Query Language

Query Language: general concepts

Concept Syntax Example/Comments
Term: find occurrences of a specific term Term itself. Not case sensitive. Wildcards: appending a '*' at the end of a term will match zero or more letters.
Phrase: find occurrences of a sequence of terms Separate terms with a space, and enclose in double quote character ("). Omitting quotes will do a sloppy phrase search (where supported by native resource). "heart lung transplant" will search for an exact sequence of these terms (and so will match “heart/lung transplant”, “heart-lung transplant” or “heart lung transplant”
heart lung transplant (without quotes) will match these words in any order (on supporting resources).
The default (where no field is specified) is to search for a term/phrase (plus spelling variants) across a fields.
Field: find occurrences of a value within a specific field (eg. title, author) Field “dot” value
(Adding a dollar sign ($) to the field name will enable stemming, which uses over 30 spelling rules to match plurals, superlatives, tense and other spelling variations)		 title."intravenous salbutamol" will search for occurrences of the phrase “intravenous salbutamol” in the titles of documents.
'OR' Boolean Operator: find occurrences of any of the listed expressions Separate list of expressions with OR reserved word or a semicolon Example 1:
heart lung transplant; heart transplant
Example 2:
title.nebulised salbutamol OR title.intravenous salbutamol
'+' Operator: find occurrences that MUST be present in documents Prepend a plus (‘+’) to required expressions intravenous salbutamol; +author.phung finds documents that MUST be authored by “Phung”, but ranks those that contain “intravenous salbutamol” ahead of those that do not.
'AND' Boolean Operator Separate each subexpression with “AND” intravenous salbutamol, +author.phung finds documents that MUST be both authored by “Phung” AND contain “intravenous salbutamol”. This is equivalent to: +intravenous salbutamol, +author.phung
Order of precendence: default (left-right):
space (‘ ‘)
> dot (‘.’)
> plus (‘+’)/AND
> semicolon/OR 		Expressions contained in parentheses ‘(‘..’)’ are evaluated first from inside-out (salbutamol; corticosteroids) AND asthma finds the union of “salbutamol OR corticosteroids” first before intersecting the union with “asthma”.

Query Language: special restrictions

  1. Not all fields are supported across all knowledge resources. The fields available and level of support are provided on the Search Fields information page.
  2. The full query language is not supported on Micromedex. Specifically only simple searches consisting of one or more terms are supported. The results returned in Micromedex is the intersection of all these terms (ie: only documents containing ALL terms are returned).
  3. Wildcards: STAT!Ref does not support Wildcard searches. Using wildcards with only a small number of letters (eg. a*) will match many documents and can be very slow. It is recommended at least 4 letters be used. Stemmed fields (where a '$' is appended to the field name) perform wildcard comparisons AFTER stemming has been performed.