Fulltext functions

AQL offers the following functions to filter data based on fulltext indexes.

FULLTEXT()

FULLTEXT(coll, attribute, query, limit) → docArray

Return all documents from collection coll, for which the attribute attribute matches the fulltext search phrase query, optionally capped to limit results.

Note: the FULLTEXT() function requires the collection coll to have a fulltext index on attribute. If no fulltext index is available, this function will fail with an error at runtime. It doesn’t fail when explaining the query however.

• coll (collection): a collection
• attribute (string): the attribute name of the attribute to search in
• query (string): a fulltext search expression as described below
• limit (number, optional): if set to a non-zero value, it will cap the result to at most this number of documents
• returns docArray (array): an array of documents

FULLTEXT() is not meant to be used as an argument to FILTER, but rather to be used as the expression of a FOR statement:

FOR oneMail IN FULLTEXT(emails, "body", "banana,-apple")
    RETURN oneMail._id

query is a comma-separated list of sought words (or prefixes of sought words). To distinguish between prefix searches and complete-match searches, each word can optionally be prefixed with either the prefix: or complete: qualifier. Different qualifiers can be mixed in the same query. Not specifying a qualifier for a search word will implicitly execute a complete-match search for the given word:

• FULLTEXT(emails, "body", "banana")
  Will look for the word banana in the attribute body of the collection collection.

• FULLTEXT(emails, "body", "banana,orange")
  Will look for both words banana and orange in the mentioned attribute. Only those documents will be returned that contain both words.

• FULLTEXT(emails, "body", "prefix:head")
  Will look for documents that contain any words starting with the prefix head.

• FULLTEXT(emails, "body", "prefix:head,complete:aspirin")
  Will look for all documents that contain a word starting with the prefix head and that also contain the (complete) word aspirin. Note: specifying complete: is optional here.

• FULLTEXT(emails, "body", "prefix:cent,prefix:subst")
  Will look for all documents that contain a word starting with the prefix cent and that also contain a word starting with the prefix subst.

If multiple search words (or prefixes) are given, then by default the results will be AND-combined, meaning only the logical intersection of all searches will be returned. It is also possible to combine partial results with a logical OR, and with a logical NOT:

• FULLTEXT(emails, "body", "+this,+text,+document")
  Will return all documents that contain all the mentioned words. Note: specifying the + symbols is optional here.

• FULLTEXT(emails, "body", "banana,|apple")
  Will return all documents that contain either (or both) words banana or apple.

• FULLTEXT(emails, "body", "banana,-apple")
  Will return all documents that contain the word banana, but do not contain the word apple.

• FULLTEXT(emails, "body", "banana,pear,-cranberry")
  Will return all documents that contain both the words banana and pear, but do not contain the word cranberry.

No precedence of logical operators will be honored in a fulltext query. The query will simply be evaluated from left to right.