executequery in Grails doesn't load key : value json - mysql

I m doing something like this to get the data...
def prods = Product.executeQuery("select category.id,category.name, avg(competition1Price), avg(competition2Price), avg(onlineCompetitionPrice) from Product group by category.id")
render prods as JSON
Not the output I'm getting is this..
[[1,"Colchones y",1657.4784,2071.5,1242.5]]
these are just the values..
I want to use the same query and get key value pair..
like the way you do using findAll(query)
But I can't seem to implement this query using findAll()
Please Help
Thanks..

That's because the instances of prods are just objects with the result of your query and not instances of Product or other domain class (you used HQL that not represents a domain class). You can:
consider using a view for this query and mapping as a domain class;
manually build the output;
The second option is something like (not tested):
def output = [[:]]
prods.each { result ->
def prod = ['category.id' : result[0] , 'category.name': result[1]] //and so on...
output << prod
}
render output as JSON
Using this second option, to change the result produced, just cange the structure of your map. You can also have a list of maps if needed.

Related

DynamoDB JSON response parsing prints vertically

I have a script that scans a DynamoDB table that stores my instance IDs. Then I try to query another table to see if it also has that same instance and get all of the metadata attributes in a master table. When I iterate through the query using the instance ID from the initial scan of the first table, I am noticing each character of the instance id string is being printed to a new line, instead of the entire string on one line. I am confused how to fix this. Below is my code, sample output, and the expected output.
CODE:
import boto3
import json
from boto3.dynamodb.conditions import Key, Attr
def table_diff():
dynamo = boto3.client('dynamodb')
dynamodb = boto3.resource('dynamodb')
table_missing = dynamodb.Table('RunningInstances')
missing_response = dynamo.scan(TableName='CWPMissingAgent')
for instances in missing_response['Items']:
instance_id = instances['missing_instances']['S']
# This works how I want, prints i-xxxxx
print(instance_id)
for id in instance_id:
# This does not print how I want (vertically)
print(id)
query_response = table_missing.query(KeyConditionExpression=Key('ID').eq(id))
OUTPUT:
i
-
x
x
x
x
x
EXPECTED OUTPUT:
i-xxxxx
etc etc
instance_id is a string. Thus, when you loop over it (for id in instance_id), you are actually looping over each character in the string, and printing them out individually.
Why do you try to loop over it, when you say that just printing it produces the correct result?

How to pass RawQuerySet result as a JSONResponse in DJango?

I have two models like this:
class McqQuestion(models.Model):
mcq_question_id = models.IntegerField()
test_id = models.ForeignKey('exam.Test')
mcq_right_answer = models.IntegerField()
class UserMcqAnswer(models.Model):
user = models.ForeignKey('exam.UserInfo')
test_id = models.ForeignKey('exam.Test')
mcq_question_id=models.ForeignKey('exam.McqQuestion')
user_answer = models.IntegerField()
I need to match the user_answer and mcq_right_answer. Able to do that by executing the below raw query.
rightAns=UserMcqAnswer.objects.raw('SELECT B.id, COUNT(A.mcq_question_id) AS RightAns\
FROM exam_mcqquestion AS A\
LEFT JOIN exam_usermcqanswer AS B\
ON A.mcq_question_id=B.mcq_question_id_id\
WHERE B.test_id_id=%s AND B.user_id=%s AND\
A.mcq_right_answer=B.user_answer',[test_id,user_id])
1) But the problem is that couldn't able to pass the result as JSONResponse because it says TypeError: Object of type 'RawQuerySet' is not JSON serializable
2) Is there any alternative to this raw query by using the objects and filtered querysets?
Django's serialize function's second argument can be any iterator that yields Django model instances.
So, in principle, you can use that raw SQL query that you worked on, using something like this:
query = """SELECT B.id, COUNT(A.mcq_question_id) AS RightAns\
FROM exam_mcqquestion AS A\
LEFT JOIN exam_usermcqanswer AS B\
ON A.mcq_question_id=B.mcq_question_id_id\
WHERE B.test_id_id=%s AND B.user_id=%s AND\
A.mcq_right_answer=B.user_answer"""%(test_id, user_id)
and then getting the json data you'll return, as:
from django.core import serializers
data = serializers.serialize('json', UserMcqAnswer.objects.raw(query), fields=('some_field_you_want', 'another_field', 'and_some_other_field'))
Good luck finding the best way to solve your issue
Edit: small fix, added an import
Using raw query is not recommended in Django.
When the model query APIs don’t go far enough, you can fall back to writing raw SQL.
In your case model query API can solve your problem. You can use the following view:
views.py
def get_answers(request):
test = Test.objects.get(name="Test 1")
answers = UserMcqAnswer.objects.filter(test_id=test, user=request.user).annotate(
is_correct=Case(
When(user_answer=F('mcq_question_id__mcq_right_answer'),
then=Value(True)),
default=Value(False),
output_field=BooleanField())
).values()
return JsonResponse(list(answers), safe=False)
Also you can consider Django Rest Framework for serialization of QuerySet.

find row in ruby array

I have a mysql query that returns this type of data:
{"id"=>1, "serviceCode"=>"1D00", "price"=>9.19}
{"id"=>2, "serviceCode"=>"1D01", "price"=>9.65}
I need to return the id field based on a match of the serviceCode.
i.e. I need a method like this
def findID(serviceCode)
find the row that has the service code and return the ID
end
I was thinking of having a serviceCodes.each do |row| method and loop through and essentially go
if row == serviceCode
return row['id']
end
is there a faster / easier way?
You can use the method Enumerable#find:
service_codes = [
{"id"=>1, "serviceCode"=>"1D00", "price"=>9.19},
{"id"=>2, "serviceCode"=>"1D01", "price"=>9.65}
]
service_codes.find { |row| row['serviceCode'] == '1D00' }
# => {"id"=>1, "serviceCode"=>"1D00", "price"=>9.19}
If you use Rails Active Record as ORM and your Model named Product (only for example),
you can use something like this:
def findID(serviceCode)
Product.select(:id).where(serviceCode: serviceCode).first
end
If you have plain SQL Query in plain ruby class (not recommended), you should change this query to get only the id, as Luiggi mentioned. But aware of SQL Injections if your serviceCode coming from external Requests.

Play + Slick: How to do partial model updates?

I am using Play 2.2.x with Slick 2.0 (with MYSQL backend) to write a REST API. I have a User model with bunch of fields like age, name, gender etc. I want to create a route PATCH /users/:id which takes in partial user object (i.e. a subset of the fields of a full user model) in the body and updates the user's info. I am confused how I can achieve this:
How do I use PATCH verb in Play 2.2.x?
What is a generic way to parse the partial user object into an update query to execute in Slick 2.0?I am expecting to execute a single SQL statement e.g. update users set age=?, dob=? where id=?
Disclaimer: I haven't used Slick, so am just going by their documentation about Plain SQL Queries for this.
To answer your first question:
PATCH is just-another HTTP verb in your routes file, so for your example:
PATCH /users/:id controllers.UserController.patchById(id)
Your UserController could then be something like this:
val possibleUserFields = Seq("firstName", "middleName", "lastName", "age")
def patchById(id:String) = Action(parse.json) { request =>
def addClause(fieldName:String) = {
(request.body \ fieldName).asOpt[String].map { fieldValue =>
s"$fieldName=$fieldValue"
}
}
val clauses = possibleUserFields.flatMap ( addClause )
val updateStatement = "update users set " + clauses.mkString(",") + s" where id = $id"
// TODO: Actually make the Slick call, possibly using the 'sqlu' interpolator (see docs)
Ok(s"$updateStatement")
}
What this does:
Defines the list of JSON field names that might be present in the PATCH JSON
Defines an Action that will parse the incoming body as JSON
Iterates over all of the possible field names, testing whether they exist in the incoming JSON
If so, adds a clause of the form fieldname=<newValue> to a list
Builds an SQL update statement, comma-separating each of these clauses as required
I don't know if this is generic enough for you, there's probably a way to get the field names (i.e. the Slick column names) out of Slick, but like I said, I'm not even a Slick user, let alone an expert :-)

Working around LinqToSQls "queries with local collections are not supported" exception

So, I'm trying to return a collection of People whose ID is contained within a locally created collection of ids ( IQueryable)
When I specify "locally created collection", I mean that the Ids collection hasnt come from a LinqToSql query and has been programatically created (based upon user input).
My query looks like this:
var qry = from p in DBContext.People
where Ids.Contains(p.ID)
select p.ID;
This causes the following exception...
"queries with local collections are not supported"
How can I find all the People with an id that is contained within my locally created Ids collection?
Is it possible using LinqToSql?
If Ids is a List, array or similar, L2S will translate into a contains.
If Ids is a IQueryable, just turn it into a list before using it in the query. E.g.:
List<int> listOfIDs = IDs.ToList();
var query =
from st in dc.SomeTable
where listOfIDs.Contains(st.ID)
select .....
I was struggling with this problem also. Solved my problem with using Any() instead
people.Where(x => ids.Any(id => id == x.ID))
As the guys mentioned above, converting the ids, which is of type IQueryable to List or Array will solve the issue, this will be translated to "IN" operator in SQL.But be careful because if the count of ids >= 2100 this will cause another issue which is "The server supports a maximum of 2100 parameters" and that is the maximum number of parameters(values) you can pass to "IN" in SQL server.
Another alternative would be keeping ids as IQueryable and using LINQ "Any" operator instead of "Contains", this will be translated to "EXISTS" in SQL server.
I'm sorry but the answers here didn't work for me as I'm doing dynamic types further along.
What I did was to use "UNION" in a loop which works great. Here's how:
var firstID = cityList.First().id;
var cities = dc.zs_Cities.Where(c => c.id == firstID);
foreach(var c in cityList)
{
var tempCity = c;
cities = cities.Union(dc.zs_Cities.Where(cty => cty.id == tempCity.id));
}