摘要:
DDL操作建表语句:create table(column列 datatype数据类型 constraint约束) 列级约束: CREATE TABLE BOOKS(BK_ID NUMBER (4) CONSTRAINT BK_PK PRIMARY KEY (BK_ID),BK_TITLE VARCHAR(50) NOT NULL, BK_DESC VARCHAR(50)); 表级约束:CREATE TABLE BOOKS( BK_ID NUMBER (4) NOT NULL, BK_TITLE VARCHAR(50) NOT NULL, BK_DESC VARCHAR(50), CONSTR 阅读全文
posted @ 2013-06-04 11:29
turnhopes
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