Patent US 5,708,804

A data processing device and method for searching a database having a plurality of entries to locate entries which match a search string. Each entry within the database is arranged into one or more predetermined search fields which each contain a character string. In response to receipt of a search string, a determination is made whether the search string is a subset of a particular entry within the database. In response to the determination that the search string is a subset of a particular entry, the particular entry is recorded as a matching entry. However, in response to a determination that the search string is not a subset of a particular entry, a determination is made whether a modified search string formed by removing delimiters from the search string is a subset of a character string within a particular predetermined search field within the particular entry. In response to a determination that the modified search string is a subset of the character string, the particular entry is recorded as a matching entry. Thereafter, the foregoing steps are repeated for each of the number of entries within the database such that matching entries within the database are efficiently located.