MySql代碼：1241操作數應包含1列

Question

在這里，我在與MySQL錯誤：1241相關的stackoverflow中找到了不同的主題。當我閱讀所有主題時，它們在子查詢方面存在一些常見問題。 但是我的問題不同。

問題： -MySql代碼：1241操作數應包含1列

FROM-我的存儲過程之一，帶有准備好的語句

注意 -我的select語句沒有子查詢，也沒有我的update語句。

屏幕拍攝 - 實際SS

儲存程序代碼

CREATE PROCEDURE CancelRow_EM(IN tbl_name VARCHAR(25), IN rowindex FLOAT, OUT flagresult TINYINT, OUT msgresult VARCHAR(300))

 BEGIN
 START TRANSACTION;
IF tbl_name="emps_tbl" THEN
    SET @PrimaryCol="EMPS_ID";
    SET @RefCol="OBR NO.";

ELSEIF tbl_name="emmooe_tbl" THEN
    SET @PrimaryCol="EMMOOE_ID";
    SET @RefCol="PR NO.";

ELSEIF tbl_name="emco_tbl" THEN
    SET @PrimaryCol="EMCO_ID";
    SET @RefCol="PR NO.";

END IF;

SET @select1=CONCAT("SELECT `LINK_ID`,`",@RefCol,"` INTO @li,@Ref FROM `",tbl_name,"` WHERE ROUND(`EMPS_ID`,3)=",rowindex);
PREPARE stmtselect1 FROM @select1;
EXECUTE stmtselect1;
DEALLOCATE PREPARE stmtselect1; 

If @li IS NOT NULL THEN
    SET flagresult=0;
    SET msgresult="Cancellation of record was stopped. Reason: Earmark record was already utilize.";

ELSE
    SET @update1=CONCAT("UPDATE `",tbl_name,"` SET `CANCEL_STATUS`=1 WHERE ROUND(`",@PrimaryCol,"`,3)=",rowindex," AND `",@RefCol,"`='",@Ref,"'");
    PREPARE stmtupdate1 FROM @update1;
    EXECUTE stmtupdate1;

    SELECT row_count() INTO @RowsAffected1;
    DEALLOCATE PREPARE stmtupdate1;

    IF @RowsAffected1>0 THEN
        SET flagresult=1;
        SET msgresult=("No. of affected rows(s):",@RowsAffected1,", from modification process.");
        COMMIT;
    ELSE
        SET flagresult=0;
        SET msgresult=("There are no affected row(s) from modification process.");
        ROLLBACK;   
    END IF;
END IF;

END

Answer 1

您不能將元組分配給單個變量。

這個：

SET msgresult=("No. of affected rows(s):",@RowsAffected1,", from modification process.");

應該：

SET msgresult=CONCAT("No. of affected rows(s):",@RowsAffected1,", from modification process.");

Answer 2

語法錯誤，從選擇中刪除（）。