办公自动化(综合版)
辦公自動化(綜閤版)
판공자동화(종합판)
OFFICE AUTOMATION
2013年
2期
50-51
,共2页
派生表%SQL查询语句%效率
派生錶%SQL查詢語句%效率
파생표%SQL사순어구%효솔
Derived table%SQL query%Efficiency
派生表是将子查询作为一个表来处理,使子查询的效率大大提高.本文从如何正确使用派生表出发,阐述了在SQL查询语句中如何合理运用派生表来提高查询效率.
派生錶是將子查詢作為一箇錶來處理,使子查詢的效率大大提高.本文從如何正確使用派生錶齣髮,闡述瞭在SQL查詢語句中如何閤理運用派生錶來提高查詢效率.
파생표시장자사순작위일개표래처리,사자사순적효솔대대제고.본문종여하정학사용파생표출발,천술료재SQL사순어구중여하합리운용파생표래제고사순효솔.
Derived table is sub query as a table processing. It can greatly improve the efficiency of sub query. In this paper how to correctly use the derived table set,the paper describes in the SQL query how reasonable use derived table to improve the query efficiency.