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'jdbacl' stands for 'Java DataBase ACcess Layer' and provides utilities for accessing JDBC databases from Java programs, retrieving meta information in an object model and querying database data. 'rapiddweller jdbacl' is forked from Databene jdbacl by Volker Bergmann.
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/*
 * (c) Copyright 2010-2012 by Volker Bergmann. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, is permitted under the terms of the
 * GNU General Public License (GPL).
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * WITHOUT A WARRANTY OF ANY KIND. ALL EXPRESS OR IMPLIED CONDITIONS,
 * REPRESENTATIONS AND WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE
 * HEREBY EXCLUDED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

package com.rapiddweller.jdbacl.dialect;

import com.rapiddweller.common.ArrayBuilder;
import com.rapiddweller.jdbacl.DBUtil;
import com.rapiddweller.jdbacl.DatabaseDialect;
import com.rapiddweller.jdbacl.model.DBSequence;
import com.rapiddweller.jdbacl.sql.Query;

import java.math.BigInteger;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.regex.Pattern;

/**
 * {@link DatabaseDialect} implementation for the H2 database.
 * See H2 SQL grammar


 * Created: 28.03.2010 07:54:19
 *
 * @author Volker Bergmann
 * @since 0.6.0
 */
public class H2Dialect extends DatabaseDialect {

  private static final String DATE_PATTERN = "''yyyy-MM-dd''";
  private static final String TIME_PATTERN = "''HH:mm:ss''";
  private static final String DATETIME_PATTERN = "''yyyy-MM-dd HH:mm:ss''";

  /**
   * The Random pk name pattern.
   */
  final Pattern randomPKNamePattern = Pattern.compile("CONSTRAINT_\\w+");
  /**
   * The Random uk name pattern.
   */
  final Pattern randomUKNamePattern = Pattern.compile("CONSTRAINT_INDEX_\\w+");
  /**
   * The Random fk name pattern.
   */
  final Pattern randomFKNamePattern = Pattern.compile("CONSTRAINT_\\w+");
  /**
   * The Random index name pattern.
   */
  final Pattern randomIndexNamePattern = Pattern.compile("CONSTRAINT_INDEX_\\w+|PRIMARY_KEY_\\w+");

  /**
   * Instantiates a new H 2 dialect.
   */
  public H2Dialect() {
    super("h2", true, true, DATE_PATTERN, TIME_PATTERN, DATETIME_PATTERN);
  }

  @Override
  public boolean isDefaultCatalog(String catalog, String user) {
    return (catalog == null);
  }

  @Override
  public boolean isDefaultSchema(String schema, String user) {
    return "PUBLIC".equalsIgnoreCase(schema);
  }

  @Override
  public boolean isSequenceBoundarySupported() {
    return false;
  }

  @Override
  public DBSequence[] querySequences(Connection connection) throws SQLException {
    String query = "select SEQUENCE_CATALOG, SEQUENCE_SCHEMA, SEQUENCE_NAME, CURRENT_VALUE, INCREMENT, CACHE from information_schema.sequences";
    // TODO v0.8.2 restrict to catalog and schema, see http://www.h2database.com/html/grammar.html
    ArrayBuilder builder = new ArrayBuilder<>(DBSequence.class);
    ResultSet resultSet = DBUtil.executeQuery(query, connection);
    while (resultSet.next()) {
      String name = resultSet.getString("SEQUENCE_NAME");
      DBSequence sequence = new DBSequence(name, null);
      sequence.setStart(new BigInteger(resultSet.getString("CURRENT_VALUE")));
      sequence.setLastNumber(sequence.getStart());
      sequence.setIncrement(new BigInteger(resultSet.getString("INCREMENT")));
      sequence.setCache(resultSet.getLong("CACHE"));
      builder.add(sequence);
    }
    return builder.toArray();
  }

  @Override
  public String renderFetchSequenceValue(String sequenceName) {
    return "select next value for " + sequenceName;
  }

  @Override
  public void setNextSequenceValue(String sequenceName, long value, Connection connection) throws SQLException {
    DBUtil.executeUpdate(setSequenceValue(sequenceName, value), connection);
  }

  /**
   * Sets sequence value.
   *
   * @param sequenceName the sequence name
   * @param value        the value
   * @return the sequence value
   */
  public String setSequenceValue(String sequenceName, long value) {
    return "alter sequence " + sequenceName + " restart with " + value;
  }

  @Override
  public String renderDropSequence(String name) {
    return "drop sequence " + name;
  }

  @Override
  public boolean isDeterministicPKName(String pkName) {
    return !randomPKNamePattern.matcher(pkName).matches();
  }

  @Override
  public boolean isDeterministicUKName(String ukName) {
    return !randomUKNamePattern.matcher(ukName).matches();
  }

  @Override
  public boolean isDeterministicFKName(String fkName) {
    return !randomFKNamePattern.matcher(fkName).matches();
  }

  @Override
  public boolean isDeterministicIndexName(String indexName) {
    return !randomIndexNamePattern.matcher(indexName).matches();
  }

  @Override
  public boolean supportsRegex() {
    return true;
  }

  @Override
  public String regexQuery(String expression, boolean not, String regex) {
    return expression + (not ? " NOT" : "") + " REGEXP '" + regex + "'";
  }

  /**
   * restricts the query result set to a certain number of rows, optionally starting from an offset.
   *
   * @param rowOffset the number of rows to skip from the beginning of the result set;
   *                  use 0 for not skipping any.
   * @param rowCount  the number of rows to read;
   *                  use 0 for unlimited access
   */
  @Override
  public void restrictRownums(int rowOffset, int rowCount, Query query) {
    query.addOption("LIMIT " + rowCount); // note: LIMIT must not be left out
    if (rowOffset > 0) {
      query.addOption("OFFSET " + rowOffset); // note: The order LIMIT x OFFSET y is mandatory
    }
  }

}