IT_民工

1.当在开发测试时，误删除数据，如想恢复，可立即alter table table_name enable row movement;flashback table table_name to timestampto_timestamp('2008070816','yyyymmddhh24');...

SQL： select g.registertime, decode(sum(inner), null, 0, sum(inner)) inner, decode(sum(outer), null, 0, sum(outer)) outer from( SELECT t.registertime, case WHEN ...