Databases

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(Create/Drop Database)
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Database must follow the [[Valid Names|valid names constraints]].
Database must follow the [[Valid Names|valid names constraints]].
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=Manage Resources=
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=Access Resources=
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Stored resources and external documents can be accessed in different ways:
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==XML Documents==
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{{Mark|Updated with Version 7.2.1:}}
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Various XQuery functions exist to access XML documents in databases and from other locations:
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* {{Mono|db:open("dbname", "PATH/TO/DOCS")}}: returns documents that are found in the specified database at the specified (optional) path.
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* {{Mono|collection("PATH/TO/DOCS")}}: returns all documents that are found at the location {{Mono|TO/DOCS}} in the database {{Mono|PATH}}. If the addressed database does not exist, or if the argument does not start with a valid database name, the string is interpreted as URI reference, and the documents found at this location will be returned.
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* {{Mono|doc("PATH/TO/DOC.XML")}}: returns the document found at the location {{Mono|TO/DOC.XML}} in the database {{Mono|PATH}}. If the addressed database does not exist, or if the argument does not start with a valid database name, the string is interpreted as URI reference, and the document found at this location will be returned.
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The {{Mono|fn:document-uri()}} and {{Mono|fn:base-uri()}} functions returns paths that can be reused as arguments for the {{Mono|fn:doc()}} and {{Mono|fn:collection()}} functions.
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==Raw Files==
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* XQuery: <code>db:retrieve("dbname", "path/to/docs")</code> returns raw files in their Base64 representation. By choosing <code>"method=raw"</code> as [[Serialization|Serialization Option]], the data is returned in its original byte representation:
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<pre class="brush:xquery">
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declare option output:method "raw";
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db:retrieve('multimedia', 'sample.avi')
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</pre>
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* Commands: <code>[[Commands#RETRIEVE|RETRIEVE]]</code> returns raw files without modifications.
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==HTTP Services==
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* With [[REST]] and [[WebDAV]], all database resources can be requested in a uniform way, no matter if they are well-formed XML documents or binary files.
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=Update Resources=
Once you have created a database, additional commands exist to modify its contents:
Once you have created a database, additional commands exist to modify its contents:
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Last but not least, XML documents can also be added via the GUI and the ''Database'' menu.
Last but not least, XML documents can also be added via the GUI and the ''Database'' menu.
-
 
-
=Access Resources=
 
-
 
-
Stored resources and external documents can be accessed in different ways:
 
-
 
-
==XML Documents==
 
-
 
-
{{Mark|Updated with Version 7.2.1:}}
 
-
 
-
Various XQuery functions exist to access XML documents in databases and from other locations:
 
-
 
-
* {{Mono|db:open("dbname", "PATH/TO/DOCS")}}: returns documents that are found in the specified database at the specified (optional) path.
 
-
* {{Mono|collection("PATH/TO/DOCS")}}: returns all documents that are found at the location {{Mono|TO/DOCS}} in the database {{Mono|PATH}}. If the addressed database does not exist, or if the argument does not start with a valid database name, the string is interpreted as URI reference, and the documents found at this location will be returned.
 
-
* {{Mono|doc("PATH/TO/DOC.XML")}}: returns the document found at the location {{Mono|TO/DOC.XML}} in the database {{Mono|PATH}}. If the addressed database does not exist, or if the argument does not start with a valid database name, the string is interpreted as URI reference, and the document found at this location will be returned.
 
-
 
-
The {{Mono|fn:document-uri()}} and {{Mono|fn:base-uri()}} functions returns paths that can be reused as arguments for the {{Mono|fn:doc()}} and {{Mono|fn:collection()}} functions.
 
-
 
-
==Raw Files==
 
-
 
-
* XQuery: <code>db:retrieve("dbname", "path/to/docs")</code> returns raw files in their Base64 representation. By choosing <code>"method=raw"</code> as [[Serialization|Serialization Option]], the data is returned in its original byte representation:
 
-
 
-
<pre class="brush:xquery">
 
-
declare option output:method "raw";
 
-
db:retrieve('multimedia', 'sample.avi')
 
-
</pre>
 
-
 
-
* Commands: <code>[[Commands#RETRIEVE|RETRIEVE]]</code> returns raw files without modifications.
 
-
 
-
==HTTP Services==
 
-
 
-
* With [[REST]] and [[WebDAV]], all database resources can be requested in a uniform way, no matter if they are well-formed XML documents or binary files.
 
=Export Data=
=Export Data=

Revision as of 21:52, 25 April 2012

This page is part of the Getting Started Section.

In BaseX, a single database contains an arbitrary number of resources, addressed by their unique database path. Since Version 7.0, resources can either be XML documents or raw files (binaries). Sets of XML documents are also called collections. Some information on binary data can be found on an extra page.

Contents

Create/Drop Database

New databases can either be created in the GUI, on command line, or using any of our APIs. XML documents can be specified along with the create operation, which will be added to the database in a bulk operation:

Various parsers can be chosen to influence the database creation, or to convert different formats to XML.

Existing databases can eventually be dropped again:

Database must follow the valid names constraints.

Access Resources

Stored resources and external documents can be accessed in different ways:

XML Documents

Updated with Version 7.2.1:

Various XQuery functions exist to access XML documents in databases and from other locations:

The fn:document-uri() and fn:base-uri() functions returns paths that can be reused as arguments for the fn:doc() and fn:collection() functions.

Raw Files

declare option output:method "raw";
db:retrieve('multimedia', 'sample.avi')

HTTP Services

Update Resources

Once you have created a database, additional commands exist to modify its contents:

The AUTOFLUSH option can be turned off before bulk operations (i.e. before a large number of new resources is added to the database).

The following commands create an empty database, add two resources, explicitly flush data structures to disk, and finally delete all inserted data:

CREATE DB example
SET AUTOFLUSH false
ADD example.xml
ADD ...
STORE TO images/ 123.jpg
FLUSH
DELETE /

You may as well use the BaseX-specific XQuery Database Functions to add, replace and delete XML documents:

let $root := "/path/to/xml/documents/"
for $file in file:list($root)
return db:add("database", $root || $file)

Last but not least, XML documents can also be added via the GUI and the Database menu.

Export Data

All resources stored in a database can be exported, i.e., written back to disk. This can be done in several ways:

Changelog

Version 7.2.1

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