# Exclude empty-string, null and non-existant
**URL:** https://discuss.elastic.co/t/exclude-empty-string-null-and-non-existant/181140
**Category:** Elasticsearch
**Created:** [May 15, 2019, 9:50am UTC](https://discuss.elastic.co/t/exclude-empty-string-null-and-non-existant/181140 "2019-05-15T09:50:38Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@Pictor](https://discuss.elastic.co/u/Pictor)
#### Post date: [May 15, 2019, 9:50am UTC](https://discuss.elastic.co/t/exclude-empty-string-null-and-non-existant/181140/1 "2019-05-15T09:50:38Z")
How does one query for all documents having a field with non empty value? (aka _mandatory_ value)
I can exclude the `null` values or non existing fields via the `exists` (negated) query, but I also need to ensure that the values is **not an empty string**.
From what I know an _empty_ string is a non-`null` value, so it will be included in results from `exists` query.
What's the best (smartest & most performant) way to do this filtering?
- could use a script to check for the property `field.length > 0`, but I don't like to rely on scripting languages in my queries (if not strictly needed); also I suppose is not ideal for performances.
- could use a `"wildcard": { "fieldname": "?*" }` together with the `must exists` query. It's the solution I am using at the moment but, still, I believe there must be some better performing way than using regular expressions.
- could _maybe (?)_ use some parameter for the `exists` query so that also empty strings are treated as `null`/non-existing value.
**What I want to achieve is to treat _empty-string_, `null` and _non-existing_ as the same (kind of "invalid value").**
Also, an additional/optional curiosity is if it makes sense (and how) to do a `trim` of the field value, to exclude strings like `" "`.
I was using the `missing` query for the opposite case (empty field).
Is it completely deprecated? Should I always use the `must_not`-`exists` query instead?
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### Author:  [@Pictor](https://discuss.elastic.co/u/Pictor)
#### Post date: [May 15, 2019, 7:36pm UTC](https://discuss.elastic.co/t/exclude-empty-string-null-and-non-existant/181140/2 "2019-05-15T19:36:20Z")
Looks like using `"wildcard": { "fieldname": "?*" }` is the best solution at the moment.
But I am not sure how it scales when the `wildcard`+`exists` check is performed on more than one field.
Not sure how much could it slow down the search.
Please, could anybody with solid experience enlighten me?
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [June 12, 2019, 7:36pm UTC](https://discuss.elastic.co/t/exclude-empty-string-null-and-non-existant/181140/3 "2019-06-12T19:36:23Z")
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