INSERT不起作用，在ORACLE中使用SQL PLUS，定义类型的简单表，完美创建但不插入值

Question

DROP TYPE Position;

CREATE OR REPLACE TYPE 
Position AS OBJECT
(longitude NUMBER(11,7),
lattitude NUMBER(11,7),
CONSTRUCTOR FUNCTION Position(
    long NUMBER,
    latt NUMBER
    ) RETURN SELF AS RESULT
)FINAL;
/


CREATE OR REPLACE TYPE BODY Position AS
CONSTRUCTOR FUNCTION Position(
    long NUMBER,
    latt NUMBER
    ) RETURN SELF AS RESULT IS
  BEGIN
      SELF.longitude := long;
      SELF.lattitude := latt;
  RETURN;
  END;

END;
/

DESC Position;


DROP TABLE District_Info;

CREATE TABLE District_Info(
Dname VARCHAR2(20),
DPos Position,
Boundary_dist VARCHAR2(20),
Launch_ghat CHAR(1)
);

DESC District_Info;


INSERT INTO District_Info (Dname,DPos,Boundary_dist,Launch_ghat)
VALUES ('d',Position(1.1, 1.1),'gr','y');

Answer 1

您的问题是您定义了两个相同类型的构造函数，但您没有意识到您可能这样做了。

当您创建对象类型时，Oracle 会创建一个默认构造函数，其参数与该类型的参数相匹配。因此，当您还定义了一个仅以纬度和经度作为输入的构造函数时，Oracle 无法确定要调用哪个构造函数、默认创建的构造函数还是您的构造函数，因此会出现错误：

SQL Error: ORA-06553: PLS-307: too many declarations of 'POSITION' match this call

要解决此问题，您可以简化代码：

drop type position;

CREATE OR REPLACE TYPE Position AS OBJECT (longitude NUMBER(11,7), lattitude NUMBER(11,7))
/

DROP TABLE District_Info;

CREATE TABLE District_Info( Dname VARCHAR2(20), DPos Position, Boundary_dist VARCHAR2(20), Launch_ghat CHAR(1) );


INSERT INTO District_Info (Dname,DPos,Boundary_dist,Launch_ghat) VALUES ('d',Position(1.1),'gr','y');

即，您不需要构造函数声明或主体。如果你愿意，你可以有一个不同的构造函数，例如：

CREATE OR REPLACE TYPE Position AS OBJECT (longitude NUMBER(11,7), lattitude NUMBER(11,7),
-- Define a constructor that has only 2 parameters.
  CONSTRUCTOR FUNCTION position(i_longitude NUMBER)
    RETURN SELF AS RESULT
)
/

CREATE OR REPLACE TYPE BODY Position AS 
  CONSTRUCTOR FUNCTION position(i_longitude NUMBER)
    RETURN SELF AS RESULT IS 
  BEGIN 
    SELF.longitude := i_longitude; 
    SELF.lattitude := i_longitude; 
    RETURN; -- self; 
  END;
END; 
/

show errors;

DROP TABLE District_Info;

CREATE TABLE District_Info( Dname VARCHAR2(20), DPos Position, Boundary_dist VARCHAR2(20), Launch_ghat CHAR(1) );

DESC District_Info;

INSERT INTO District_Info (Dname,DPos,Boundary_dist,Launch_ghat) VALUES ('d',Position(1.1),'gr','y');