如何使用substr函数验证过滤器，并从Oracle PLSQL中的存储过程中获取结果？

我创建了一个存储过程，在where子句中有两个过滤器。我已经包含了一个过滤器，并且能够得到结果。但是，当我尝试包含第二个过滤器时，该过程没有显示任何值

用户从UI屏幕输入参数并单击搜索按钮

UI屏幕：

   Procedure search_emp (  pt_id        in     number,
                        pt_name       in     varchar2,
                        pt_country    in     varchar2,
                        empCursor    out    ref cursor)

as

    v_countrycode           CHAR(2);
    v_count                 NUMBER;
begin

    SELECT count(*) INTO v_count FROM r_country where UPPER(country) = UPPER(pt_country); 
    IF v_count > 0 THEN        
    SELECT countrycode INTO v_countrycode FROM r_country where UPPER(country) = UPPER(pt_country);            
    ELSE NULL; 
    END IF;  -- here, am trying to get the country code from the table for the input parameter 'pt_country' that is passed.

    open empCursor for
    select e.emp_id,
    e.name,
    e.phone_number           
    from employee e
    where upper(e.emp_id)    = upper(pt_emp_id)
    and   (UPPER(substr(e.phone_number,1,2)) LIKE UPPER(v_countrycode) or pt_country IS NULL);

--- I'm not sure how to get the results when the User gives a value to the input parameter  'pt_country'.
END;

Emp ID:\uuuuuuuuuuuuuuuuuuuuuuuuuuu

国家：__________

                 Search button        Cancel button

数据来自Oracle数据库中名为Employee的表

员工表：

   Procedure search_emp (  pt_id        in     number,
                        pt_name       in     varchar2,
                        pt_country    in     varchar2,
                        empCursor    out    ref cursor)

as

    v_countrycode           CHAR(2);
    v_count                 NUMBER;
begin

    SELECT count(*) INTO v_count FROM r_country where UPPER(country) = UPPER(pt_country); 
    IF v_count > 0 THEN        
    SELECT countrycode INTO v_countrycode FROM r_country where UPPER(country) = UPPER(pt_country);            
    ELSE NULL; 
    END IF;  -- here, am trying to get the country code from the table for the input parameter 'pt_country' that is passed.

    open empCursor for
    select e.emp_id,
    e.name,
    e.phone_number           
    from employee e
    where upper(e.emp_id)    = upper(pt_emp_id)
    and   (UPPER(substr(e.phone_number,1,2)) LIKE UPPER(v_countrycode) or pt_country IS NULL);

--- I'm not sure how to get the results when the User gives a value to the input parameter  'pt_country'.
END;

Emp\u id----姓名------电话号码------国家

1----约翰·史密斯----US-765-234-4567----美国

2---Sam Benigal---AL-978-346-765----阿根廷

3----马克·泰勒----AS-987-3987-857----澳大利亚

4----克莱尔·弗纳---加拿大CA-85-454-5454

对于第二个过滤器，我需要使用包含以countrycode开头的数据的电话号码（“美国国家的US-765-234-4567”；阿根廷国家的“AR-978-346-765”；澳大利亚国家的“AS-987-3987-857…”等）并与输入参数“pt_country”匹配以生成结果。 我在这个场景中使用了Substring函数，因为根据电话号码中的前两个字符，我需要得到结果

此外，输入参数“pt_country”可以有值，也可以为空

代码：

   Procedure search_emp (  pt_id        in     number,
                        pt_name       in     varchar2,
                        pt_country    in     varchar2,
                        empCursor    out    ref cursor)

as

    v_countrycode           CHAR(2);
    v_count                 NUMBER;
begin

    SELECT count(*) INTO v_count FROM r_country where UPPER(country) = UPPER(pt_country); 
    IF v_count > 0 THEN        
    SELECT countrycode INTO v_countrycode FROM r_country where UPPER(country) = UPPER(pt_country);            
    ELSE NULL; 
    END IF;  -- here, am trying to get the country code from the table for the input parameter 'pt_country' that is passed.

    open empCursor for
    select e.emp_id,
    e.name,
    e.phone_number           
    from employee e
    where upper(e.emp_id)    = upper(pt_emp_id)
    and   (UPPER(substr(e.phone_number,1,2)) LIKE UPPER(v_countrycode) or pt_country IS NULL);

--- I'm not sure how to get the results when the User gives a value to the input parameter  'pt_country'.
END;

---

请提供帮助。

尝试以下步骤，需要将游标定义为SYS\u REFCURSOR以获取输出

   create or replace Procedure search_emp (  pt_emp_id        in     number,
                        pt_name       in     varchar2,
                        pt_country    in     varchar2,
                        empCursor    out    SYS_REFCURSOR)

as

    v_countrycode           CHAR(2);
    v_count                 NUMBER;
begin

    SELECT count(*) INTO v_count FROM r_country where UPPER(country) = UPPER(pt_country); 
    IF v_count > 0 THEN        
    SELECT countrycode INTO v_countrycode FROM r_country where UPPER(country) = UPPER(pt_country);            
    ELSE NULL; 
    END IF;  -- here, am trying to get the country code from the table for the input parameter 'pt_country' that is passed.

    open empCursor for
    select e.emp_id,
    e.name,
    e.phone_number           
    from employee e
    where upper(e.emp_id)    = upper(pt_emp_id)
    and   (UPPER(substr(e.phone_number,1,2)) LIKE UPPER(v_countrycode) or pt_country IS NULL);

--- I'm not sure how to get the results when the User gives a value to the input parameter  'pt_country'.
END;

---

使用单个查询获得以下结果：

Select e.emp_id,
    e.name,
    e.phone_number           
from employee e
Join r_country c 
  On (e.phone_number like c.countrycode || '-%')
Where upper(e.emp_id)    = upper(pt_emp_id)
  And UPPER(c.country) = UPPER(COALESCE(pt_country, c.COUNTRY))

---

干杯

另外，输入参数在调用pt_id和使用inside block时不同，因为pt_emp_idI尝试了上述两种解决方案。但是，它们不起作用。请帮忙！在UI中没有任何概念。。但是当我在后端运行这个过程时，我能够得到结果，代码运行得很好。但是，表中countrycode列存在数据问题，导致筛选器无法工作。有些国家代码有空格。谢谢kanagraj和Tejash的回复。