DB2 存儲過程中執行動態SQL的兩種寫法

樣本代碼：

DROP PROCEDURE QUOTATION.COPY_SAMPLE;
CREATE PROCEDURE QUOTATION.COPY_SAMPLE (
    IN tableNameFrom VARCHAR(30)
    , IN tableNameTo VARCHAR(30)
    , INOUT copyResult INTEGER)

BEGIN
    DECLARE SQLCODE INTEGER DEFAULT 0;

    SET copyResult = 0;

    -- Proecss 1
    BEGIN
        DECLARE fromSql VARCHAR(32672);
        DECLARE toSql VARCHAR(32672);
        DECLARE seqTo VARCHAR(30);
        DECLARE templateParserId INTEGER;
        DECLARE uuid VARCHAR(36);
        DECLARE stmt STATEMENT;
        DECLARE curs CURSOR FOR stmt;

        SET seqTo = 'SEQ_' || tableNameTo;

        SET fromSql = 'SELECT MAX(TEMPLATE_PARSER_ID), UUID FROM QUOTATION.' || tableNameFrom || ' GROUP BY UUID';
        PREPARE stmt FROM fromSql;
        OPEN curs;
        CURSORLOOP:
            LOOP
                FETCH curs INTO templateParserId, uuid;
                -- Do nothing if no data or processed all datas.
                IF SQLCODE = 100 THEN LEAVE CURSORLOOP;
                END IF;

                SET uuid = (SELECT CONCAT(HEX(RAND()), HEX(RAND())) FROM SYSIBM.SYSDUMMY1);
                SET toSql = 'INSERT INTO QUOTATION.' || tableNameTo || ' (TEMPLATE_PARSER_ID, UUID) VALUES (NEXTVAL FOR QUOTATION.' || seqTo || ',''' || uuid || ''')';
                PREPARE s FROM toSql;
                EXECUTE s;
            END LOOP;
        CLOSE curs;
    END;

    -- Proecss 2
    BEGIN
        -- ......
    END;

    SET copyResult = 1;
END;

注意點：
1、SQLCODE必須要定義，且必須定義在最外層的BEGIN的下面。
2、必須要判斷SQLCODE是否等於100，等於100時退出CURSORLOOP，否則會死循環。
3、“OPEN curs”之後不要忘記“CURSORLOOP:”。