Database Module

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This module contains XQuery Functions to list and open databases, explicitly apply available index structures, or get information on the database structure. All functions are introduced with the db: prefix, which is linked to the http://www.basex.org/db namespace.

db:system

Signatures db:system() as xs:string
Summary Prints information about the database system, including the database path and current database settings.

db:list

Signatures db:list() as xs:string*
db:list($path as xs:string) as xs:string* Version 6.7
Summary Returns an xs:string sequence with the names of all databases. If an argument is specified, all documents of the specified database or database path are returned.

db:open

Signatures db:open($name as xs:string) as document-node()*
Summary Returns a sequence with all document nodes contained in the database specified by $name. The name of the database may be extended by a collection path.
Errors BASX0003 is raised if the database is not found.
Examples
  • db:open("docs") returns all documents from the database named docs.
  • db:open("docs/one") returns all documents from the database named docs in the subpath one.

db:open-pre

Signatures db:open-pre($name as xs:string, $pre as xs:integer) as node()
Summary Opens the database specified by $name and returns the node with the specified $pre value.
Errors BASX0004 is raised if the specified $pre value does not exist in the database.
Examples
  • db:open-pre("docs", 0) returns the first database node from the database named docs.

db:open-id

Signatures db:open-id($name as xs:string, $id as xs:integer) as node()
Summary Opens the database specified by $name and returns the node with the specified $id value.
In contrast to the pre value, the id will remain valid after update operations.
Errors BASX0004 is raised if the specified $id does not exist in the database.

db:node-pre

Signatures db:node-pre($nodes as node()*) as xs:integer*
Summary Returns the pre values of all database nodes specified by $nodes. pre values are direct, internal pointers to database nodes, which might be changed by updates.
Examples
  • db:node-pre(doc("input")) returns 0 if the database input contains a single document.

db:node-id

Signatures db:node-id($nodes as node()*) as xs:integer*
Summary Returns the id values of all database nodes specified by $nodes. id values are pointers to database nodes, which are not changed by updates.

db:text

Signatures db:text($string as item()) as text()* Version < 6.7
db:text($name as xs:string, $string as item()) as text()* Version 6.7
Summary Returns all text nodes from the text index that have $string as their string value.
Errors BASX0001 is raised if the index is not available.
BASX0002 is raised if the context item does not represent a database node. Version < 6.7
Examples
  • db:text("DB", "QUERY")/.. returns the parents of all text nodes of the database DB that match the string QUERY.

db:attribute

Signatures db:attribute($string as item()) as attribute()* Version < 6.7
db:attribute($string as item(), $attname as xs:string) as attribute()* Version < 6.7
db:attribute($name as xs:string, $string as item()) as attribute()* Version 6.7
db:attribute($name as xs:string, $string as item(), $attname as xs:string) as attribute()* Version 6.7
Summary Returns all attribute nodes from the attribute index that have $string as their string value.
If $attname is specified, the resulting attribute nodes are filtered by their attribute name.
Errors BASX0001 is raised if the index is not available.
BASX0002 is raised if the context item does not represent a database node. Version < 6.7
Examples
  • db:attribute("DB", "QUERY", "id")/.. returns the parents of all id attribute nodes of the database DB that have QUERY as string value.

db:fulltext

Signatures db:fulltext($text as xs:string) as text() Version < 6.7
db:fulltext($name as xs:string, $text as xs:string) as text() Version 6.7
Summary Returns all text nodes from the full-text index that contain the string $text. The index full-text options are used for searching, i.e., if the index terms have been stemmed, the search string will be stemmed as well.
Errors BASX0001 is raised if the index is not available.
BASX0002 is raised if the context item does not represent a database node. Version < 6.7
Examples
  • db:fulltext("DB", "QUERY") returns all text nodes of the database DB that contain the string QUERY.

db:info

Signatures db:info() as xs:string
db:info($type as xs:string) as xs:string Version < 6.7
db:info($name as xs:string) as xs:string Version 6.7
db:info($name as xs:string, $type as xs:string) as xs:string Version 6.7
Summary Returns information on the database that is referenced by the current context item. Version < 6.7
Without arguments, returns information about the database system, including the database path and current database settings (equivalent to db:system()).
If $name is specified, returns information on the specified database.
If $type is specified, the function returns information on a database index. It must be one of the values TEXT, ATTRIBUTE, FULLTEXT, PATH, TAG, or ATTNAME.
Errors BASX0001 is raised if the specified index is not available.
BASX0002 is raised if the context item does not represent a database node. Version < 6.7