摘要:
在Oracle中,要按特定条件查询前N条记录,用个rownum就搞定了。select * from emp where rownum ",这也就意味着,如果你想用select * from emp where rownum > 5则是失败的。要知道为什么会失败,则需要了解rownum背后的机制:1 Oracle executes your query.2 Oracle fetches the first row and calls it row number 1.3 Have we gotten past row number meets the criteria? If no 阅读全文