'select into'語句在帶有游標的mysql存儲過程中不起作用

Question

這是問題所在：temprequest是我從中獲取行的表。 我在獲取時根據temprequest表查找可交付表的deliveryableId列。 因此，我使用select into語句。 但我將查找值放在其中的變量僅適用於獲取的第一行。

“開始結尾”塊：

DECLARE no_more_rows BOOLEAN;
DECLARE nr_rows INT DEFAULT 0;  
DECLARE loop_cntr INT DEFAULT 0;

declare delId int;

declare vtname varchar(200);
declare tversion varchar(200);
declare custId int;
declare prod varchar(200);

DECLARE c_temp CURSOR FOR select tname, version,BuID,BuprodName from temprequest;
SET no_more_rows = False;

OPEN c_temp;
select FOUND_ROWS() into nr_rows;

the_loop:LOOP
    FETCH c_temp into vtname,tversion,custId, prod;
    IF no_more_rows THEN            
        LEAVE the_loop;
    END IF;
    -- statements for each request record
    Set delId= (SELECT deliverableId  
                FROM deliverable 
                WHERE deliverable.Product_prodName =vtname AND deliverable.version = tversion);
    INSERT INTO request VALUES (delId, custId, prod);               
    SET loop_cntr = loop_cntr + 1;

END LOOP the_loop;
CLOSE c_temp;

Answer 1

要在沒有光標的情況下完成相同的操作，請使用（UPDATED ）：

INSERT INTO request 
SELECT 
    deliverable.deliverableId   as delId,
    qwe.BuID            as custId,
    qwe.BuprodName          as prod

FROM deliverable 
inner join 
(select tname, version, BuID,BuprodName 
from temprequest) 
    as qwe (tname, version, BuID,BuprodName) 
        on deliverable.Product_prodName = qwe.vtname 
       AND deliverable.version = qwe.tversion

我剛剛意識到BuID和BuprodName在這里是常量，除了insert語句之外沒有在其他地方使用。

Answer 2

如果游標內的任何查詢均未獲取任何結果，則將no_more_rows變量設置為true。 在您的情況下，如果以下查詢未獲取任何結果，即使在這種情況下， no_more_rows也將被評估為true 。

SELECT deliverableId  
FROM deliverable 
WHERE deliverable.Product_prodName =vtname AND deliverable.version = tversion

解決方案是在游標的末尾將no_more_rows設置為false，以便即使在游標執行期間將其評估為true，也將重置該游標並僅在游標查詢沒有返回任何行時退出。

he_loop:LOOP
    FETCH c_temp into vtname,tversion,custId, prod;
    IF no_more_rows THEN            
        LEAVE the_loop;
    END IF;
    -- statements for each request record
    Set delId= (SELECT deliverableId  
                FROM deliverable 
                WHERE deliverable.Product_prodName =vtname AND deliverable.version = tversion);
    INSERT INTO request VALUES (delId, custId, prod);               
    SET loop_cntr = loop_cntr + 1;
    SET no_more_row = false
END LOOP the_loop;