jdbcdatabasemetadata.java

Java写的含有一个jdbc驱动的小型数据库数据库引擎

/*
 * jdbcDatabaseMetaData.java
 *
 * Copyright (c) 2001, The HSQL Development Group
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 *
 * Neither the name of the HSQL Development Group nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS 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.
 *
 * This package is based on HypersonicSQL, originally developed by Thomas Mueller.
 *
 */
package org.hsqldb;

import java.sql.*;

/**
 * Comprehensive information about the database as a whole.
 *
 * <P>Many of the methods here return lists of information in
 * the form of <code>ResultSet</code> 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.
 *
 * <P>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.
 *
 * <P>An <code>SQLException</code> 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.
 */
public class jdbcDatabaseMetaData implements DatabaseMetaData {
    private jdbcConnection cConnection;

    /**
     * Constructor declaration
     *
     *
     * @param c
     */
    jdbcDatabaseMetaData(jdbcConnection c) {
	cConnection = c;
    }

    /**
     * Can all the procedures returned by getProcedures be called by the
     * current user?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean allProceduresAreCallable() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;
    }

    /**
     * Can all the tables returned by getTable be SELECTed by the
     * current user?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean allTablesAreSelectable() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;
    }

    /**
     * What's the url for this database?
     *
     * @return the url
     */
    public String getURL() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return "jdbc:hsqldb:" + cConnection.getName();
    }

    /**
     * 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() throws SQLException {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	ResultSet r = executeSelect("SYSTEM_CONNECTIONINFO", "KEY='USER'");

	r.next();

	return r.getString(2);
    }

    /**
     * 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() throws SQLException {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return cConnection.isReadOnly();
    }

    /**
     * Are NULL values sorted high?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean nullsAreSortedHigh() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;
    }

    /**
     * Are NULL values sorted low?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean nullsAreSortedLow() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;
    }

    /**
     * Are NULL values sorted at the start regardless of sort order?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean nullsAreSortedAtStart() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;
    }

    /**
     * Are NULL values sorted at the end regardless of sort order?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean nullsAreSortedAtEnd() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;
    }

    /**
     * What's the name of this database product?
     *
     * @return database product name
     */
    public String getDatabaseProductName() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return jdbcDriver.PRODUCT;
    }

    /**
     * What's the version of this database product?
     *
     * @return database version
     */
    public String getDatabaseProductVersion() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return jdbcDriver.VERSION;
    }

    /**
     * What's the name of this JDBC driver?
     *
     * @return JDBC driver name
     */
    public String getDriverName() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return jdbcDriver.PRODUCT + " Driver";
    }

    /**
     * What's the version of this JDBC driver?
     *
     * @return JDBC driver version
     */
    public String getDriverVersion() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return jdbcDriver.VERSION;
    }

    /**
     * What's this JDBC driver's major version number?
     *
     * @return JDBC driver major version
     */
    public int getDriverMajorVersion() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return jdbcDriver.MAJOR;
    }

    /**
     * What's this JDBC driver's minor version number?
     *
     * @return JDBC driver minor version number
     */
    public int getDriverMinorVersion() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return jdbcDriver.MINOR;
    }

    /**
     * Does the database store tables in a local file?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean usesLocalFiles() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return cConnection.usesLocalFiles();
    }

    /**
     * Does the database use a file for each table?
     *
     * @return true if the database uses a local file for each table
     */
    public boolean usesLocalFilePerTable() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;
    }

    /**
     * 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
     */
    public boolean supportsMixedCaseIdentifiers() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	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
     */
    public boolean storesUpperCaseIdentifiers() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	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
     */
    public boolean storesLowerCaseIdentifiers() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;
    }

    /**
     * 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
     */
    public boolean storesMixedCaseIdentifiers() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;
    }

    /**
     * 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
     */
    public boolean supportsMixedCaseQuotedIdentifiers() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;

	// InterBase (iscdrv32.dll) returns false
    }

    /**
     * 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
     */
    public boolean storesUpperCaseQuotedIdentifiers() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;
    }

    /**
     * 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
     */
    public boolean storesLowerCaseQuotedIdentifiers() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;
    }

    /**
     * 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
     */
    public boolean storesMixedCaseQuotedIdentifiers() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;

	// No: as case sensitive.
    }

    /**
     * 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
     */
    public String getIdentifierQuoteString() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return "\"";

	// InterBase (iscdrv32.dll) returns ""
    }

    /**
     * Gets a comma-separated list of all a database's SQL keywords
     * that are NOT also SQL92 keywords.
     *
     * @return the list
     */
    public String getSQLKeywords() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	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
     */
    public String getNumericFunctions() {