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# yaz_search

(PHP 4 >= 4.0.1)

yaz_search -- Prepares for a search

## Description

int yaz_search ( int id, string type, string query)

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

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.

Tabelle 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.

Beispiel 1. Query Examples

Query

    computer

matches documents where "computer" occur. No attributes are specified.

The Query

    "donald knuth"

matches documents where "donald knuth" occur.

For the query

    @attr 1=4 art

attribute type is 1 (Bib-1 use), attribute value is 4 Title), so this should match documents where `art` occur in the title.

Another more complex one:

    @attrset gils @and @attr 1=4 art @attr 1=1003 "donald knuth"

The query as a whole uses the GILS attributeset. The query matches documents where `art` occur in the title and in which `donald knuth` occur in the author.

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