net.java.ao.schema.AutoIncrement Maven / Gradle / Ivy
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/*
* Copyright 2007 Daniel Spiewak
*
* 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.
*/
package net.java.ao.schema;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Tags a specific method as representing a field who's value should be
* auto-generated by the database in some sort of numeric sequence
* (usually ascending order). Not all databases support this function
* as a field modifier. For example, PostgreSQL requires the use of the
* SERIAL type. Thus, this annotation imposes priority
* over the defined type and should only be used on int
* or long fields (short is also acceptable if
* great care is taken).
*
* For databases which really have no way of supporting this exact
* functionality (like Oracle), implementation may be omitted as long as
* the 90% case is still covered. For example, the Oracle implementation
* of this property relies on the fact that PRIMARY KEY fields are already
* auto-generated if no value is specified.
*
* This annotation is only relevant to migrations. It has no effect upon
* "runtime" entity usage.
*
* @author Daniel Spiewak
*/
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface AutoIncrement {
}