This question is very similar to How to query MongoDB with "like"?, yet I have not been able to use that or the documentation here https://docs.mongodb.com/manual/reference/operator/query/regex/ to figure out the query that I need.
I need to find documents in a mongo collection which has values of following format in a field:
"key->some_name::details->(value = '{wild_card_value_here}'):sort->by_name"
In SQL this query would look like
SELECT * from some_Table where field like 'key->some_name::details->(value = ''%''):sort->by_name'
Note that single quote is part of the string
Here's what I tried with mongo:
db.getCollection('collection_name').find({"some_field":{$regex:/^key->some_name::details->(value = '.*'):sort->by_name/}})
But it returns 0 documents. I also tried this which did not work either:
db.getCollection('collection_name').find({"some_field":"key->some_name::details->(value = '/.*/'):sort->by_name"})
I'm unsure if the syntax itself is issue or the special characters in the string like , -> : etc.
EDIT:
Example document that I want to be found:
{
...
"some_field":"key->some_name::details->(value = 'id_1'):sort->by_name"
...
}
and
{
...
"some_field":"key->some_name::details->(value = 'id_2'):sort->by_name"
...
}
Turns out this was a matter of escaping special characters ( and ), The query that worked is:
db.getCollection('collection_name').find({"some_field":{$regex:/^key->some_name::details->\(value = '.*'\):sort->by_name/}})
Related
I created a quill query, which should find some data in database by given parameter:
val toFind = "SomeName"
val query = query.find(value => infix"$value = ${lift(toFind)}".as[Boolean])
It works fine when for example I have data in database "SomeName", but if I want to have same results by passing there "somename" I found nothing. The problem is with data case-sensitive.
Is it possible to always find values with case-insensitive way? In quill docs I have not found anything about it.
Ok, I found a solution. It is enough to add LOWER() sql function to infix:
val query = query.find(value => infix"LOWER($value) = ${lift(toFind.toLowerCase)}".as[Boolean])
I am trying to make a complex query in swift to get data from DynamoDB.
I am able to get all information by using the userID. However there are times that I may not know the entirety of the userID and need to make a more complex query.
For instance, if I know the first name and the last name, and the user id format is "firstname:lastname:email", I need to be able to query all userID's that include the first and last name, then add a where for another column.
I am very new to dynamo and want to accomplish something like the sql query below.
SQL example:
SELECT * FROM mytable
WHERE column2 LIKE '%OtherInformation%'
AND (column1 LIKE '%lastname%' OR column1 LIKE '%firstname%')
Here is the code I have in swift4 for getting the userID if I know it exaclty, not entirely sure how to modify this for complex queries.
func queryDBForUser(Fname: String, Lname: String) {
let userId = Fname + "." + Lname + ":" + (UIDevice.current.identifierForVendor?.uuidString)!
self.UserId = userId
let objectMapper = AWSDynamoDBObjectMapper.default()
let queryExpression = AWSDynamoDBQueryExpression()
queryExpression.keyConditionExpression = "#userId = :userId"
queryExpression.expressionAttributeNames = ["#userId": "userId",]
queryExpression.expressionAttributeValues = [":userId": userId,]
objectMapper.query(CheckaraUsers.self, expression: queryExpression, completionHandler: {(response: AWSDynamoDBPaginatedOutput? ,error: Error?) -> Void in
if let error = error {
print("Amazon DynamoDB Error: \(error)")
return
}
I have also tried many variations along the lines of the following code, with no luck:
queryExpression.keyConditionExpression = "#FirstName = :firstName and #LastName = :lastName,"
queryExpression.expressionAttributeNames = ["#FirstName": "FirstName" , "#LastName": "LastName"]
queryExpression.expressionAttributeValues = [":FirstName": Fname,":LastName": Lname]
Any help would be greatly appreciated, thanks in advance!
You won't be able to do this with a DynamoDB query. When you query a table (or index) in DynamoDB you must always specify the complete primary key. In your case that would mean the full value of "firstname:lastname:email".
You could sort of do this with a DynamoDB scan and a filter expression, but that will look at every item in your table, so it could be slow and expensive. Amazon will charge you for the read capacity necessary to look at every item in the table.
So if you really wanted to, the filter expression for the scan operation would be something like:
"contains (#FirstName, :firstName) and contains (#LastName, : lastName)"
Note that contains looks for an exact substring match, so if you want case insensitive matches (like ILIKE in SQL) it won't work.
If you need to do these types of queries then you need to evaluate whether or not DynamoDB is the right choice for you. DynamoDB is a NoSQL key/value store basically. It trades limited querying functionality for scalability and performance. If you are coming at DynamoDB from a SQL background and are expecting to be able to do freeform queries of anything in your table, you will be disappointed.
Got the query working by adding a secondary index to my DynamoDB table, although this is not what I initially wanted, it still works as now I can query for a value that exists in both columns I needed, without doing a table scan and filtering after.
query code:
queryExpression.indexName = "Index-Name" queryExpression.keyConditionExpression = "#LastName = :LastName and #otherValue = :otherValue"
queryExpression.expressionAttributeNames = ["#LastName": "LastName" , "#otherValue": "otherValue"]
queryExpression.expressionAttributeValues = [":LastName": Lname,":otherValue": self.otherValue!]
I'm working on super simple search across multiple fields in a document to see if any of them has a single value. (Note: some fields are using regex to search if value is contained in string). Using query builder I constructed the following.
public function search($value, $limit, $offset=0, $orderby = '', $order='' )
{
$regexVal = new \MongoRegex('/^.*(\b'.str_replace(' ', '\s', $value).'\b).*?$/i');
$query = $this->repository->createQueryBuilder();
$query->addOr($query->expr()->field('location')->equals($regexVal));
$query->addOr($query->expr()->field('mappedData.name')->equals($regexVal));
$query->addOr($query->expr()->field('mappedData.first_name')->equals($regexVal));
$query->addOr($query->expr()->field('mappedData.last_name')->equals($regexVal));
$query->addOr($query->expr()->field('mappedData.email')->equals($value));
$query->addOr($query->expr()->field('email')->equals($value));
$query->addOr($query->expr()->field('organization')->equals($value));
$query->limit($limit)
->skip($offset);
if( ! empty($orderby) && $order ){
$query->sort($orderby, $order);
}
return $query->getQuery()->execute();
}
If I dump out the constructed query values I get the following array in this gist. https://gist.github.com/jchamb/04a0400c989cd28b1841 The extra association field in there is being added by a Doctrine Filter.
Through Query builder I don't get any results, however if I construct the query myself and run it in an admin app like genghis, I get the expected single document result.
Actual written mongodb string looks like this. https://gist.github.com/jchamb/ce60829480576a88290d
This project is a zend2 app that was already using doctrine and mongo. I'm not much of an expert with mongo in general so I'm not sure what i'm doing wrong inside of Query Builder that i'm not getting the same result as executing the query directly. I can't find any info on stack or the query builder docs that gives any extra clues for the multiple addOrs syntax either.
Any help or direction would be really appreciated, in the most basic form I need query builder to get a document where association = x and ( field1 = val or field2 = value).
Thanks!
Really unsure what the exact issue was with the above, but after playing around, switching the order of query builder around fixes the problem.
public function search($value, $limit, $offset=0, $orderby = '', $order='' )
{
$regexVal = new \MongoRegex('/^.*(\b'.str_replace(' ', '\s', $value).'\b).*?$/i');
$query = $this->repository->createQueryBuilder()
->find()
->limit($limit)
->skip($offset);
$query->addOr($query->expr()->field('location')->equals($regexVal));
$query->addOr($query->expr()->field('mappedData.name')->equals($regexVal));
$query->addOr($query->expr()->field('mappedData.first_name')->equals($regexVal));
$query->addOr($query->expr()->field('mappedData.last_name')->equals($regexVal));
$query->addOr($query->expr()->field('mappedData.email')->equals($value));
$query->addOr($query->expr()->field('email')->equals($value));
$query->addOr($query->expr()->field('organization')->equals($value));
if( ! empty($orderby) && $order ){
$query->sort($orderby, $order);
}
return $query->getQuery()->execute();
}
Would love to still hear some feedback about why this works and the above didn't if anyone know more about the internals of query builder.
My web application runs on MongoDB, using python and pyMongo. I get this scenario a lot - code that reads something like:
from pymongo import Connnection
users = Connection().db.users
def findUsers(firstName=None, lastName=None, age=None):
criteria = {}
if firstName:
criteria['firstName'] = firstName
if lastName:
criteria['lastName'] = lastName
if age:
criteria['age'] = age
query = users.find(criteria)
return query
I find that kind of messy how I need an if statement for every value that's optional to figure out if it's needs to go into the search criteria. If only there were a special query value that mongo ignored in queries. Then my code could look like this:
def findUsers(firstName=<ignored by mongo>, lastName=<ignored by mongo>, age=<ignored by mongo>):
query = users.find({'firstName':firstName, 'lastName':lastName, 'age':age})
return query
Now isn't that so much cleaner than before, especially if you have many more optional parameters. Any parameters that aren't specified default to something mongo just ignores. Is there any way to do this? Or at-least something more concise than what I currently have?
You're probably better off filtering your empty values in Python. You don't need a separate if-statement for each of your values. The local variables can be accessed by locals(), so you can create a dictionary by filtering out all keys with None value.
def findUsers(firstName=None, lastName=None, age=None):
loc = locals()
criteria = {k:loc[k] for k in loc if loc[k] != None}
query = users.find(criteria)
Note that this syntax uses dictionary comprehensions, introduced in Python 2.7. If you're running an earlier version of Python, you need to replace that one line with
criteria = dict((k, loc[k]) for k in loc if loc[k] != None)
I have not clearly issue during query using two criterials like Id and Other. I use a Repository storing some data like id,iso,value. I have created an index("_id","Iso") to performs queries but queries are only returning my cursor if i use only one criterial like _id, but is returning nothing if a use two (_id, Iso) (commented code).
Are the index affecting the response or the query method are failing?
use :v1.6.5 and C# official.
Sample.
//Getting Data
public List<BsonObject> Get_object(string ID, string Iso)
{
using (var helper = BsonHelper.Create())
{
//helper.Db.Repository.EnsureIndex("_Id","Iso");
var query = Query.EQ("_Id", ID);
//if (!String.IsNullOrEmpty(Iso))
// query = Query.And(query, Query.EQ("Iso", Iso));
var cursor = helper.Db.Repository.FindAs<BsonObject>(query);
return cursor.ToList();
}
}
Data:
{
"_id": "2345019",
"Iso": "UK",
"Data": "Some data"
}
After that I have Updated my data using Update.Set() methods. I can see the changed data using MongoView. The new data are correct but the query is always returning the sames olds values. To see these values i use a page that can eventually cached, but if add a timestamp at end are not changing anything, page is always returning the same olds data. Your comments are welcome, thanks.
I do not recall offhand how the C# driver creates indexes, but the shell command for creating an index is like this:
db.things.ensureIndex({j:1});
Notice the '1' which is like saying 'true'.
In your code, you have:
helper.Db.Repository.EnsureIndex("_Id","Iso");
Perhaps it should be:
helper.Db.Repository.EnsureIndex("_Id", 1);
helper.Db.Repository.EnsureIndex("Iso", 1);
It could also be related to the fact that you are creating indexes on "_Id" and the actual id field is called "_id" ... MongoDB is case sensitive.
Have a quick look through the index documentation: http://www.mongodb.org/display/DOCS/Indexes