tinysqldatabasemetadata.java

TinySQL是一个轻量级的纯java数据库引擎

/*
 * tinySQLDatabaseMetaData.java
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 * $Author: davis $
 * $Date: 2004/12/18 21:32:33 $
 * $Revision: 1.1 $
 */

/**
dBase read/write access <br> 
@author Brian Jepson <[e-mail]>
@author Marcel Ruff <[e-mail]> Added write access to dBase and JDK 2 support
*/
package com.sqlmagic.tinysql;

/**
 * Comprehensive information about the database as a whole.
 *
 * Many of the methods here return lists of information in 
 * the form of ResultSet objects.
 * You can use the normal ResultSet methods such as getString and getInt 
 * to retrieve the data from these ResultSets.  If a given form of
 * metadata is not available, these methods should throw an SQLException.
 *
 * Some of these methods take arguments that are String patterns.  These
 * arguments all have names such as fooPattern.  Within a pattern String, "%"
 * means match any substring of 0 or more characters, and "_" means match
 * any one character. Only metadata entries matching the search pattern 
 * are returned. If a search pattern argument is set to a null ref, 
 * that argument's criteria will be dropped from the search.
 * 
 * An SQLException will be thrown if a driver does not support a meta
 * data method.  In the case of methods that return a ResultSet,
 * either a ResultSet (which may be empty) is returned or a
 * SQLException is thrown.
 */
import java.sql.SQLException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Types;

public class tinySQLDatabaseMetaData implements java.sql.DatabaseMetaData {

  /**
   *
   * The result set.
   *
   */
  private Connection connection = null;

  public tinySQLDatabaseMetaData(Connection connection) {
    this.connection = connection;
  }

    //----------------------------------------------------------------------
        // First, a variety of minor information about the target database.

    /**
     * Can all the procedures returned by getProcedures be called by the
     * current user?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
     public boolean allProceduresAreCallable() {
          return false;
        }

    /**
     * Can all the tables returned by getTable be SELECTed by the
     * current user?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
     public   boolean allTablesAreSelectable() {
          return true;
        }

    /**
     * What's the url for this database?
     *
     * @return the url or null if it cannot be generated
     * @exception SQLException if a database access error occurs
     */
     public   String getURL() {
          return ""; // !!!
        }

    /**
     * What's our user name as known to the database?
     *
     * @return our database user name
     * @exception SQLException if a database access error occurs
     */
     public   String getUserName() {
          return "";
        }

    /**
     * Is the database in read-only mode?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
     public   boolean isReadOnly() {
          return false;
        }

    /**
     * Are NULL values sorted high?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
     public   boolean nullsAreSortedHigh() {
          return false;
        }

    /**
     * Are NULL values sorted low?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
     public   boolean nullsAreSortedLow() {
          return !nullsAreSortedHigh();
        }

    /**
     * Are NULL values sorted at the start regardless of sort order?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
     public   boolean nullsAreSortedAtStart() {
          return false;
        }

    /**
     * Are NULL values sorted at the end regardless of sort order?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
     public   boolean nullsAreSortedAtEnd() {
          return !nullsAreSortedAtStart();
        }

    /**
     * What's the name of this database product?
     *
     * @return database product name
     * @exception SQLException if a database access error occurs
     */
     public   String getDatabaseProductName() {
          return "tinySQL";
        }

    /**
     * What's the version of this database product?
     *
     * @return database version
     * @exception SQLException if a database access error occurs
     */
     public   String getDatabaseProductVersion() {
          return "dBase III";
        }

    /**
     * What's the name of this JDBC driver?
     *
     * @return JDBC driver name
     * @exception SQLException if a database access error occurs
     */
     public   String getDriverName() {
          return "com.sqlmagic.tinysql.dbfFileDriver";
        }

    /**
     * What's the version of this JDBC driver?
     *
     * @return JDBC driver version
     * @exception SQLException if a database access error occurs
     */
     public   String getDriverVersion() {
          return tinySQLGlobals.VERSION;
        }

    /**
     * What's this JDBC driver's major version number?
     *
     * @return JDBC driver major version
     */
    public    int getDriverMajorVersion() {
          return 2;
        }

    /**
     * What's this JDBC driver's minor version number?
     *
     * @return JDBC driver minor version number
     */
    public    int getDriverMinorVersion() {
          return 1;
        }

    /**
     * Does the database store tables in a local file?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
     public   boolean usesLocalFiles() {
          return true;
        }

    /**
     * Does the database use a file for each table?
     *
     * @return true if the database uses a local file for each table
     * @exception SQLException if a database access error occurs
     */
        public boolean usesLocalFilePerTable() {
          return true;
        }

    /**
     * Does the database treat mixed case unquoted SQL identifiers as
     * case sensitive and as a result store them in mixed case?
     *
     * A JDBC Compliant<sup><font size=-2>TM</font></sup> driver will always return false.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
        public boolean supportsMixedCaseIdentifiers() {
          return false;
        }

    /**
     * Does the database treat mixed case unquoted SQL identifiers as
     * case insensitive and store them in upper case?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
        public boolean storesUpperCaseIdentifiers() {
          return true;
        }

    /**
     * Does the database treat mixed case unquoted SQL identifiers as
     * case insensitive and store them in lower case?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
        public boolean storesLowerCaseIdentifiers() {
          return !storesUpperCaseIdentifiers();
        }

    /**
     * Does the database treat mixed case unquoted SQL identifiers as
     * case insensitive and store them in mixed case?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
        public boolean storesMixedCaseIdentifiers() {
          return supportsMixedCaseIdentifiers();
        }

    /**
     * Does the database treat mixed case quoted SQL identifiers as
     * case sensitive and as a result store them in mixed case?
     *
     * A JDBC Compliant<sup><font size=-2>TM</font></sup> driver will always return true.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
        public boolean supportsMixedCaseQuotedIdentifiers() {
          return supportsMixedCaseIdentifiers();
        }

    /**
     * Does the database treat mixed case quoted SQL identifiers as
     * case insensitive and store them in upper case?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
        public boolean storesUpperCaseQuotedIdentifiers() {
          return true;
        }

    /**
     * Does the database treat mixed case quoted SQL identifiers as
     * case insensitive and store them in lower case?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
        public boolean storesLowerCaseQuotedIdentifiers() {
          return !storesUpperCaseQuotedIdentifiers();
        }

    /**
     * Does the database treat mixed case quoted SQL identifiers as
     * case insensitive and store them in mixed case?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
        public boolean storesMixedCaseQuotedIdentifiers() {
          return supportsMixedCaseIdentifiers();
        }

    /**
     * What's the string used to quote SQL identifiers?
     * This returns a space " " if identifier quoting isn't supported.
     *
     * A JDBC Compliant<sup><font size=-2>TM</font></sup> 
         * driver always uses a double quote character.
     *
     * @return the quoting string
     * @exception SQLException if a database access error occurs
     */
        public String getIdentifierQuoteString() {
          return "\""; // "'";
        }

    /**
     * Gets a comma-separated list of all a database's SQL keywords
     * that are NOT also SQL92 keywords.
     *
     * @return the list 
     * @exception SQLException if a database access error occurs
     */
        public String getSQLKeywords() {
          return "";
        }

    /**
     * Gets a comma-separated list of math functions.  These are the 
     * X/Open CLI math function names used in the JDBC function escape 
     * clause.
     *
     * @return the list
     * @exception SQLException if a database access error occurs
     */
        public String getNumericFunctions() {
          return "";
        }