oracle鍵約束控制

約束

1.define constraints as immediate or deferred sql> alter session set constraint[s] = immediate/deferred/default; set constraint[s] constraint_name/all immediate/deferred; 2. sql> drop table table_name cascade constraints sql> drop tablespace tablespace_name including contents cascade constraints 3. define constraints while create a table sql> create table xay(id number(7) constraint xay_id primary key deferrable sql> using index storage(initial 100k next 100k) tablespace indx); primary key/unique/references table(column)/check 4.enable constraints sql> alter table xay enable novalidate constraint xay_id; 5.enable constraints sql> alter table xay enable validate constraint xay_id;

[@more@]