com.github.drinkjava2.jdialects.id.IdentityIdGenerator Maven / Gradle / Ivy

Go to download
/*
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later. See
 * the lgpl.txt file in the root directory or
 * .
 */
package com.github.drinkjava2.jdialects.id;

import com.github.drinkjava2.jdbpro.NormalJdbcTool;
import com.github.drinkjava2.jdialects.DDLFeatures;
import com.github.drinkjava2.jdialects.Dialect;
import com.github.drinkjava2.jdialects.DialectException;
import com.github.drinkjava2.jdialects.StrUtils;
import com.github.drinkjava2.jdialects.Type;
import com.github.drinkjava2.jdialects.annotation.jpa.GenerationType;

/**
 * Define an Identity type generator, supported by MySQL, SQL Server, DB2,
 * Derby, Sybase, PostgreSQL
 * 
 * 
 * @author Yong Zhu
 * @version 1.0.0
 * @since 1.0.0
 */
public class IdentityIdGenerator implements IdGenerator {
	public static final IdentityIdGenerator INSTANCE = new IdentityIdGenerator();

	@Override
	public GenerationType getGenerationType() {
		return GenerationType.IDENTITY;
	}

	@Override
	public String getIdGenName() {
		return "IDENTITY";
	}
	
	@Override
	public Boolean dependOnAutoIdGenerator() {
		return false;
	}

	@Override
	public Object getNextID(NormalJdbcTool jdbc, Dialect dialect, Type dataType) {
		if (!dialect.getDdlFeatures().getSupportsIdentityColumns())
			throw new DialectException("Dialect '" + dialect + "' does not support identity type");
		String sql = null;
		if (Type.BIGINT.equals(dataType))
			sql = dialect.getDdlFeatures().getIdentitySelectStringBigINT();
		else
			sql = dialect.getDdlFeatures().getIdentitySelectString();
		if (StrUtils.isEmpty(sql) || DDLFeatures.NOT_SUPPORT.equals(sql))
			throw new DialectException("Dialect '" + dialect + "' does not support identity type");
		return jdbc.nQueryForObject(sql);
	}

	@Override
	public IdGenerator newCopy() {
		return INSTANCE;
	}
}