Question

我试图在CLOB变量中传递单个INTEGER列的值，以便可以执行IN操作（列输出的大小未知），但是出现错误，现在卡住了。首先，我试图在IN之后使用SELECT语句，但是我发现它在PL / SQL中不起作用。因此，简而言之，我希望能够检查表中的主键，如果不存在该主键，请使用新值更新现有记录，但是如果已经存在，则无法执行该操作。

DoGood Donor应用程序包含一个页面，该页面允许管理员在DD_DONOR中更改分配给捐赠者的ID 表。创建一个PL / SQL块来处理此任务。包括异常处理代码，以解决尝试通过输入重复的捐赠者ID。如果发生此错误，则显示消息 “此ID已被分配。”通过更改供体ID 305来测试代码。

这是我使用的桌子。 DD_DONOR

Name      Null?    Type         
--------- -------- ------------ 
IDDONOR   NOT NULL NUMBER(4)    
FIRSTNAME          VARCHAR2(15) 
LASTNAME           VARCHAR2(30) 
TYPECODE           CHAR(1)      
STREET             VARCHAR2(40) 
CITY               VARCHAR2(20) 
STATE              CHAR(2)      
ZIP                VARCHAR2(9)  
PHONE              VARCHAR2(10) 
FAX                VARCHAR2(10) 
EMAIL              VARCHAR2(25) 
NEWS               CHAR(1)      
DTENTERED          DATE

这是我的代码：

DECLARE
    all_ids clob;
    newID DD_DONOR.IDDONOR%TYPE;
    fname DD_DONOR.FIRSTNAME%TYPE;
    lname DD_DONOR.LASTNAME%TYPE;    
    CURSOR id IS
    SELECT IDDONOR FROM DD_DONOR;   
BEGIN
    newID := 305;
    fname := 'Thomas';
    lname := 'Sheer';
    
    OPEN id;
    FETCH id BULK COLLECT INTO all_ids;

    IF id%NOTFOUND THEN
        UPDATE DD_DONOR
        SET IDDONOR = newID
        WHERE FIRSTNAME = fname AND LASTNAME = lname;
            DBMS_OUTPUT.PUT_LINE(fname || ' ' || lname || ' ' || 'New ID: ' || newID);
    ELSIF id%FOUND THEN
            DBMS_OUTPUT.PUT_LINE('This ID is already assigned.');
    END IF;

    CLOSE id;
END;

这是错误：

Error report -
ORA-06550: line 14, column 32:
PLS-00497: cannot mix between single row and multi-row (BULK) in INTO list
06550. 00000 -  "line %s, column %s:\n%s"
*Cause:    Usually a PL/SQL compilation error.

我在开始时创建的这段代码可以编译，但是对表没有任何作用，所以我放弃了它：

DECLARE
    newID DD_DONOR.IDDONOR%TYPE;
    fname DD_DONOR.FIRSTNAME%TYPE;
    lname DD_DONOR.LASTNAME%TYPE;
    
BEGIN
    newID := 305;
    fname := 'Thomas';
    lname := 'Sheer';
    
    UPDATE DD_DONOR
    SET IDDONOR = newID
    WHERE NOT EXISTS (SELECT IDDONOR
                      FROM DD_DONOR
                      WHERE FIRSTNAME = fname AND LASTNAME = lname);
    EXCEPTION 
        WHEN OTHERS THEN
        DBMS_OUTPUT.PUT_LINE('This ID is already assigned.');
END;

输出：

PL/SQL procedure successfully completed.

另一个无效的版本：

DECLARE
    newID DD_DONOR.IDDONOR%TYPE;
    fname DD_DONOR.FIRSTNAME%TYPE;
    lname DD_DONOR.LASTNAME%TYPE;
    
BEGIN
    newID := 305;
    fname := 'Thomas';
    lname := 'Sheer';
    
    IF (SELECT IDDONOR FROM DD_DONOR
        WHERE FIRSTNAME = fname AND LASTNAME = lname) = newID
        THEN 
        DBMS_OUTPUT.PUT_LINE('This ID is already assigned.');
    ELSE
        UPDATE DD_DONOR
        SET IDDONOR = newID
        WHERE FIRSTNAME = fname AND LASTNAME = lname;
    END IF;
END;

这种方法有效，但同样不会输出错误的ID信息：

SET SERVEROUTPUT ON SIZE 100000
DECLARE
    newID DD_DONOR.IDDONOR%TYPE;
    fname DD_DONOR.FIRSTNAME%TYPE;
    lname DD_DONOR.LASTNAME%TYPE;     
    CURSOR id IS    
    SELECT IDDONOR FROM DD_DONOR
    WHERE FIRSTNAME = fname AND LASTNAME = lname;       
BEGIN
    newID := 305;
    fname := 'Thomas';
    lname := 'Sheer';    
    OPEN id;
    IF SQL%NOTFOUND THEN
        UPDATE DD_DONOR
        SET IDDONOR = newID
        WHERE FIRSTNAME = fname AND LASTNAME = lname;
        DBMS_OUTPUT.PUT_LINE(fname || ' ' || lname || ' ' || 'New ID: ' || newID);
    ELSIF SQL%FOUND THEN
        DBMS_OUTPUT.PUT_LINE('This ID is already assigned.');
    END IF;
    CLOSE id;
END;

这是行不通的，但是我喜欢。看起来应该可以。

SET SERVEROUTPUT ON SIZE 100000
DECLARE
    newID DD_DONOR.IDDONOR%TYPE;
    fname DD_DONOR.FIRSTNAME%TYPE;
    lname DD_DONOR.LASTNAME%TYPE;    
    CURSOR id IS    
    SELECT IDDONOR FROM DD_DONOR
    WHERE FIRSTNAME = fname AND LASTNAME = lname;    
    all_IDs DD_DONOR%rowtype;    
BEGIN
    newID := 305;
    fname := 'Thomas';
    lname := 'Sheer';    
    OPEN id;    
    LOOP
        FETCH id into all_IDs;
        UPDATE DD_DONOR
        SET IDDONOR = newID
        WHERE FIRSTNAME = fname AND LASTNAME = lname;
        DBMS_OUTPUT.PUT_LINE(fname || ' ' || lname || ' ' || 'New ID: ' || newID);          
        EXIT WHEN id%FOUND;
        DBMS_OUTPUT.PUT_LINE('This ID is already assigned.');
    END LOOP; 
    CLOSE id;
END;

Error report -
ORA-06550: line 15, column 9:
PLS-00394: wrong number of values in the INTO list of a FETCH statement
ORA-06550: line 15, column 9:
PL/SQL: SQL Statement ignored
06550. 00000 -  "line %s, column %s:\n%s"
*Cause:    Usually a PL/SQL compilation error.

Answer 1

您的id是NUMBER。您的all_ids是CLOB，基本上是一个很大的字符串字段。查询中的IN子句适用于离散值的显式列表。这不是字符串搜索之类的东西。您可能想要的是一个收藏夹。

IN的工作方式如下：

WHERE id IN (1, 2, 3)

列表的长度必须固定。它也可以像这样工作：

WHERE id IN ( SELECT id FROM table2 )

我不太清楚你要做什么。您的第二个查询会将表中的每行更新为newID，这几乎肯定不是您想要的。如果表中不存在fname和lname，如何识别要更新的行？

Answer 2

请尝试这段代码：

DECLARE
    newID DD_DONOR.IDDONOR%TYPE;
    oldID DD_DONOR.IDDONOR%TYPE;
    fname DD_DONOR.FIRSTNAME%TYPE;
    lname DD_DONOR.LASTNAME%TYPE;    
BEGIN
    newID := 305;
    fname := 'Thomas';
    lname := 'Sheer';    
    select
        iddonor
    into
        oldId
    from
        dd_donor
    WHERE iddonor = newId;
    dbms_output.put_line('This ID is already assigned');
exception
    when NO_DATA_FOUND then
        UPDATE DD_DONOR
        SET IDDONOR = newID
        WHERE FIRSTNAME = fname AND LASTNAME = lname;
        DBMS_OUTPUT.PUT_LINE(fname || ' ' || lname || ' ' || 'New ID: ' || newID); 
END;
/

如果您要坚持使用光标的方法，请在此处更改初始脚本：

已在更改：

all_ids DD_DONOR.IDDONOR％TYPE-不需要CLOB，因为您期望只有一个具有此ID的记录。

游标的声明和调用-添加了参数，因此您可以搜索特定的ID

DECLARE
    all_ids DD_DONOR.IDDONOR%TYPE;
    newID DD_DONOR.IDDONOR%TYPE;
    fname DD_DONOR.FIRSTNAME%TYPE;
    lname DD_DONOR.LASTNAME%TYPE;    
    CURSOR id(newID in DD_DONOR.IDDONOR%TYPE) IS
    SELECT IDDONOR FROM DD_DONOR where iddonor = newID;   
BEGIN
    newID := 305;
    fname := 'Thomas';
    lname := 'Sheer';
    
    OPEN id(newId);
    FETCH id  INTO all_ids;

    IF id%NOTFOUND THEN
        UPDATE DD_DONOR
        SET IDDONOR = newID
        WHERE FIRSTNAME = fname AND LASTNAME = lname;
            DBMS_OUTPUT.PUT_LINE(fname || ' ' || lname || ' ' || 'New ID: ' || newID);
    ELSIF id%FOUND THEN
            DBMS_OUTPUT.PUT_LINE('This ID is already assigned.');
    END IF;

    CLOSE id;
END;
/

谢谢

如何将列的值提取到CLOB变量中？

2 个答案: