Query DSL

Domain Specific Language for document search

Invariant Content Insight uses Elasticsearch engine for storage and the content search module makes use of Elasticsearch Query DSL

The query string (search_text parameter) passed to the engine is parsed into a series of terms and operators. A term can be a single word — tasty or chicken — or a phrase, surrounded by double quotes — "tasty chicken" — which searches for all the words in the phrase, in the same order.

The search can be customized using operators listed below.

Wildcards

Wildcard searches can be run on individual terms, using ? to replace a single character, and * to replace zero or more characters. Wildcard searches are not efficient and their use should be limited.

Boolean operators

By default, all terms are optional, as long as one term matches. A search for fish frog turtle will find any document that contains one or more of fish or frog or turtle. There are also boolean operators which can be used in the query string itself to provide more control.

The preferred operators are + (this term must be present) and - (this term must not be present). All other terms are optional.

For example, in the following query:

wise fishes +monkey -tortoise
·       monkey must be present
·       tortoise must not be present
·       wise and fishes are optional — their presence increases the search relevance

The familiar operators AND, OR and NOT (also written &&, || and !) are also supported. However, you have to keep the precedence in mind when using these. NOT takes precedence over AND, which takes precedence over OR.

The operators + and - only affect the term to the right of the operator. AND and OR operators can affect the terms to the left and right.

Grouping

Multiple terms or clauses can be grouped together with parentheses to form sub-queries:

(smart OR hungry) AND bears