Question

我希望我的功能显示“找到空发票！”＃39;或者＆＃39;未找到发票＆＃39;错误消息。但是当我选择有错误的数据时（表中不存在），它返回“没有选择行”＃39;请指导我选择正确的方法。

SET ECHO ON;
SET SERVEROUTPUT ON;

CREATE OR REPLACE FUNCTION totalInvoiceAmount(InvoiceNo IN       INVOICE_ITEM.InvoiceNumber%TYPE)
RETURN NUMBER IS
TotalCost NUMBER(20);

CURSOR X_RECORD IS SELECT * FROM INVOICE_ITEM;
CURSOR Y_RECORD IS SELECT * FROM INVOICE_ITEM;

tempCost NUMBER:=0;
InvoiceCheck BOOLEAN:=FALSE;
InvoiceEmpty BOOLEAN:=TRUE;

BEGIN
FOR Record IN X_RECORD LOOP 
    IF Record.InvoiceNumber = InvoiceNo THEN
        InvoiceCheck:=TRUE;
        EXIT;
    ELSE
        InvoiceCheck:=FALSE;
    END IF;
END LOOP;   

FOR Record IN Y_RECORD LOOP 
    IF Record.InvoiceNumber = InvoiceNo AND InvoiceCheck=FALSE THEN
        InvoiceEmpty:=TRUE;
        EXIT;
    ELSE
        InvoiceEmpty:=FALSE;
    END IF;
END LOOP;

IF InvoiceCheck=FALSE AND InvoiceEmpty=FALSE THEN
    DBMS_OUTPUT.PUT_LINE('Invoice Not Found!');
    RETURN -1;
ELSIF InvoiceCheck=FALSE AND InvoiceEmpty=TRUE THEN
    DBMS_OUTPUT.PUT_LINE('Empty Invoice Found!');
    RETURN 0;
ELSE
    FOR Record IN X_RECORD LOOP 
        IF Record.InvoiceNumber = InvoiceNo THEN
            tempCost:=tempCost+(Record.UnitPrice*Record.Quantity);
        END IF;
    END LOOP;
    TotalCost:=tempCost;
    RETURN TotalCost;
END IF;
END;

/

SELECT invoicenumber,totalInvoiceAmount(invoicenumber) AS "Total Cost" FROM INVOICE_ITEM Where invoicenumber=2011011;

SELECT invoicenumber,totalInvoiceAmount(invoicenumber) AS "Total Cost" FROM INVOICE_ITEM where invoicenumber=2011010;

Answer 1

您想要的消息来自您在SELECT语句中调用的函数。因此，如果SELECT没有返回任何行，则没有可用于调用该函数的行。

我担心你不清楚自己想要达到的目标，但无论如何，你需要一种不同的方法。说过我建议这样的东西可能会给你你想要的东西（以更正统和更有效的方式）：

SELECT invoicenumber, 
       sum(UnitPrice*Quantity) AS "Total Cost" 
FROM INVOICE_ITEM 
where invoicenumber=2011010
group by InvoiceNumber;

Answer 2

SET ECHO ON;
SET SERVEROUTPUT ON;

CREATE OR REPLACE FUNCTION totalInvoiceAmount(InvoiceNo IN       INVOICE_ITEM.InvoiceNumber%TYPE)
RETURN NUMBER IS
TotalCost NUMBER(20);
invoice_not_found EXCEPTION ;
empty_invoice_found EXCEPTION ;


CURSOR X_RECORD IS SELECT * FROM INVOICE_ITEM;
CURSOR Y_RECORD IS SELECT * FROM INVOICE_ITEM;

tempCost NUMBER:=0;
InvoiceCheck BOOLEAN:=FALSE;
InvoiceEmpty BOOLEAN:=TRUE;

BEGIN
FOR Record IN X_RECORD LOOP 
    IF Record.InvoiceNumber = InvoiceNo THEN
        InvoiceCheck:=TRUE;
        EXIT;
    ELSE
        InvoiceCheck:=FALSE;
    END IF;
END LOOP;   

FOR Record IN Y_RECORD LOOP 
    IF Record.InvoiceNumber = InvoiceNo AND InvoiceCheck=FALSE THEN
        InvoiceEmpty:=TRUE;
        EXIT;
    ELSE
        InvoiceEmpty:=FALSE;
    END IF;
END LOOP;

IF InvoiceCheck=FALSE AND InvoiceEmpty=FALSE THEN
    --DBMS_OUTPUT.PUT_LINE('Invoice Not Found!');
    RAISE invoice_not_found;
    --RETURN -1;
ELSIF InvoiceCheck=FALSE AND InvoiceEmpty=TRUE THEN
    --DBMS_OUTPUT.PUT_LINE('Empty Invoice Found!');
    RAISE empty_invoice_found
    RETURN 0;
ELSE
    FOR Record IN X_RECORD LOOP 
        IF Record.InvoiceNumber = InvoiceNo THEN
            tempCost:=tempCost+(Record.UnitPrice*Record.Quantity);
        END IF;
    END LOOP;
    TotalCost:=tempCost;
    RETURN TotalCost;
END IF;
EXCEPTION
when invoice_not_found then
 DBMS_OUTPUT.PUT_LINE('Invoice Not Found!');
 raise -1;
when empty_invoice_found then
 DBMS_OUTPUT.PUT_LINE('Empty Invoice Found!');
 raise 0;

END;

您可以在异常中捕获它并相应地处理它，让我知道它是否有效

显示错误消息，而不是“未选择任何行”＃39;

2 个答案: