1.增加主键 alter table TABLE_NAME add constraint KEY_NAME primary key (TABLE_COLUMN); 指定表空间 alter table TABLE_NAME add constraint KEY_NAME primary key (TABLE_COLUMN) using index tablespace TABLE_SPACE_NAME;2.增加外键 alter table TABLE_NAME add constraint FK_NAME foreign key (TABLE_COLUMN) references KEY_TABLE_NAME;3.使主键或外键失效、生效 alter table TABLE_NAME disable(enable) constraint KEY_NAME;4、查看各种约束 select constraint_name,table_name,constraint_type,status from user_constraints; select constraint_name, constraint_type,search_condition, r_constraint_name from user_constraints where table_name = upper('&table_name') select c.constraint_name,传奇外传sf,c.constraint_type,cc.column_name from user_constraints c,魔兽私服,user_cons_columns cc where c.owner = upper('&table_owner') and c.table_name = upper('&table_name') and c.owner = cc.owner and c.constraint_name = cc.constraint_name order by cc.position; 5、删除主键或外键 alter table TABLE_NAME drop constraint KEY_NAME;6、建外键 单字段时：create table 表名 (col1 char(8),魔域私服, cno char(4) REFERENCE course); 多个字段时,劲舞团私服,在最后加上 Foreign Key (字段名) REFERENCE 表名(字段) 连带删除选项 (on delete cascade 当指定时，如果父表中的记录被删除,1.76复古传奇，则依赖于父表的记录也被删除 REFERENCE 表名（） on delete cascade;7、删除带约束的表 Drop table 表名 cascade constraints; 8：索引管理<1>.creating function-based indexessql> create index summit.item_quantity on summit.item(quantity-quantity_shipped); <2>.create a B-tree indexsql> create [unique] index index_name on table_name(column,.. asc/desc) tablespacesql> tablespace_name [pctfree integer] [initrans integer] [maxtrans integer]sql> [logging nologging] [nosort] storage(initial 200k next 200k pctincrease 0sql> maxextents 50); <3>.pctfree(index)=(maximum number of rows-initial number of rows)*100/maximum number of rows <4>.creating reverse key indexessql> create unique index xay_id on xay(a) reverse pctfree 30 storage(initial 200ksql> next 200k pctincrease 0 maxextents 50) tablespace indx; <5>.create bitmap indexsql> create bitmap index xay_id on xay(a) pctfree 30 storage( initial 200k next 200ksql> pctincrease 0 maxextents 50) tablespace indx; <6>.change storage parameter of indexsql> alter index xay_id storage (next 400k maxextents 100); 7.allocating index space
