如何在 PL/SQL 对象类型中链接成员函数

Question

对于我想要完成的事情来说，这可能是一个糟糕的用例，但我已经阅读了几十页，但我无法弄清楚这在 Oracle 中是否可行。

我想完成与另一个 Whosebug 问题类似的事情：How to chain calls in a pl/sql object type of functions returning SELF

在我的代码中，我有一个名为 parseName 的类型，它带有构造函数和 3 个成员函数：getFirstName、getMiddleName、getLastName。我想要第四个成员函数：cleanString，它删除不在 A-Z 或 a-z 之间的所有字符。

调用示例：

SELECT parseName('John123 Doe').getFirstName().cleanString()
FROM dual;

SELECT parseName('John123 Doe').getFirstName()
FROM dual;

这是我目前所写的类型。

CREATE OR REPLACE TYPE parseName AS OBJECT
(
    g_name         VARCHAR2(255),
    g_parts        NUMBER,
    g_first_name   VARCHAR2(255),
    g_middle_name  VARCHAR2(1),
    g_last_name    VARCHAR2(255),
    -- constructor function
    CONSTRUCTOR FUNCTION parseName
      (p_name IN VARCHAR2)
      RETURN self AS result,
    -- member functions
    MEMBER FUNCTION getFirstName  RETURN VARCHAR2,
    MEMBER FUNCTION getMiddleName RETURN VARCHAR2,
    MEMBER FUNCTION getLastName   RETURN VARCHAR2
);
/
SHOW ERRORS
/

CREATE OR REPLACE TYPE BODY parseName IS

  -- populateValues
  CONSTRUCTOR FUNCTION parseName
    (p_name IN VARCHAR2)
  RETURN self AS result
  IS
    -- other variables
    v_name    VARCHAR2(255);
    v_length  NUMBER;
    v_parts   NUMBER;
    v_instr   NUMBER;
  BEGIN

    -- save off input
    v_name := TRIM(p_name);

    -- check
    IF v_name IS NULL THEN
      self.g_first_name  := 'Unknown';
      self.g_middle_name := ' ';
      self.g_last_name   := 'Unknown';
      RETURN;
    END IF;

    -- otherwise, fill our global
    self.g_name := v_name;

    -- exit
    RETURN;

  END;

  /* getFirstName */
  /* --------------------------------------- */
  MEMBER FUNCTION getFirstName
    RETURN VARCHAR2
  IS
    v_parts NUMBER;
  BEGIN

    -- did we get a null on construct?
    IF self.g_first_name IS NOT NULL THEN
      RETURN self.g_first_name;
    END IF;

    -- how many spaces do we have?
    v_parts := LENGTH(self.g_name) - LENGTH(REPLACE(self.g_name,' ',''));

    -- if 0 spaces, return the name
    IF v_parts = 0 THEN
      RETURN self.g_name;
    -- else, return everything up to the space
    ELSE
      RETURN TRIM(SUBSTR(self.g_name,1, INSTR(self.g_name,' ',1) ));
    END IF;

  END getFirstName;

  /* getMiddleName */
  /* --------------------------------------- */
  MEMBER FUNCTION getMiddleName
    RETURN VARCHAR2
  IS
    v_parts  NUMBER;
    v_instr2 NUMBER;
    v_instr1 NUMBER;
  BEGIN

    -- did we get a null on construct?
    IF self.g_middle_name IS NOT NULL THEN
      RETURN NULL;
    END IF;

    -- how many spaces do we have?
    v_parts := LENGTH(self.g_name) - LENGTH(REPLACE(self.g_name,' ',''));

    -- if we have zero spaces, we only have a first name, return null
    IF v_parts = 0 THEN
      RETURN NULL;
    -- don't do middle if we only have 1 space
    ELSIF v_parts = 1 THEN
      RETURN NULL;
    -- else, we've got more than one, so grab between space 1 and 2
    ELSE
      v_instr2 := INSTR(self.g_name,' ',1,2);
      v_instr1 := INSTR(self.g_name,' ',1,1);
      RETURN TRIM( SUBSTR(self.g_name, v_instr1, (v_instr2-v_instr1) ));
    END IF;

  END getMiddleName;

  /* getLastName */
  /* --------------------------------------- */
  MEMBER FUNCTION getLastName
    RETURN VARCHAR2
  IS
    v_parts  NUMBER;
  BEGIN

    -- did we get a null on construct?
    IF self.g_last_name IS NOT NULL THEN
      RETURN self.g_last_name;
    END IF;

    -- how many spaces do we have?
    v_parts := LENGTH(self.g_name) - LENGTH(REPLACE(self.g_name,' ',''));

    -- if we have zero spaces, we only have a first name, return 'Unknown'
    IF v_parts = 0 THEN
      RETURN 'Unknown';
    -- if have 1 space, the space on is the last name
    ELSIF v_parts = 1 THEN
      RETURN TRIM( SUBSTR(self.g_name, INSTR(self.g_name,' ',1,1), LENGTH(self.g_name)) );
    -- else, we've got more than one, go from 2 to end
    ELSE
      RETURN TRIM( SUBSTR(self.g_name, INSTR(self.g_name,' ',1,2), LENGTH(self.g_name)) );
    END IF;

  END getLastName;


END;
/
SHOW ERRORS
/

.

感谢您提供的任何建议。

Answer 1

I would like to have a fourth member function called: cleanString which removes all characters not between A-Z or a-z.

Example calls:
SELECT parseName('John123 Doe').getFirstName().cleanString()
FROM dual;

当你调用 .getFirstName() 时，期望的是它 return 人的名字（毕竟这是成员函数的名字所说的）并且名字是 VARCHAR2数据类型。 VARCHAR2 是原始数据类型，不是您可以（以某种方式）扩展为具有 .cleanString() 成员函数的对象。

您可以定义一个 cleanString() 函数：

CREATE FUNCTION cleanString( value VARCHAR2 ) RETURN VARCHAR2
IS
BEGIN
  RETURN REGEXP_REPLACE( value, '[^[:alpha:]]+' );
END cleanString;
/

然后调用：

 SELECT cleanString( parseName('John123 Doe').getFirstName() )
 FROM   DUAL;

或者你可以创建一个成员函数来在 return 之前清理名称：

SQL Fiddle

Oracle 11g R2 架构设置:

CREATE OR REPLACE TYPE parseName AS OBJECT
(
    g_name         VARCHAR2(255),
    g_first_name   VARCHAR2(255),
    g_middle_name  VARCHAR2(1),
    g_last_name    VARCHAR2(255),
    -- constructor function
    CONSTRUCTOR FUNCTION parseName(p_name IN VARCHAR2) RETURN self AS result,
    -- member functions
    MEMBER FUNCTION cleanNames    RETURN parseName,
    MEMBER FUNCTION getFirstName  RETURN VARCHAR2,
    MEMBER FUNCTION getMiddleName RETURN VARCHAR2,
    MEMBER FUNCTION getLastName   RETURN VARCHAR2
);
/

CREATE OR REPLACE TYPE BODY parseName IS
  -- populateValues
  CONSTRUCTOR FUNCTION parseName(p_name IN VARCHAR2) RETURN self AS result
  IS
  BEGIN
    g_name := TRIM(p_name);
    g_first_name  := REGEXP_SUBSTR( g_name, '^(\S+)\s+((\S*?)\s+)?(.*)$', 1, 1, NULL, 1 );
    g_middle_name := REGEXP_SUBSTR( g_name, '^(\S+)\s+((\S*?)\s+)?(.*)$', 1, 1, NULL, 3 );
    g_last_name   := REGEXP_SUBSTR( g_name, '^(\S+)\s+((\S*?)\s+)?(.*)$', 1, 1, NULL, 4 );
    RETURN;
  END;

  MEMBER FUNCTION cleanNames RETURN parseName
  IS
    v_name parseName := SELF;
  BEGIN
    v_name.g_first_name  := cleanString( SELF.g_first_name );
    v_name.g_middle_name := cleanString( SELF.g_middle_name );
    v_name.g_last_name   := cleanString( SELF.g_last_name );
    RETURN v_name;
  END;

  MEMBER FUNCTION getFirstName RETURN VARCHAR2
  IS
  BEGIN
    RETURN g_first_name;
  END getFirstName;

  MEMBER FUNCTION getMiddleName RETURN VARCHAR2
  IS
  BEGIN
    RETURN g_middle_name;
  END getMiddleName;

  MEMBER FUNCTION getLastName RETURN VARCHAR2
  IS
  BEGIN
    RETURN g_last_name;
  END getLastName;
END;
/

查询 1:

SELECT parseName('John123 Doe').getFirstName(),
       parseName('John123 Doe').cleanNames().getFirstName()
FROM DUAL

Results:

| PARSENAME('JOHN123DOE').GETFIRSTNAME() | PARSENAME('JOHN123DOE').CLEANNAMES().GETFIRSTNAME() |
|----------------------------------------|-----------------------------------------------------|
|                                John123 |                                                John |

如何在 PL/SQL 对象类型中链接成员函数

How to Chain Member Functions in a PL/SQL Object Type

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