摘要:
由一个sql引发的思考: select * from z_test1 where id <> '' 先说结果:在oracle中啥也查不出来原因是:oracle中对空串都会视为NULL处理,如上sql等同于 select * from z_test1 where id <> NULL 但是对NULL执 阅读全文
摘要:
1、connect by 是结构化查询中用到的,其基本语法是:select … from tablename start with 条件1connect by 条件2where 条件3;例:select * from tablestart with org_id = ‘HBHqfWGWPy’conn 阅读全文