Viewing version details

To enable viewing different version details on the UI, you modify the serialization JSP file that retrieves data for the versions, and you also update the query template file to make the SQL queries versionable to retrieve the different version information.

In the JSP file, you modify the <wcf:getData> tag to add the context data as shown:

<wcf:contextData name="versionId" data="${param.objectVersionId}"/>

The wcf:getData tag is used to retrieve business object information. For more information about how to locate the wcf:getData tag to modify, see the instructions in step 4 of the following page: Enabling viewing custom object versions on the UI.

In the query template file, you either add a versionId parameter to the query or define a version-specific query. When version objects are displayed, some of the data must be retrieved from the version schema (data that is versioned) and other data must be retrieved from the base schema (data that is not versioned). The system can automatically adjust the queries of certain types. For other types of queries, you must write a version-specific query.

Limitations of view version SQL generation

SQL Subselect statements are not supported.
If a table is versionable, all occurrences of that table in a query must come from the version schema. For example, if there is a query with two versionable tables (CATENTRY and CATENTDESC), the version SQL generation either adds the version schema prefix to both tables (for version requests) or to neither table (not version request). This is because version SQL generation does not allow select data from the base CATENTRY table and from the version CATENTDESC table in the same query. To do this, a version-specific query is required.

Content versioning query template SQL generation

Query templates that support version SQL generation is marked with a "param=versionable" in the query template file. To retrieve the version object, the existing Get<Noun> service is used and a versionId parameter is passed in the business context area of the request. When the server detects a version request, it modifies the SQL defined in the query template to include the versionId, and select data from tables in the version schema as defined in the wc-content-version.xml configuration file.

For example, to retrieve a version of CatalogGroup 10201, a GetCatalogGroup request is sent with the specified versionId in the business context. Note that view version requests supports only one object, that is, a request can return only one version of CatalogGroup 10201. It cannot return multiple versions of the CatalogGroup 10201. Also, view version requests cannot return multiple versions for multiple objects.

Consider the following CatalogGroup associated query marked as versionable:

BEGIN_ASSOCIATION_SQL_STATEMENT
	name=IBM_RootCatalogGroupWithDescriptionWithTopCatGroup
	base_table=CATGROUP
	additional_entity_objects=true
	param=versionable	
	sql=
		SELECT 
				CATGROUP.$COLS:CATGROUP$,
				CATGRPDESC.$COLS:CATGRPDESC$,
				CATTOGRP.$COLS:CATTOGRP$
		FROM
				CATGROUP
				 LEFT OUTER JOIN
				CATGRPDESC ON 
					 (CATGROUP.CATGROUP_ID = CATGRPDESC.CATGROUP_ID AND
					  CATGRPDESC.LANGUAGE_ID IN ($CONTROL:LANGUAGES$))
				 LEFT OUTER JOIN
				CATTOGRP ON 
					(CATGROUP.CATGROUP_ID = CATTOGRP.CATGROUP_ID AND
					 (CATTOGRP.CATALOG_ID = $CTX:CATALOG_ID$ OR CATTOGRP.CATALOG_ID_LINK IS NULL))
		WHERE
                CATGROUP.CATGROUP_ID IN ($ENTITY_PKS$)
END_ASSOCIATION_SQL_STATEMENT

The following occurs when transforming a query into a version query:

Any versionable tables that are not joined are replaced by the table from the version schema. For example, the CATGROUP table is versionable and is replaced by VCW_DEMO.CATGROUP.

Any versionable tables that are joined are replaced with an alias that selects data from the versionable table and the filters the data by the specified versionId. For example, the CATGRPDESC table is versionable and the statement:

LEFT OUTER JOIN CATGRPDESC ON  (CATGROUP.CATGROUP_ID = CATGRPDESC.CATGROUP_ID AND CATGRPDESC.LANGUAGE_ID IN ($CONTROL:LANGUAGES$))

Is replaced by:

LEFT OUTER JOIN (SELECT * FROM VCW_DEMO.CATGRPDESC WHERE VCW_DEMO.CATGRPDESC.CMVERSNINFO_ID = versionId) T0 ON (VCW_DEMO.CATGROUP.CATGROUP_ID = T0.CATGROUP_ID AND T0.LANGUAGE_ID IN ($CONTROL:LANGUAGES$))

Aliases created in the preceding step are substituted back into the query. For example, the alias T0 is created for the CATGRPDESC table in the preceding example and the statement:

SELECT 
	CATGROUP.$COLS:CATGROUP$,
	CATGRPDESC.$COLS:CATGRPDESC$,
	CATTOGRP.$COLS:CATTOGRP$

Is transformed to:

SELECT 
	VCW_DEMO.CATGROUP.$COLS:CATGROUP$,
	T0.$COLS:CATGRPDESC$,
	CATTOGRP.$COLS:CATTOGRP$

Final transformed query is:

FROM
	VCW_DEMO.CATGROUP
		 LEFT OUTER JOIN (SELECT * FROM VCW_DEMO.CATGRPDESC WHERE VCW_DEMO.CATGRPDESC.CMVERSNINFO_ID = versionId) T0 ON (VCW_DEMO.CATGROUP.CATGROUP_ID = T0.CATGROUP_ID AND T0.LANGUAGE_ID IN ($CONTROL:LANGUAGES$))
		LEFT OUTER JOIN (SELECT * FROM VCW_DEMO.CATTOGRP WHERE VCW_DEMO.CATTOGRP.CMVERSNINFO_ID = versionId) T1 ON (VCW_DEMO.CATGROUP.CATGROUP_ID = T1.CATGROUP_ID AND (T1.CATALOG_ID = $CTX:CATALOG_ID$ OR T1.CATALOG_ID_LINK IS NULL)) 

WHERE
                VCW_DEMO.CATGROUP.CATGROUP_ID IN ($ENTITY_PKS$) AND VCW_DEMO.CATRGROUP.CMVERSNINFO_ID = versionId

Version-specific queries

Alternatively, version-specific queries can be constructed using the $VERSION$ and $VERSION_ID$ tags in the query template. Data service layer (DSL) replaces the $VERSION$ tag with version schema name (such as VCW_DEMO). DSL replaces the $VERSION_ID$ tab with the versionId parameter from the business context area of the request. Consider the following CatalogEntry associated query that uses $VERSION$ and $VERSION_ID$ tags:

BEGIN_XPATH_TO_SQL_STATEMENT
	name=/CatalogEntry[CatalogEntryIdentifier[(UniqueID=)]]+MyCompany_Admin_Details_Version
	base_table=CATENTRY
	className=com.ibm.commerce.catalog.facade.server.services.dataaccess.db.jdbc.EntitledCatalogEntriesSQLComposer 
	param=accessProfile_IBM_Store
	param=includeBrowseable_true
	param=psMark_AndPSAgreements	
	param=versionable
	sql=
		SELECT	$VERSION$.CATENTRY.$COLS:CATENTRY$, 
				$VERSION$.CATENTDESC.$COLS:CATENTDESC$
		FROM 	$VERSION$.CATENTRY 
					LEFT JOIN $VERSION$.CATENTDESC ON ($VERSION$.CATENTRY.CMVERSNINFO_ID = $VERSION$.CATENTDESC.CMVERSNINFO_ID AND $VERSION$.CATENTDESC.LANGUAGE_ID IN ($CONTROL:LANGUAGES$)) 
		WHERE 	$VERSION$.CATENTRY.CATENTRY_ID IN (?UniqueID?) AND $VERSION$.CATENTRY.CMVERSNINFO_ID = $VERSION_ID$
END_XPATH_TO_SQL_STATEMENT

SQL statement after substitution of version parameters:

SELECT	VCW_DEMO.CATENTRY.$COLS:CATENTRY$, 
		VCW_DEMO.CATENTDESC.$COLS:CATENTDESC$
FROM	 	VCW_DEMO.CATENTRY 
			LEFT JOIN VCW_DEMO.CATENTDESC ON (VCW_DEMO.CATENTRY.CMVERSNINFO_ID = VCW_DMEO.CATENTDESC.CMVERSNINFO_ID AND VCW_DMEO.CATENTDESC.LANGUAGE_ID IN ($CONTROL:LANGUAGES$)) 
WHERE 	VCW_DEMO.CATENTRY.CATENTRY_ID IN (?UniqueID?) AND 
		VCW_DEMO.CATENTRY.CMVERSNINFO_ID = 10501