The two cursors both enable scrolling, which lets you move around within a cursor & forward and reverse, in both a relative and an absolute sense. 两类游标都将启用滚动,滚动将使您可以在游标内相对和绝对地向前移动和向后移动。
Cursor library not capable. Forward only cursors must be read only 游标库不可用。仅向前游标必须为只读