Mysqlプロシージャ：条件ブロック内のbegin文のネスト

Question

変数が存在する場合にのみコードブロックを実行しようとしています。ここにコードスニッピットがあります。 IFブロック内の文を終了できますか？

私はこれを何度か再設計しました。提案？

delimiter // 


drop trigger if exists example_trigger;// 
create trigger example_trigger AFTER UPDATE on some_table for each row 
BLOCK1: begin 

    -- check current status 
    DECLARE done BOOLEAN DEFAULT FALSE; 


    -- cap check 
    if (new.CURRENT_ALLOCATED >= new.TOTAL_ALLOWED_QTY) then 
     SET done = TRUE; 
    end if; -- cap check end 


    -- o 
    if (done != TRUE and new.O_KEY is not null and new.A_KEY is null) then 

     OBLOCK: begin 
      DECLARE done_o BOOLEAN DEFAULT FALSE; 
      DECLARE pd_nbr INT; 
      DECLARE no_more_rows BOOLEAN; 
      DECLARE cur_pd CURSOR FOR 
       select pd.STATUS_KEY 
       from PROD_DEL_V pd 
        join PROD_T p on pd.KEY_NBR = p.KEY_NBR 
       where pd.STATUS not in ('PU', 'EX') 
        and p.O_KEY = new.O_KEY; 
      DECLARE CONTINUE HANDLER FOR NOT FOUND 
       SET done_o = TRUE; 

      -- run updates 
      if (done_o != TRUE) then 

       -- open cursor 
       OPEN cur_pd;   

       -- loop start 
       loop_it: LOOP 

        FETCH cur_pd INTO pd_nbr; 

        -- exit loop if.. 
        if no_more_rows = TRUE THEN 
         CLOSE cur_pd; 
         LEAVE loop_it; 
        end if; 


        INSERT INTO STATUS_TABLE (
         STATUS_KEY 
         , STATUS 
         , NOTE_TXT 
         ) 
         (
         SELECT 
          PD.STATUS_KEY 
          , 'PU' AS STATUS 
          , concat('example_trigger - MAX has been reached or exceeded [TOTAL_ALLOWED_QTY = ',new.TOTAL_ALLOWED_QTY,' and CURRENT_ALLOCATED = ', new.CURRENT_ALLOCATED, ']') AS NOTE_TXT 
         FROM PROD_DEL_TABLE PD 
         WHERE PD.STATUS_KEY = pd_nbr 
         ); 

       END LOOP loop_it; 

      end if; -- run updates end 

     end OBLOCK:; -- end block 

    end if; -- o 


    -- a 
    if (done != TRUE and new.O_KEY is null and new.A_KEY is not null) then 

     ABLOCK: begin 
      DECLARE done_a BOOLEAN DEFAULT FALSE; 
      DECLARE pd_nbr INT; 
      DECLARE no_more_rows BOOLEAN; 
      DECLARE cur_pd CURSOR FOR 
       select pd.STATUS_KEY 
       from PROD_DEL_V pd 
        join PROD_T p on pd.KEY_NBR = p.KEY_NBR 
        join A_O_T a on a.O_KEY = p.O_KEY 
       where pd.STATUS not in ('PU', 'EX') 
        and a.A_KEY = new.A_KEY; 
      DECLARE CONTINUE HANDLER FOR NOT FOUND 
       SET done_a = TRUE; 

      -- run updates 
      if (done_a != TRUE) then 

       -- open cursor 
       OPEN cur_pd;   

       -- loop start 
       loop_it: LOOP 

        FETCH cur_pd INTO pd_nbr; 

        -- exit loop if.. 
        if no_more_rows = TRUE THEN 
         CLOSE cur_pd; 
         LEAVE loop_it; 
        end if; 


        INSERT INTO STATUS_TABLE (
         STATUS_KEY 
         , STATUS 
         , NOTE_TXT 
         ) 
         (
         SELECT 
          PD.STATUS_KEY 
          , 'PU' AS STATUS 
          , concat('example_trigger - MAX has been reached or exceeded [TOTAL_ALLOWED_QTY = ',new.TOTAL_ALLOWED_QTY,' and CURRENT_ALLOCATED = ', new.CURRENT_ALLOCATED, ']' AS NOTE_TXT 
         FROM PROD_DEL_TABLE PD 
         WHERE PD.STATUS_KEY = pd_nbr 
         ); 

       END LOOP loop_it; 

      end if; -- run updates end 

     end ABLOCK; -- end block 

    end if; -- a 
end BLOCK1; -- end large block 
// 

delimiter ; 

Answer 1

IFとBEGIN ... END句の問題点は何ですか？この単純な例を見てみましょう -

CREATE PROCEDURE procedure1(IN Param1 VARCHAR(255)) 
BEGIN 
    IF Param1 = 1 THEN 
    BEGIN 
     DECLARE i INT; 
     -- do something 
    END; 
    ELSE 
    BEGIN 
     DECLARE i INT; 
     -- do something 
    END; 
    END IF; 
END