org.jooq.Template Maven / Gradle / Ivy
/**
* Copyright (c) 2009-2015, Data Geekery GmbH (http://www.datageekery.com)
* All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Other licenses:
* -----------------------------------------------------------------------------
* Commercial licenses for this work are available. These replace the above
* ASL 2.0 and offer limited warranties, support, maintenance, and commercial
* database integrations.
*
* For more information, please visit: http://www.jooq.org/licenses
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*/
package org.jooq;
/**
* A functional interface to return custom {@link QueryPart} objects from input.
*
* This interface is used for templating in jOOQ. Any type of
* QueryPart can be created through templating mechanisms.
* Depending on the template, some input data is needed - for
* example an array or a collection of bind values.
*
* Simple examples of templates are plain SQL construction templates, which are
* used by jOOQ internally for all plain SQL factory methods. More sophisticated
* examples include XSL transformation templates, MyBatis templates, etc.
*
* An example using Apache Velocity is given here:
*
*
* class VelocityTemplate implements Template {
* private final String file;
*
* public VelocityTemplate(String file) {
* this.file = file;
* }
*
* public QueryPart transform(Object... input) {
* VelocityEngine ve = new VelocityEngine();
* ve.setProperty(RuntimeConstants.RESOURCE_LOADER, "file");
* ve.setProperty(RuntimeConstants.FILE_RESOURCE_LOADER_PATH, new File("authors-and-books.vm").getAbsolutePath());
* ve.setProperty(RuntimeConstants.FILE_RESOURCE_LOADER_CACHE, "true");
* ve.init();
*
* VelocityContext context = new VelocityContext();
* context.put("p", input);
*
* StringWriter writer = new StringWriter();
* ve.getTemplate(file, "UTF-8").merge(context, writer);
* return DSL.queryPart(writer.toString(), input);
* }
* }
*
* And then:
*
*
* DSL.using(configuration)
* .resultQuery(new VelocityTemplate("authors-and-books.vm"), 1, 2, 3)
* .fetch();
*
* With the contents of authors-and-books.vm being
*
*
* SELECT
* a.first_name,
* a.last_name,
* count(*)
* FROM
* t_author a
* LEFT OUTER JOIN
* t_book b ON a.id = b.author_id
* WHERE
* 1 = 0
* #foreach ($param in $p)
* OR a.id = ?
* #end
* GROUP BY
* a.first_name,
* a.last_name
* ORDER BY
* a.id ASC
*
*
* @deprecated - This type is still very experimental and not yet released to a
* broad public. Do not use this type yet.
* @author Lukas Eder
*/
@Deprecated
public interface Template {
/**
* Transform some input data into a {@link QueryPart}.
*/
QueryPart transform(Object... input);
}