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: http://oit.cmc.msu.ru/php/function.yaz-search.html
Дата изменения: Sun Feb 3 22:58:12 2002 Дата индексирования: Mon Oct 1 21:27:42 2012 Кодировка: |
yaz_search() prepares for a search on the target with given id. The type represents the query type - only "rpn" is supported now in which case the third argument specifies a Type-1 query (RPN). Like yaz_connect() this function is non-blocking and only prepares for a search to be executed later when yaz_wait() is called.
The RPN query is a textual represenation of the Type-1 query as defined by the Z39.50 standard. However, in the text representation as used by YAZ a prefix notation is used, that is the operater precedes the operands. The query string is a sequence of tokens where white space is ignored is ignored unless surrounded by double quotes. Tokens beginning with an at-character (@) are considered operators, otherwise they are treated as search terms.
Table 1. RPN Operators
| Syntax | Description |
|---|---|
| @and query1 query2 | intersection of query1 and query2 |
| @or query1 query2 | union of query1 and query2 |
| @not query1 query2 | query1 and not query2 |
| @set name | result set reference |
| @attrset set query | specifies attribute-set for query. This construction is only allowed once - in the beginning of the whole query |
| @attr set type=value query | applies attribute to query. The type and value are integers specifying the attribute-type and attribute-value respectively. The set, if given, specifies the attribute-set. |