Semantic MediaWiki/data/smw di blob: Difference between revisions
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* '''Purpose''': specifications for all SMW Objects that are text-blobs (i.e. long text which cannot be associated with a wiki page) | * '''Purpose''': specifications for all SMW Objects that are text-blobs (i.e. long text which cannot be associated with a wiki page) | ||
* '''Refers to''': {{l/same|smw_object_ids}} | * '''Refers to''': {{l/same|smw_object_ids}} | ||
==Fields== | |||
* '''s_id''': ID of wiki page on which the property appears | |||
* '''p_id''': ID of wiki page for the property name | |||
* '''o_blob''': value when text is too long for <code>o_hash</code>; otherwise NULL | |||
* '''o_hash''': exact value of text if <code>o_blob</code> is null; otherwise, truncated value with hash appended (purpose unclear) | |||
==SQL== | ==SQL== | ||
<syntaxhighlight lang=mysql> | <syntaxhighlight lang=mysql> | ||
| Line 14: | Line 19: | ||
</syntaxhighlight> | </syntaxhighlight> | ||
===Example=== | ===Example=== | ||
====titles==== | |||
<syntaxhighlight lang=mysql> | |||
SELECT | |||
s_id, | |||
s.smw_namespace AS s_namespace, | |||
CAST(s.smw_title AS CHAR) AS s_title | |||
FROM | |||
(smw_di_blob AS r | |||
LEFT JOIN smw_object_ids AS s ON r.s_id = s.smw_id) | |||
</syntaxhighlight> | |||
* Filter for <code>p_id</code> to get pages that use a specific property. | |||
* Filter for <code>p_id</code> and <code>o_hash</code> to find pages where a specific property has a specific text value. | |||
* Note that this table only applies to property values that do not link to wiki pages; see {{l/same|smw_di_wikipage}} for those that do. | |||
====relations==== | |||
<syntaxhighlight lang=mysql> | <syntaxhighlight lang=mysql> | ||
SELECT s_id, p_id | SELECT s_id, p_id | ||
Latest revision as of 12:04, 2 February 2018
About
- Purpose: specifications for all SMW Objects that are text-blobs (i.e. long text which cannot be associated with a wiki page)
- Refers to: smw_object_ids
Fields
- s_id: ID of wiki page on which the property appears
- p_id: ID of wiki page for the property name
- o_blob: value when text is too long for
o_hash; otherwise NULL - o_hash: exact value of text if
o_blobis null; otherwise, truncated value with hash appended (purpose unclear)
SQL
CREATE TABLE `smw_di_blob` (
`s_id` int(8) unsigned NOT NULL,
`p_id` int(8) unsigned NOT NULL,
`o_blob` mediumblob,
`o_hash` varbinary(255) DEFAULT NULL,
KEY `s_id` (`s_id`,`p_id`),
KEY `p_id` (`p_id`,`o_hash`)
) ENGINE=InnoDB DEFAULT CHARSET=binary
Example
titles
SELECT
s_id,
s.smw_namespace AS s_namespace,
CAST(s.smw_title AS CHAR) AS s_title
FROM
(smw_di_blob AS r
LEFT JOIN smw_object_ids AS s ON r.s_id = s.smw_id)
- Filter for
p_idto get pages that use a specific property. - Filter for
p_idando_hashto find pages where a specific property has a specific text value. - Note that this table only applies to property values that do not link to wiki pages; see smw_di_wikipage for those that do.
relations
SELECT s_id, p_id
, s.smw_namespace AS s_namespace
, CAST(s.smw_title AS char) AS s_title
, p.smw_namespace AS p_namespace
, CAST(p.smw_title AS char) AS p_title
, CAST(o_blob AS CHAR) as text
, CAST(o_hash AS CHAR) as hash
FROM
(smw_di_blob AS r
LEFT JOIN smw_object_ids AS s ON r.s_id=s.smw_id)
LEFT JOIN smw_object_ids AS p ON r.p_id=p.smw_id
ORDER BY s_id
- p_namespace will probably always be the "property:" namespace, which defaults to 102 (unless there's some way to use a page outside that namespace as a property)
