Basic Commands (continued)

Learn More #3: Logical Operators:

1. The OR operator is used to retrieve terms that are synonyms or equivalents. For example, the retrieval of INTERNET OR WORLD(w)WIDE(w)WEB consists of all records containing one or both of these terms.
   
   OR increases the number of records retrieved-in other words, with OR you always get mORe. If more than one of the terms occurs within a given record, the retrieved set includes the record only once.
   
   
   Example:
   select protect? OR shield?
   
   
   
   
2. The AND operator retrieves records where two or more search terms or groups of search terms occur in the same record.
   
   SELECT INTRANET AND PRODUCTIVITY retrieves only those records containing all of these words. AND decreases the number of records retrieved since it requires each term to be present for retrieval.
   
   
   Example:
   select spider? AND updat?
   
   
   
   
3. The NOT operator prevents records that include unacceptable or irrelevant search terms from being retrieved.
   
   The expression ARCHITECTURE NOT BUILDING retrieves records that contain the term ARCHITECTURE but excludes those records that also contain the term BUILDING.
   
   
   Example:
   select eclipse? not solar
   
   

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