How to exclude some fields when listing Grails domain?

Question

I'm wondering how can I list Grails domain and exclude some fields at same time. I'm guessing solution must be simple but I just can not see it.

I prepared some example with domain User:

class User implements Serializable {
    String username
    String email
    Date lastUpdated
    String password
    Integer status

    static constraints = { }  

    static mapping = { }
}

At this point I want to list all users which have status below 2.

render User.findAllByStatusLessThen(2) as JSON

I want to render JSON response to clientside without some fields. For example I just want to render users with fields username and lastUpdated so rendered JSON would look like this:

[{"username": "user1", "lastUpdated":"2016-09-21 06:49:46"}, {"username": "user2", "lastUpdated":"2016-09-22 11:24:42"}]

What's the easiest way to achieve that?

Abhinandan Satpute · Accepted Answer · 2016-09-23T09:30:01.933

3

Yeah.It's simple.Try below solutions

Solution 1

List userList = User.where{ status < 2 }.property("username").property("lastUpdated").list()

render userList as JSON

output

   [{"user1", "2016-09-21 06:49:46"}, {"user2", "2016-09-22 11:24:42"}]

Solution 2 - using this you will get output in the Key-Value pair

List userList = User.findAllByStatusLessThen(2)?.collect{
    [username : it.username, lastUpdated: it.lastUpdated]}

render userList as JSON

output

    [{"username": "user1", "lastUpdated":"2016-09-21 06:49:46"}, {"username": "user2", "lastUpdated":"2016-09-22 11:24:42"}]

edited Sep 23 '16 at 09:30

answered Sep 23 '16 at 07:15

Abhinandan Satpute

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Thank you for your input. Solution 2 suits the best in my case. – matox Sep 23 '16 at 08:36

score 2 · Answer 2 · answered Sep 23 '16 at 07:18

2

You are looking for Grails projections.

def result = Person.createCriteria().list {
    lt("status", 2)
    projections {
        property('username')
        property('lastUpdated')
    }
} as JSON

answered Sep 23 '16 at 07:18

Mike B

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score 1 · Answer 3 · answered Sep 23 '16 at 07:37

Well if you want the result to be in key-value pair you can take advantage of HQL query

def query = """select new map(u.username as username, u.lastUpdated as lastUpdated) from User u where status < 2"""  
def result = User.executeQuery(query)
println (result as JSON)

This will give you the output as below

[{"username": "user1", "lastUpdated":"2016-09-21 06:49:46"}, {"username": "user2", "lastUpdated":"2016-09-22 11:24:42"}]

How to exclude some fields when listing Grails domain?

3 Answers3