ORACLE中的五种约束

CREATE TABLE TABLENAMEEXAMLE(
   PRIMARYKEYFILED NUMBER(2) CONSTRAINT PK_ID PRIMARY KEY,
   NULLEXAMPLEFIELD VARCHAR2(8) NOT NULL,
   FOREIGNKEYFIELD NUMBER(2) CONSTRAINT FK_ID FOREIGN KEY(FOREIGNKEYFIELD) REFERENCES ANOTHERTABLE(PRIMARYKEYFIELDNAME),
   FILEDUNIQUEEXAMPLEFIELD VARCHAR2(64) UNIQUE,
   CHECKEXAMPLEFIELD NUMBER(7,2) CONSTRAINT CONSTRAINTNAME CHECK(CHECKEXAMPLEFIELD>0 AND CHECKEXAMPLEFIELD<=3000)

}