Boolean Operators Proximity Operators and Operator
Precedence
Use the Boolean AND, OR, NOT
operators in the Words and
Phrases, Title, and Company fields.
AND Operator - back to top
Use AND to require multiple terms to
be found in an article.
For Example: Searching for ginko and ginseng in the Words and Phrases field will retrieve only articles that include both terms.
OR Operator - back to top
Use OR to
find alternate terms in a search statement.
For Example: Searching for ginko or ginseng will retrieve articles which include at least one of the terms, but not necessarily both terms.
NOT Operator - back to top
Use NOT to exclude words from a search
statement.
For Example: Searching for java not coffee will limit the search to articles that include the word java but not those that include the word coffee.
Proximity Operators - back to top
Using Parentheses
Use PARENTHESES to group or override normal
term precedence.
For Example: Searching for ginseng and (herbal or homeopathic) will retrieve articles that include ginseng and either herbal or homeopathic. (With out the parentheses the example above would have resulted in articles that include both ginseng and herbal OR those that included homeopathic.)
Using the NEAR Operator
- back to top
The NEAR operator searches terms that occur within a
specified number of words of each other regardless of order. The second term may appear in
the text prior to the first term. Stop words can exist between the two search terms.
For example, home near banking will retrieve articles in which the terms home appears either prior to or after the word banking.
Operator Precedence
- back to top
Boolean queries involving mixed operators are evaluated
using standard Boolean precedence rules. For example in a query containing both OR
and AND operators, all of the AND operators are
evaluated before any of the OR operators are evaluated. The table which
follows lists the precedence of each of the search operators. Operators with higher
precedence are evaluated before operators with lower precedence. If you mix operators with
the same precedence, for example AND and NOT, they are
evaluated left-to-right. You may use parenthesis to override this precedence and specify
the order of evaluation. For example, in the query (General Motors OR Ford) AND
automobile, the OR will be evaluated first.
| HIGHEST | CT= (any specified two character prefix term equals) |
| ( ) Parentheses | |
| NEAR Proximity | |
| NOT | |
| AND | |
| LOWEST | OR |
The table below summarizes the Boolean functionality - back to top
| OPERATOR | ACTION |
| and | Finds only documents containing all of the specified words. The search price AND copper finds documents with both the word price and the word copper. |
| or | Finds only documents containing at least one of the specified words or phrases. The search price OR copper finds documents with either the word price or the word copper. The found documents may contain more than one of the specified terms, but do not have to have both. |
| not | Excludes documents containing the specified word or phrase. The search copper NOT steel finds documents with copper but not those that also contain the word steel. NOT cannot be used as a unary operator, that is queries that are entered as NOT steel are not supported. |
| ( ) | Parentheses are used to group terms or to override normal term precedence. For example, price and (copper or steel) finds articles that include the term price and either copper or steel. |
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