# Help constructing .NET NEST query **URL:** \ **Category:** Elasticsearch\ **Created:** [October 17, 2018, 6:24am UTC](https://discuss.elastic.co/t/help-constructing-net-nest-query/152762 "2018-10-17T06:24:54Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![rpm1984](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/rpm1984/32/36595_2.png) [@rpm1984](https://discuss.elastic.co/u/rpm1984)\ **Post date:** [October 17, 2018, 6:24am UTC](https://discuss.elastic.co/t/help-constructing-net-nest-query/152762/1 "2018-10-17T06:24:54Z")
Hi there, I'm using the NEST .NET client (6.3.1), and trying to compose a search query that is based on a number of (optional) parameters. Here's what i've got so far: ``` var searchResponse = await _client.SearchAsync(s => s .Query(qq => { var filters = new List(); if (filter.CategoryType.HasValue) { filters.Add(qq.Term(p => p.CategoryType, filter.CategoryType.Value)); } if (filter.StatusType.HasValue) { filters.Add(qq.Term(p => p.StatusType, filter.StatusType.Value)); } if (!string.IsNullOrWhiteSpace(filter.Suburb)) { filters.Add(qq.Term(p => p.Suburb, filter.Suburb)); } return ?????; // what do i do her? }) ); ``` `filter` is an object with a bunch of nullable properties. So, whatever has a value i want to add as a match query. So, to achieve that i'm trying to build up a list of `QueryContainer`'s (not sure that's the right way), but struggling to figure out how to return that as a list of AND predicates. Any ideas? Thanks ---
**Author:** ![forloop](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/forloop/32/9021_2.png) [@forloop](https://discuss.elastic.co/u/forloop)\ **Post date:** [October 22, 2018, 2:41am UTC](https://discuss.elastic.co/t/help-constructing-net-nest-query/152762/2 "2018-10-22T02:41:43Z")
What you're essentially trying to do is combine multiple queries together, where each query would run in a filter clause. The `bool` query is a compound query that can be used for this purpose, and the queries can be added as `filter` clauses. Take a look at the documentation on [writing `bool` queries with NEST](https://www.elastic.co/guide/en/elasticsearch/client/net-api/current/bool-queries.html), as NEST overloads operators for query types to allow them to be easily combined with `&&`, `||`, and to run in a filter context with `+` unary operator. Another feature of NEST that helps out here is the notion of conditionless queries; if the input to a query is determined to be conditionless i.e. a `null` or `empty` string for example, then NEST will omit the query altogether from the request. This means that you don't need to check whether each `filter` property is `null` before adding to the set of filters, NEST will perform this filtering by default. ---
**Author:** ![rpm1984](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/rpm1984/32/36595_2.png) [@rpm1984](https://discuss.elastic.co/u/rpm1984)\ **Post date:** [October 22, 2018, 5:24am UTC](https://discuss.elastic.co/t/help-constructing-net-nest-query/152762/3 "2018-10-22T05:24:27Z")
Hey Russ, thanks for your reply. Great tips. I _almost_ got it working. Here's my code: ``` var searchResponse = _client.Search(s => s .Query(q => q .Bool(b => b .Must( bs => bs.Terms(p => p.Field(f => f.ListingId) .Terms(filter.ListingIds)), bs => bs.Term(p => p.Category, filter.Category), bs => bs.Term(p => p.Status, filter.Status), bs => bs.Term(p => p.Suburb, filter.Suburb), bs => bs.DateRange(p => p.Field(f => f.SoldOrLeasedOn) .GreaterThanOrEquals(filter.SoldOrLeasedAfter)), bs => bs.Range(p => p.Field(f => f.Price) .GreaterThanOrEquals(filter.MinPrice) .LessThanOrEquals(filter.MaxPrice)), bs => bs.GeoBoundingBox(p => p.Field(f => f.LatLong) .BoundingBox(filter.BoundingBox.TopLeft.Lat, filter.BoundingBox.TopLeft.Long, filter.BoundingBox.BottomRight.Lat, filter.BoundingBox.BottomRight.Long)) ) ) ) ); ``` So it worked, with the exception of the .GeoBoundingBox part. `filter.BoundingBox` is a sub-class, so that falls over if it's null. So i'd need to check for the existence here. As soon as you introduce a conditional aspect here, can't use the Fluent DSL, right? ---
**Author:** ![forloop](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/forloop/32/9021_2.png) [@forloop](https://discuss.elastic.co/u/forloop)\ **Post date:** [October 22, 2018, 5:46am UTC](https://discuss.elastic.co/t/help-constructing-net-nest-query/152762/4 "2018-10-22T05:46:29Z")
Please could you format your code, using `` icon as explained in [this guide](https://discuss.elastic.co/t/about-the-elasticsearch-category/21). It will make your post more readable! You can also use markdown style like: ```` ``` CODE ``` ```` This is the icon to use if you are not using markdown format: ![image](https://us1.discourse-cdn.com/elastic/original/3X/7/e/7e6e239431ec2d71cbf1beef741f2e93e7cc762c.jpg) ---
**Author:** ![rpm1984](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/rpm1984/32/36595_2.png) [@rpm1984](https://discuss.elastic.co/u/rpm1984)\ **Post date:** [October 22, 2018, 6:02am UTC](https://discuss.elastic.co/t/help-constructing-net-nest-query/152762/5 "2018-10-22T06:02:46Z")
Sorry. 😊 Updated. ---
**Author:** ![forloop](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/forloop/32/9021_2.png) [@forloop](https://discuss.elastic.co/u/forloop)\ **Post date:** [October 22, 2018, 6:26am UTC](https://discuss.elastic.co/t/help-constructing-net-nest-query/152762/6 "2018-10-22T06:26:07Z")
You can convert the expression to a method group, and return `null` if the condition isn't met. For example, ```auto var searchResponse = _client.Search(s => s .Query(q => q .Bool(b => b .Must( bs => bs.Terms(p => p.Field(f => f.ListingId) .Terms(filter.ListingIds)), bs => bs.Term(p => p.Category, filter.Category), bs => bs.Term(p => p.Status, filter.Status), bs => bs.Term(p => p.Suburb, filter.Suburb), bs => bs.DateRange(p => p.Field(f => f.SoldOrLeasedOn) .GreaterThanOrEquals(filter.SoldOrLeasedAfter)), bs => bs.Range(p => p.Field(f => f.Price) .GreaterThanOrEquals(filter.MinPrice) .LessThanOrEquals(filter.MaxPrice)), bs => { // if bounding box is null, don't filter on it if (filter.BoundingBox == null) { return null; } return bs.GeoBoundingBox(p => p .Field(f => f.LatLong) .BoundingBox( filter.BoundingBox.TopLeft.Lat, filter.BoundingBox.TopLeft.Long, filter.BoundingBox.BottomRight.Lat, filter.BoundingBox.BottomRight.Long) ); } ) ) ); ``` You can also refactor it out into a separate method that accepts a `QueryContainerDescriptor` and returns a `QueryContainer`. ---
**Author:** ![rpm1984](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/rpm1984/32/36595_2.png) [@rpm1984](https://discuss.elastic.co/u/rpm1984)\ **Post date:** [October 22, 2018, 10:24pm UTC](https://discuss.elastic.co/t/help-constructing-net-nest-query/152762/7 "2018-10-22T22:24:39Z")
Ah perfect, of course! Thanks Russ 🙂 ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [November 19, 2018, 10:36pm UTC](https://discuss.elastic.co/t/help-constructing-net-nest-query/152762/8 "2018-11-19T22:36:24Z")
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