ssresultset.java

這是一個油Java實作的資料庫系統 是個入門的好材料

    
    
    /**
     * Test if it on the insert row.
     * @throws SQLException if on the insert row
     */
    private void testNotInsertRow() throws SQLException{
        if(isInsertRow){
            throw SmallSQLException.create(Language.RSET_ON_INSERT_ROW);
        }
    }
    
    public void updateRow() throws SQLException {
        try {
        	if(values == null){
                // no changes then also no update needed
                return;
            }
       		st.con.log.println("updateRow()");
            testNotInsertRow();
            final CommandSelect command = getCmd();
            command.updateRow( st.con, values);
            command.relative(0);  //refresh the row
            clearRowBuffer();
        } catch (Exception e) {
            throw SmallSQLException.createFromException(e);
        }
    }
    
    
    public void deleteRow() throws SQLException {
		st.con.log.println("deleteRow()");
        testNotInsertRow();
    	getCmd().deleteRow(st.con);
        clearRowBuffer();
    }
    public void refreshRow() throws SQLException {
        testNotInsertRow();
        relative(0);
    }
    

    public void cancelRowUpdates() throws SQLException{
        testNotInsertRow();
        clearRowBuffer();
    }
    
    
    /**
     * Clear the update row or insert row buffer.
     */
    private void clearRowBuffer(){
        if(values != null){
            for(int i=values.length-1; i>=0; i--){
                values[i].clear();
            }
        }
    }
    

    public void moveToInsertRow() throws SQLException {
    	if(isUpdatable){
    		isInsertRow = true;
            clearRowBuffer();
    	}else{
            throw SmallSQLException.create(Language.RSET_READONLY);
    	}
    }
    
    
    public void moveToCurrentRow() throws SQLException{
		isInsertRow = false;
        clearRowBuffer();
        if(values == null){
            //init the values array as insert row buffer 
            getUpdateValue(1);
        }
    }
    
    
    public Statement getStatement() {
        return st;
    }
    
    
    public Object getObject(int i, Map map) throws SQLException {
        return getObject( i );
    }
    
    
    public Ref getRef(int i) throws SQLException {
        /**@todo: Implement this java.sql.ResultSet.getRef method*/
        throw SmallSQLException.create(Language.UNSUPPORTED_OPERATION, "Ref object");
    }
    
    
    public Blob getBlob(int i) throws SQLException {
        /**@todo: Implement this java.sql.ResultSet.getBlob method*/
        throw SmallSQLException.create(Language.UNSUPPORTED_OPERATION, "Blob object");
    }
    
    
    public Clob getClob(int i) throws SQLException {
        /**@todo: Implement this java.sql.ResultSet.getClob method*/
        throw SmallSQLException.create(Language.UNSUPPORTED_OPERATION, "Clob object");
    }
    
    
    public Array getArray(int i) throws SQLException {
        /**@todo: Implement this java.sql.ResultSet.getArray method*/
        throw SmallSQLException.create(Language.UNSUPPORTED_OPERATION, "Array");
    }
    
    
    public Object getObject(String columnName, Map map) throws SQLException {
        return getObject( columnName );
    }
    public Ref getRef(String columnName) throws SQLException {
        return getRef( findColumn( columnName ) );
    }
    public Blob getBlob(String columnName) throws SQLException {
        return getBlob( findColumn( columnName ) );
    }
    public Clob getClob(String columnName) throws SQLException {
        return getClob( findColumn( columnName ) );
    }
    public Array getArray(String columnName) throws SQLException {
        return getArray( findColumn( columnName ) );
    }
    
    
    public Date getDate(int columnIndex, Calendar cal) throws SQLException {
        try{
            if(cal == null){
                return getDate(columnIndex);
            }
            Expression expr = getValue(columnIndex);
            wasNull = expr.isNull();
            if(wasNull) return null;
            return new Date(DateTime.addDateTimeOffset( expr.getLong(), cal.getTimeZone() ));
        }catch(Exception e){
            throw SmallSQLException.createFromException( e );
        }
    }
    
    
    public Date getDate(String columnName, Calendar cal) throws SQLException {
        return getDate( findColumn( columnName ), cal );
    }
    
    
    public Time getTime(int columnIndex, Calendar cal) throws SQLException {
        try{
            if(cal == null){
                return getTime(columnIndex);
            }
            Expression expr = getValue(columnIndex);
            wasNull = expr.isNull();
            if(wasNull) return null;
            return new Time(DateTime.addDateTimeOffset( expr.getLong(), cal.getTimeZone() ));
        }catch(Exception e){
            throw SmallSQLException.createFromException( e );
        }
    }
    
    
    public Time getTime(String columnName, Calendar cal) throws SQLException {
        return getTime( findColumn( columnName ), cal );
    }
    
    
    public Timestamp getTimestamp(int columnIndex, Calendar cal) throws SQLException {
        try{
            if(cal == null){
                return getTimestamp(columnIndex);
            }
            Expression expr = getValue(columnIndex);
            wasNull = expr.isNull();
            if(wasNull) return null;
            return new Timestamp(DateTime.addDateTimeOffset( expr.getLong(), cal.getTimeZone() ));
        }catch(Exception e){
            throw SmallSQLException.createFromException( e );
        }
    }
    
    
    public Timestamp getTimestamp(String columnName, Calendar cal) throws SQLException {
        return getTimestamp( findColumn( columnName ), cal );
    }
    
    
    public URL getURL(int columnIndex) throws SQLException {
        try{
            Expression expr = getValue(columnIndex);
            wasNull = expr.isNull();
            if(wasNull) return null;
            return new URL( expr.getString() );
        }catch(Exception e){
            throw SmallSQLException.createFromException( e );
        }
    }
    
    
    public URL getURL(String columnName) throws SQLException {
        return getURL( findColumn( columnName ) );
    }
    
    
    public void updateRef(int columnIndex, Ref x) throws SQLException {
        /**@todo: Implement this java.sql.ResultSet.updateRef method*/
        throw SmallSQLException.create(Language.UNSUPPORTED_OPERATION, "Ref");
    }
    
    
    public void updateRef(String columnName, Ref x) throws SQLException {
        updateRef( findColumn( columnName ), x );
    }
    
    
    public void updateBlob(int columnIndex, Blob x) throws SQLException {
        /**@todo: Implement this java.sql.ResultSet.updateBlob method*/
        throw SmallSQLException.create(Language.UNSUPPORTED_OPERATION, "Blob");
    }
    
    
    public void updateBlob(String columnName, Blob x) throws SQLException {
        updateBlob( findColumn( columnName ), x );
    }
    
    
    public void updateClob(int columnIndex, Clob x) throws SQLException {
        /**@todo: Implement this java.sql.ResultSet.updateClob method*/
        throw SmallSQLException.create(Language.UNSUPPORTED_OPERATION, "Clob");
    }
    
    
    public void updateClob(String columnName, Clob x) throws SQLException {
        updateClob( findColumn( columnName ), x );
    }
    
    
    public void updateArray(int columnIndex, Array x) throws SQLException {
        /**@todo: Implement this java.sql.ResultSet.updateArray method*/
        throw SmallSQLException.create(Language.UNSUPPORTED_OPERATION, "Array");
    }
    
    
    public void updateArray(String columnName, Array x) throws SQLException {
        updateArray( findColumn( columnName ), x );
    }
    
	/*========================================================

	private methods

	=========================================================*/

    /**
     * Get the expression of a column. 
     * This expression can be used to request a value of the current row.
     */
    final private Expression getValue(int columnIndex) throws SQLException{
        if(values != null){
            ExpressionValue value = values[ metaData.getColumnIdx( columnIndex ) ];
            if(!value.isEmpty() || isInsertRow){ 
                return value;
            }
        }
        return metaData.getColumnExpression(columnIndex);
    }
    

	final private ExpressionValue getUpdateValue(int columnIndex) throws SQLException{
		if(values == null){
			int count = metaData.getColumnCount();
			values = new ExpressionValue[count];
			while(count-- > 0){
				values[count] = new ExpressionValue();
			}
		}
		return values[ metaData.getColumnIdx( columnIndex ) ];
	}
	
    
    final private void updateValue(int columnIndex, Object x, int dataType) throws SQLException{
		getUpdateValue( columnIndex ).set( x, dataType );
		if(st.con.log.isLogging()){
			
			st.con.log.println("parameter '"+metaData.getColumnName(columnIndex)+"' = "+x+"; type="+dataType);
		}
    }
    
    
	final private void updateValue(int columnIndex, Object x, int dataType, int length) throws SQLException{
		getUpdateValue( columnIndex ).set( x, dataType, length );
		if(st.con.log.isLogging()){
			st.con.log.println("parameter '"+metaData.getColumnName(columnIndex)+"' = "+x+"; type="+dataType+"; length="+length);
		}
	}


	final private CommandSelect getCmd() throws SQLException {
		if(cmd == null){
            throw SmallSQLException.create(Language.RSET_CLOSED);
        }
        st.con.testClosedConnection();
		return cmd;
	}
}