteria()
def matchingActs = c.list {
node {
eq('type', 'act')
}
maxResults(10)
}
Just want to see if this is possible. Otherwise, I guess this is possible in HQL right?
thanks Sammyrulez for the code. got an idea from that. tested it but it didn't work. i fixed it and here's the final working code:
def ids = [14400 as long, 14401 as long]
def c = VolunteerOpportunity.createCriteria()
def matchingActs = c.list {
node {
eq('type', 'act')
not { 'in'(ids) }
}
maxResults(10)
}
now i know how to use 'not' operator. thanks a lot!
not tried it myself but looking at the Grails doc and hibernate api you create nodes on this builder map with the static methods found in the Restrictions class of the Hibernate Criteria API 1. So something like
def c = VolunteerOpportunity.createCriteria()
def matchingActs = c.list {
node {
not(in('propertyName', ['val1','val2']))
}
maxResults(10)
}
Since you chain the in method (that returns a Criterion) with the not method (that takes a Criterion as argument and returns a negated version)
this is the solution :
def resultat=EnteteImputationBudgetaire.createCriteria().get{
between("dateDebutPeriode", dateDebut, dateFin)
and{ eq 'natureImputationBudgetaire','FONCTIONNEMENT' }
maxResults(1)
}
def resultat2=ParametragePlanBudgetaire.createCriteria().list() {
like('composantBudgetaire','6%')
if(resultat?.details) {
not {
'in'('composantBudgetaire',resultat?.details?.imputationBudgetaire)
}
}
}
According to Grails documentation about creating criteria here, you can use something like this:
not {'in'("age",[18..65])}
In this example, you have a property named "age" and you want to get rows that are NOT between 18 and 65. Of course, the [18..65] part can be substituted with any list of values or range you need.
Just remembering: in this case you don't have to use parenthesis and you can use inList, for example:
not { inList 'age',[18..65] }

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