JPA Translator - Teiid 8.3

Think this one as a reverse to what Hibernate provides. If you have JPA based store and have a supporting object model, this translator can will reverse your object model into relational model, where you can integrate with other relational or non-relational sources.

Native Queries

JPA source procedures may be created using the teiid_rel:native-query extension - see Parameterizable Native Queries. The procedure will invoke the native-query similar to an native procedure call with the benefits that the query is predetermined and that result column types are known, rather than requiring the use of ARRAYTABLE or similar functionality.

Native Procedure

This feature is turned off by default because of the security risk this exposes to execute any command against the source. To enable this feature, override the translator property called "SupportsNativeQueries" to true. Look for Override Execution Properties above.

JPA translator provides a procedure with name native that gives ability to execute any ad-hoc native JPA-QL queries directly against the source without any Teiid parsing or resolving. Since the metadata of this procedure's execution results are not known to the Teiid and they are returned as object array. User can use ARRAYTABLE to construct a build a tabular output for consumption by client applications. Teiid exposes this procedure with a simple query structure as below

Select

Select Example

SELECT x.* FROM (call pm1.native('search;FROM Account')) w,
 ARRAYTABLE(w.tuple COLUMNS "id" string , "type" string, "name" String) AS x

from the above code, the "search" keyword followed by a query statement - see Parameterizable Native Queries to substitute parameter values.

Delete

Delete Example

SELECT x.* FROM (call pm1.native('delete;<jpa-ql>')) w,
 ARRAYTABLE(w.tuple COLUMNS "updatecount" integer) AS x

form the above code, the "delete" keyword followed by JPA-QL for delete operation.

Update

Create Example

SELECT x.* FROM
 (call pm1.native('update;<jpa-ql>')) w,
 ARRAYTABLE(w.tuple COLUMNS "update_count" integer) AS x

form the above code, the "update" keyword must be followed by JPA-QL for the update statement.

Create

Update Example

SELECT x.* FROM
 (call pm1.native('create;', <entity>)) w,
 ARRAYTABLE(w.tuple COLUMNS "update_count" integer) AS x

Create operation needs to send "create" word as marker and send the entity as a the first parameter.

By default the name of the procedure that executes the queries directly is called native, however user can set Override Execution Properties property on NativeQueryProcedureName in vdb.xml file to change it to any other procedure name.