Oracle SQL检查错误

为什么在使用检查约束时命令不起作用？当不包括支票时，可以添加该表

 create table Car (
      CarID           number(32,0) NOT NULL ,
      PurchaseDate  date,
      Colour  varchar2(10) NOT NULL CHECK (Colour IN ("Red", "Blue", "Green")),
      CONSTRAINT CAR_PK PRIMARY KEY (CarID),
      FOREIGN KEY (CarID) REFERENCES Vehicle(ID)

    );

Error report -
SQL Error: ORA-02438: Column check constraint cannot reference other columns
02438. 00000 -  "Column check constraint cannot reference other columns"
*Cause:    attempted to define a column check constraint that references
           another column.
*Action:   define it as a table check constriant.

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oracle SQL中不允许使用双引号

尝试购买日期日期到PurchaseDate Date Date Date不是问题使用单引号而不是双引号表示状态文字。它应该是

检查（颜色在
中），
不检查（状态在
中）和单引号而不是双引号这是引号造成的。谢谢
 create table Car (
      CarID           number(32,0) NOT NULL ,
      PurchaseDate  date,
      Colour  varchar2(10) NOT NULL CHECK (Colour IN ('Red', 'Blue', 'Green')),
      CONSTRAINT CAR_PK PRIMARY KEY (CarID),
      FOREIGN KEY (CarID) REFERENCES Vehicle(ID)

    );