CREATE TABLE Customer(
Cust_Id Number(4),
Cust_First_Name VarChar2(20),
Cust_Mid_Name VarChar2(20),
Cust_Last_Name VarChar2(20),
Account_Type Varchar2(15),
Cust_Email VarChar2(30),
Cust_Mobile Number(10),
Bank_Id NUMBER(4),
Account_No Number(4),
CONSTRAINT Cust_Id_Pri_Key PRIMARY KEY (Cust_Id),
CONSTRAINT Cust_Last_Name_Not_Null NOT NULL (Cust_Last_Name),
CONSTRAINT Cust_First_Name_Not_Null NOT NULL (Cust_First_Name),
CONSTRAINT Cust_Email_Unq UNIQUE(Cust_Email),
CONSTRAINT Cust_Mobile_Unq UNIQUE(Cust_Mobile),
CONSTRAINT Bank_Id_For_Key FOREIGN KEY REFERENCES bank(bankId)
);
答案 0 :(得分:2)
以下是SQL的外观。
CREATE TABLE Customer(
Cust_Id Number(4) NOT NULL,
Cust_First_Name VarChar2(20) NOT NULL,
Cust_Mid_Name VarChar2(20),
Cust_Last_Name VarChar2(20) NOT NULL,
Account_Type Varchar2(15),
Cust_Email VarChar2(30),
Cust_Mobile Number(10),
Bank_Id NUMBER(4),
Account_No Number(4),
CONSTRAINT Cust_Id_Pri_Key PRIMARY KEY (Cust_Id),
CONSTRAINT Cust_Email_Unq UNIQUE(Cust_Email),
CONSTRAINT Cust_Mobile_Unq UNIQUE(Cust_Mobile),
CONSTRAINT Bank_Id_For_Key FOREIGN KEY (Bank_Id) REFERENCES bank(bankId)
);
几乎所有错误都来自语法。
NOT NULL
在列名称中指定,而不是单独的约束。FOREIGN KEY CONSTRAINT requires you to specify the source column name, and the
FOREIGN KEY column in the table that it is defined as a
PRIMARY KEY` 答案 1 :(得分:0)
您有两个问题:您无法将NOT NULL
指定为外联约束,并且您在外键约束中缺少列名。以下应该有效:
CREATE TABLE customer
(
cust_id NUMBER (4),
cust_first_name VARCHAR2 (20) CONSTRAINT cust_first_name_not_null NOT NULL,
cust_mid_name VARCHAR2 (20),
cust_last_name VARCHAR2 (20) CONSTRAINT cust_last_name_not_null NOT NULL,
account_type VARCHAR2 (15),
cust_email VARCHAR2 (30),
cust_mobile NUMBER (10),
bank_id NUMBER (4),
account_no NUMBER (4),
CONSTRAINT cust_id_pri_key PRIMARY KEY (cust_id),
CONSTRAINT cust_email_unq UNIQUE (cust_email),
CONSTRAINT cust_mobile_unq UNIQUE (cust_mobile),
CONSTRAINT bank_id_for_key FOREIGN KEY (bank_id) REFERENCES bank (bankid)
);
但是,我不会为命名NOT NULL
约束而烦恼。命名它们并没有真正增加可管理性,因为它们可以通过在不知道名称的情况下更改表来更新。