數(shù)據(jù)字典總結(jié)(oracle10g)(編輯修改稿)
2025-07-14 06:32 本頁面
【文章內(nèi)容簡介】 設(shè)置日期的顯示格式的方法SQLalter session set NLS_date_formate=39。ddmonyyyy hh:mi:ss39。20 query current database instance查看當(dāng)前的數(shù)據(jù)庫實例名SQLselect instance_name from v$instance。21 domain integrity operationSQLalter table tbname add constraint pk_tbname primary key(n1)22 referential integrity operation添加外鍵的語法SQLalter table emp add constraint constraint fk_tbname foreign key(n1)references tbname(n1) initially deferred deferrable23 Check operation添加check的語法SQLalter table emp add constraint ck_emp_agender check(agender=39。男39。or agender=39。女39。)24 Create a table through a subquery通過子查詢創(chuàng)建表的語法SQLcreate table emp_41 as select id, last_name, userid, start_date from s_emp where dept_id = 41。25 A plex example on table structure 復(fù)雜的表結(jié)構(gòu)SQL CREATE TABLE s_emp (id NUMBER(7) CONSTRAINT s_emp_id_pk PRIMARY KEY, last_name VARCHAR2(25) CONSTRAINT s_emp_last_name_nn NOT NULL, first_name VARCHAR2(25), userid VARCHAR2(8) CONSTRAINT s_emp_userid_nn NOT NULL CONSTRAINT s_emp_userid_uk UNIQUE, start_date DATE DEFAULT SYSDATE, ments VARCHAR2(25), manager_id NUM
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