jdbcdatabasemetadata.java

hsqldb是100％java实现的数据库,是一个开放源代码的JAVA数据库 l 具有标准的SQL语法和JAVA接口 l HSQLDB可以自由使用和分发 l 非常简洁和快速的

     * Retrieves whether this database uses a file for each table. <p>
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * Up to and including 1.7.2, HSQLDB does not use a file for each table.
     * This method always returns <code>false</code>.
     * </div>
     * <!-- end release-specific documentation -->
     * @return <code>true</code> if this database uses a local file for each table;
     *      <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    public boolean usesLocalFilePerTable() throws SQLException {
        return false;
    }

    /**
     * Retrieves whether this database treats mixed case unquoted SQL identifiers as
     * case sensitive and as a result stores them in mixed case. <p>
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * HSQLDB treats unquoted identifiers as case insensitive and stores
     * them in upper case. It treats quoted identifiers as case sensitive and
     * stores them verbatim; this method always returns <code>false</code>.
     * </div>
     * <!-- end release-specific documentation -->
     *
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    public boolean supportsMixedCaseIdentifiers() throws SQLException {
        return false;
    }

    /**
     * Retrieves whether this database treats mixed case unquoted SQL identifiers as
     * case insensitive and stores them in upper case. <p>
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * HSQLDB treats unquoted identifiers as case insensitive and stores
     * them in upper case. It treats quoted identifiers as case sensitive and
     * stores them verbatim; this method always returns <code>true</code>.
     * </div>
     * <!-- end release-specific documentation -->
     *
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    public boolean storesUpperCaseIdentifiers() throws SQLException {
        return true;
    }

    /**
     * Retrieves whether this database treats mixed case unquoted SQL identifiers as
     * case insensitive and stores them in lower case. <p>
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * HSQLDB treats unquoted identifiers as case insensitive and stores
     * them in upper case. It treats quoted identifiers as case sensitive and
     * stores them verbatim; this method always returns <code>false</code>.
     * </div>
     * <!-- end release-specific documentation -->
     *
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    public boolean storesLowerCaseIdentifiers() throws SQLException {
        return false;
    }

    /**
     * Retrieves whether this database treats mixed case unquoted SQL identifiers as
     * case insensitive and stores them in mixed case. <p>
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * HSQLDB treats unquoted identifiers as case insensitive and stores
     * them in upper case. It treats quoted identifiers as case sensitive and
     * stores them verbatim; this method always returns <code>false</code>.
     * </div>
     * <!-- end release-specific documentation -->
     *
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    public boolean storesMixedCaseIdentifiers() throws SQLException {
        return false;
    }

    /**
     * Retrieves whether this database treats mixed case quoted SQL identifiers as
     * case sensitive and as a result stores them in mixed case. <p>
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * HSQLDB treats unquoted identifiers as case insensitive and stores
     * them in upper case. It treats quoted identifiers as case sensitive and
     * stores them verbatim; this method always returns <code>true</code>.
     * </div>
     * <!-- end release-specific documentation -->
     *
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    public boolean supportsMixedCaseQuotedIdentifiers() throws SQLException {
        return true;
    }

    /**
     * Retrieves whether this database treats mixed case quoted SQL identifiers as
     * case insensitive and stores them in upper case. <p>
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * HSQLDB treats unquoted identifiers as case insensitive and stores
     * them in upper case. It treats quoted identifiers as case sensitive and
     * stores them verbatim; this method always returns <code>false</code>.
     * </div>
     * <!-- end release-specific documentation -->
     *
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    public boolean storesUpperCaseQuotedIdentifiers() throws SQLException {
        return false;
    }

    /**
     * Retrieves whether this database treats mixed case quoted SQL identifiers as
     * case insensitive and stores them in lower case. <p>
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * HSQLDB treats unquoted identifiers as case insensitive and stores
     * them in upper case. It treats quoted identifiers as case sensitive and
     * stores them verbatim; this method always returns <code>false</code>.
     * </div>
     * <!-- end release-specific documentation -->
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    public boolean storesLowerCaseQuotedIdentifiers() throws SQLException {
        return false;
    }

    /**
     * Retrieves whether this database treats mixed case quoted SQL identifiers as
     * case insensitive and stores them in mixed case. <p>
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * HSQLDB treats unquoted identifiers as case insensitive and stores
     * them in upper case. It treats quoted identifiers as case sensitive and
     * stores them verbatim; this method always returns <code>false</code>.
     * </div>
     * <!-- end release-specific documentation -->
     *
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    public boolean storesMixedCaseQuotedIdentifiers() throws SQLException {
        return false;
    }

    /**
     * Retrieves the string used to quote SQL identifiers.
     * This method returns a space " " if identifier quoting is not supported. <p>
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * HSQLDB uses the standard SQL identifier quote character
     * (the double quote character); this method always returns <b>"</b>.
     * </div>
     * <!-- end release-specific documentation -->
     * @return the quoting string or a space if quoting is not supported
     * @exception SQLException if a database access error occurs
     */
    public String getIdentifierQuoteString() throws SQLException {
        return "\"";
    }

//fredt@users 20020429 - JavaDoc comment - in 1.7.1 there are keywords such
// as TEMP, TEXT, CACHED that are not SQL 92 keywords

    /**
     * Retrieves a comma-separated list of all of this database's SQL keywords
     * that are NOT also SQL92 keywords. <p>
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * The list returned contains HSQLDB keywords that are not in the list
     * of reserved words. Some of these are in the list reserved
     * words for SQL 2003 but are not SQL92 keywords.
     * </div>
     * <!-- end release-specific documentation -->
     *
     *
     * @return the list of this database's keywords that are not also
     *       SQL92 keywords
     * @exception SQLException if a database access error occurs
     */
    public String getSQLKeywords() throws SQLException {

        return "BEFORE,BIGINT,BINARY,CACHED,DATETIME,"
               + "LIMIT,LONGVARBINARY,LONGVARCHAR,OBJECT,OTHER,SAVEPOINT,"
               + "TEMP,TEXT,TOP,TRIGGER,TINYINT,VARBINARY,VARCHAR_IGNORECASE";
    }

    /**
     * Retrieves a comma-separated list of math functions available with
     * this database.  These are the Open Group CLI math function names used in
     * the JDBC function escape clause.
     * @return the list of math functions supported by this database
     * @exception SQLException if a database access error occurs
     */
    public String getNumericFunctions() throws SQLException {
        return StringUtil.getList(Library.sNumeric, ",", "");
    }

    /**
     * Retrieves a comma-separated list of string functions available with
     * this database.  These are the  Open Group CLI string function names used
     * in the JDBC function escape clause.
     * @return the list of string functions supported by this database
     * @exception SQLException if a database access error occurs
     */
    public String getStringFunctions() throws SQLException {
        return StringUtil.getList(Library.sString, ",", "");
    }

    /**
     * Retrieves a comma-separated list of system functions available with
     * this database.  These are the  Open Group CLI system function names used
     * in the JDBC function escape clause.
     * @return a list of system functions supported by this database
     * @exception SQLException if a database access error occurs
     */
    public String getSystemFunctions() throws SQLException {
        return StringUtil.getList(Library.sSystem, ",", "");
    }

    /**
     * Retrieves a comma-separated list of the time and date functions available
     * with this database.
     * @return the list of time and date functions supported by this database
     * @exception SQLException if a database access error occurs
     */
    public String getTimeDateFunctions() throws SQLException {
        return StringUtil.getList(Library.sTimeDate, ",", "");
    }

    /**
     * Retrieves the string that can be used to escape wildcard characters.
     * This is the string that can be used to escape '_' or '%' in
     * the catalog search parameters that are a pattern (and therefore use one
     * of the wildcard characters).
     *
     * <P>The '_' character represents any single character;
     * the '%' character represents any sequence of zero or
     * more characters. <p>
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * HSQLDB uses the "\" character to escape wildcard characters.
     * </div>
     * <!-- end release-specific documentation -->
     *
     *
     * @return the string used to escape wildcard characters
     * @exception SQLException if a database access error occurs
     */
    public String getSearchStringEscape() throws SQLException {
        return "\\";
    }

    /**
     * Retrieves all the "extra" characters that can be used in unquoted
     * identifier names (those beyond a-z, A-Z, 0-9 and _). <p>
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * HSQLDB does not support using any "extra" characters in unquoted
     * identifier names; this method always returns the empty String.
     * </div>
     * <!-- end release-specific documentation -->
     *
     *
     * @return the string containing the extra characters
     * @exception SQLException if a database access error occurs
     */
    public String getExtraNameCharacters() throws SQLException {
        return "";
    }

    //--------------------------------------------------------------------
    // Functions describing which features are supported.

    /**
     * Retrieves whether this database supports <code>ALTER TABLE</code>