小编mee*_*shi的帖子

CREATE TABLE pledge
(
    pledge_ID            NUMBER NOT NULL ,
    pledge_endDate       DATE NULL ,
    pledge_startDate     DATE NULL  ,
    pledge_amount        DECIMAL(9,2) NULL  CONSTRAINT  Currency_1322638346 CHECK (pledge_amount >= 0),
    artist_userID        NUMBER NOT NULL,
    follower_userID      NUMBER NOT NULL, 
CONSTRAINT  XPKPledge PRIMARY KEY (pledge_ID),
CONSTRAINT gets FOREIGN KEY (artist_userID) REFERENCES ArtistMember (user_ID),
CONSTRAINT makes FOREIGN KEY (follower_userID) REFERENCES FollowerMember (user_ID)
);

当我尝试插入空值时，出现以下错误。

INSERT INTO pledge VALUES(559, 'null','1-FEB-2016', 3850, 85275, 88128);

Error report -
SQL Error: ORA-00904: : invalid identifier
00904. 00000 -  "%s: invalid identifier" …

CREATE TABLE Member
(
    user_ID              NUMBER NOT NULL ,
    user_password        VARCHAR2(50) NULL  CONSTRAINT  Email_153906048 CHECK (user_password IN ('%@%')),
    user_email           VARCHAR2(50) NULL  CONSTRAINT  Email_1275780631 CHECK (user_email IN ('%@%')),
    user_firstName       VARCHAR2(20) NULL ,
    user_lastName        VARCHAR2(20) NULL ,
    user_type            VARCHAR2(8) NULL  CONSTRAINT  Type_1346517516 CHECK (user_type IN ('Artist', 'Follower')),
CONSTRAINT  XPKUser PRIMARY KEY (user_ID)
);