jdbcdatabasemetadata.java

Java写的含有一个jdbc驱动的小型数据库数据库引擎

	if (Trace.TRACE) {
	    Trace.trace();
	}

	return getList(Library.sNumeric);
    }

    /**
     * Gets a comma-separated list of string functions.  These are the
     * X/Open CLI string function names used in the JDBC function escape
     * clause.
     *
     * @return the list
     */
    public String getStringFunctions() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return getList(Library.sString);
    }

    /**
     * Gets a comma-separated list of system functions.  These are the
     * X/Open CLI system function names used in the JDBC function escape
     * clause.
     *
     * @return the list
     */
    public String getSystemFunctions() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return getList(Library.sSystem);
    }

    /**
     * Gets a comma-separated list of time and date functions.
     *
     * @return the list
     */
    public String getTimeDateFunctions() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return getList(Library.sTimeDate);
    }

    /**
     * Gets the string that can be used to escape wildcard characters.
     * This is the string that can be used to escape '_' or '%' in
     * the string pattern style catalog search parameters.
     *
     * <P>The '_' character represents any single character.
     * <P>The '%' character represents any sequence of zero or
     * more characters.
     *
     * @return the string used to escape wildcard characters
     */
    public String getSearchStringEscape() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return "\\";
    }

    /**
     * Gets all the "extra" characters that can be used in unquoted
     * identifier names (those beyond a-z, A-Z, 0-9 and _).
     *
     * @return the string containing the extra characters
     */
    public String getExtraNameCharacters() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return "";
    }

    /**
     * Is "ALTER TABLE" with add column supported?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsAlterTableWithAddColumn() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;
    }

    /**
     * Is "ALTER TABLE" with drop column supported?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsAlterTableWithDropColumn() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;
    }

    /**
     * Is column aliasing supported?
     *
     * <P>If so, the SQL AS clause can be used to provide names for
     * computed columns or to provide alias names for columns as
     * required.
     *
     * A JDBC Compliant<sup><font size=-2>TM</font></sup> driver
     * always returns true.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsColumnAliasing() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;

	// InterBase (iscdrv32.dll) returns false
    }

    /**
     * Are concatenations between NULL and non-NULL values NULL?
     *
     * A JDBC Compliant<sup><font size=-2>TM</font></sup> driver always
     * returns true.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean nullPlusNonNullIsNull() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;

	// Access (odbcjt32.dll) returns false
    }

    /**
     * Is the CONVERT function between SQL types supported?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsConvert() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;
    }

    /**
     * Is CONVERT between the given SQL types supported?
     * <P><font color="#009900">
     * In HSQL Database Engine, conversions are made over Strings, so
     * everything theoretically is possible.
     * </font><P>
     * @param fromType the type to convert from
     * @param toType the type to convert to
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsConvert(int fromType, int toType) {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;
    }

    /**
     * Are table correlation names supported?
     *
     * A JDBC Compliant<sup><font size=-2>TM</font></sup> driver
     * always returns true.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsTableCorrelationNames() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;
    }

    /**
     * If table correlation names are supported, are they restricted
     * to be different from the names of the tables?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsDifferentTableCorrelationNames() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;
    }

    /**
     * Are expressions in "ORDER BY" lists supported?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsExpressionsInOrderBy() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;
    }

    /**
     * Can an "ORDER BY" clause use columns not in the SELECT statement?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsOrderByUnrelated() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;
    }

    /**
     * Is some form of "GROUP BY" clause supported?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsGroupBy() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;
    }

    /**
     * Can a "GROUP BY" clause use columns not in the SELECT?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsGroupByUnrelated() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;
    }

    /**
     * Can a "GROUP BY" clause add columns not in the SELECT
     * provided it specifies all the columns in the SELECT?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsGroupByBeyondSelect() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;
    }

    /**
     * Is the escape character in "LIKE" clauses supported?
     *
     * A JDBC Compliant<sup><font size=-2>TM</font></sup> driver
     * always returns true.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsLikeEscapeClause() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;
    }

    /**
     * Are multiple ResultSets from a single execute supported?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsMultipleResultSets() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;
    }

    /**
     * Can we have multiple transactions open at once (on different
     * connections)?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsMultipleTransactions() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;
    }

    /**
     * Can columns be defined as non-nullable?
     *
     * A JDBC Compliant<sup><font size=-2>TM</font></sup> driver
     * always returns true.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsNonNullableColumns() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;
    }

    /**
     * Is the ODBC Minimum SQL grammar supported?
     *
     * All JDBC Compliant<sup><font size=-2>TM</font></sup> drivers
     * must return true.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsMinimumSQLGrammar() {
	if (Trace.TRACE) {
	    Trace.trace();

	    // todo
	}

	return false;
    }

    /**
     * Is the ODBC Core SQL grammar supported?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsCoreSQLGrammar() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;
    }

    /**
     * Is the ODBC Extended SQL grammar supported?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsExtendedSQLGrammar() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;
    }

    /**
     * Is the ANSI92 entry level SQL grammar supported?
     *
     * All JDBC Compliant<sup><font size=-2>TM</font></sup> drivers must
     * return true.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsANSI92EntryLevelSQL() {
	if (Trace.TRACE) {
	    Trace.trace();

	    // todo
	}

	return false;
    }

    /**
     * Is the ANSI92 intermediate SQL grammar supported?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsANSI92IntermediateSQL() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;
    }

    /**
     * Is the ANSI92 full SQL grammar supported?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsANSI92FullSQL() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;
    }

    /**
     * Is the SQL Integrity Enhancement Facility supported?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsIntegrityEnhancementFacility() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return false;
    }

    /**
     * Is some form of outer join supported?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsOuterJoins() {
	if (Trace.TRACE) {
	    Trace.trace();
	}

	return true;
    }

    /**
     * Are full nested outer joins supported?
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     */
    public boolean supportsFullOuterJoins() {
	if (Trace.TRACE) {
	    Trace.trace();

	    // todo
	}

	return false;
    }

    /**