Method makeNullString

src/common/dsc.h:401–410

	}

	void makeNullString()
	{
		clear();

		// CHAR(1) CHARACTER SET NONE
		dsc_dtype = dtype_text;
		setTextType(CS_NONE);
		dsc_length = 1;
		dsc_flags = DSC_nullable | DSC_null;
	}

	void makeShort(SCHAR scale, SSHORT* address = NULL)
	{