code: package it.unibz.inf.ontop.dbschema.impl;
  
  
  /*
   * #%L
   * ontop-obdalib-core
   * %%
   * Copyright (C) 2009 - 2014 Free University of Bozen-Bolzano
   * %%
   * 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.
   * #L%
   */
  
  
  import it.unibz.inf.ontop.dbschema.QuotedID;
  
  import javax.annotation.Nonnull;
  import java.util.Objects;
  
  /**
   * Creates QuotedIdentifiers following the rules of MySQL:<br>
   *    - unquoted table identifiers are preserved<br>
   *    - unquoted column identifiers are not case-sensitive<br>
   *    - quoted identifiers are preserved
   *
   *
   * https://dev.mysql.com/doc/refman/8.0/en/identifier-case-sensitivity.html
   *
   * How table and database names are stored on disk and used in MySQL is affected
   * by the lower_case_table_names system variable, which you can set when starting mysqld.
   *
   * Column, index, and stored routine names are not case sensitive on any platform, nor are column aliases.
   *
   * https://dev.mysql.com/doc/refman/8.0/en/identifiers.html
   *
   * The identifier quote character is the backtick (`):
   * If the ANSI_QUOTES SQL mode is enabled, it is also permissible to quote identifiers
   * within double quotation marks. The ANSI_QUOTES mode causes the server to interpret
   * double-quoted strings as identifiers. Consequently, when this mode is enabled,
   * string literals must be enclosed within single quotation marks.
   *
   * @author Roman Kontchakov
   *
   */
  
  public abstract class MySQLAbstractQuotedIDFactory extends SQLStandardQuotedIDFactory {
  
  	private static final String MY_SQL_QUOTATION_STRING = "`";
  
  	protected QuotedID createFromString(@Nonnull String s, boolean caseSensitive) {
  		Objects.requireNonNull(s);
  
  		if (s.startsWith(MY_SQL_QUOTATION_STRING) && s.endsWith(MY_SQL_QUOTATION_STRING))
  			return new QuotedIDImpl(s.substring(1, s.length() - 1), MY_SQL_QUOTATION_STRING, caseSensitive);
  
  		if (s.startsWith(QUOTATION_STRING) && s.endsWith(QUOTATION_STRING))
  			return new QuotedIDImpl(s.substring(1, s.length() - 1), MY_SQL_QUOTATION_STRING, caseSensitive);
  
  		return new QuotedIDImpl(s, NO_QUOTATION, caseSensitive);
  	}
  
  
  	@Override
  	public String getIDQuotationString() {
  		return MY_SQL_QUOTATION_STRING;
  	}	
  }
  