org.jooq.Generator Maven / Gradle / Ivy
/*
* 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
* Apache-2.0 license and offer limited warranties, support, maintenance, and
* commercial database integrations.
*
* For more information, please visit: http://www.jooq.org/licenses
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*/
package org.jooq;
import java.io.Serializable;
import java.util.function.Function;
import org.jooq.impl.QOM.GenerationLocation;
import org.jooq.impl.QOM.GenerationOption;
/**
* A generator can be used with {@link DataType#generatedAlwaysAs(Generator)} to
* implement dynamic, client side computed columns, i.e. computed columns with
* {@link GenerationLocation#CLIENT}.
*
* There are two types of client side computed columns:
*
* - {@link GenerationOption#STORED}: The computation is performed when
* writing to a record via {@link Insert}, {@link Update}, or {@link Merge}
* - {@link GenerationOption#VIRTUAL}: The computation is performed when
* reading a record via {@link Select}, or the
RETURNING clause of
* {@link Insert}, {@link Update}, {@link Delete}.
*
*
* Depending on the type of client side computed column, the exact time when the
* computation is performed may differ, practically. It is not specified, when
* it happens, but users may assume that it happens only once per query
* rendering and {@link Field} expression which references a {@link Generator},
* independently of how many times the resulting expression is repeated in the
* resulting SQL query.
*
* This API is part of a commercial only feature. To use this feature, please
* use the jOOQ Professional Edition or the jOOQ Enterprise Edition.
*
* @author Lukas Eder
*/
@FunctionalInterface
public interface Generator, T> extends Function, Field>, Serializable {
/**
* Whether this generator supports a given statement type.
*
* Implementations may choose to deactivate themselves for some statement
* types, e.g. if they want to be invoked only for
* {@link GeneratorStatementType#INSERT}.
*
* @param statementType The statement type.
*/
default boolean supports(GeneratorStatementType statementType) {
return true;
}
}