mysql - mysql 将多行插入单行

Question

以下脚本旨在具有以下功能:

1. 在 eurusd_m1 中查找 Volume=250 的行，
2. 查找第 1 行之前的行，
3. 找到第 1 行之后的行，

4. 将每一行中所需的值复制到 obsh4 中的一行中

   Create procedure doji_result ()
   begin 
   
   DECLARE initial DATETIME;
   DECLARE final DATETIME;
   DECLARE centre DATETIME;
   DECLARE x int;
   
   SET x = 0;
   
   SET @initial = (select MQLTime from eurusd_m1 where volume=250 
   order by mqltime asc limit 1);
   
   SET @final = (select MQLTime from eurusd_m1 where volume=250 
   order by mqltime desc limit 1);
   
   REPEAT
   
   SET @centre = (select MQLTime from eurusd_m1 where volume=250 
   order by mqltime asc limit x,1);
   
   INSERT INTO obsh4 (MQLrefTime,RrefTime,Open,High,Low,Close,Volume) 
   select MQLTime,RTime,Open,high,Low,Close,Volume 
   from eurusd_m1 where MQLTime = @centre 
   order by MQLTime asc limit 1; 
   
   INSERT INTO obsh4 (Open2,High2,Low2,Close2,Volume2) 
   select Open,high,Low,Close,Volume 
   from eurusd_m1 where MQLTime < @centre 
   order by MQLTime desc limit 1; 
   
   INSERT INTO obsh4 (Open3,High3,Low3,Close3,Volume3) 
   select Open,high,Low,Close,Volume 
   from eurusd_m1 where MQLTime > @centre 
   order by MQLTime asc limit 1; 
   
   SET x=x+1;
   
   UNTIL @centre=@final
   END REPEAT;
   
   END $$
   DELIMITER ;
   

   当我运行此命令时，eurusd_m1 中的每一行都会复制到 obsh4 中的新行(而不是在每次循环迭代时将所有三行折叠成一行)

   我尝试使用以下脚本使用 UPDATE 添加第二行和第三行数据，但是我在 FROM 上遇到语法问题，我不知道如何解决这个问题:/

   update obsh4
   set  Open2 = open,
        High2 = high,
        Low2 = low,
        Close2 = close,
        Volume2 = volume, 
   from select Open,high,Low,Close,Volume from eurusd_m1
   where
   MQLTime < @centre order by MQLTime desc limit 1; 
   

我可以看到三个选项:

1)更新语句需要修正

2)需要在第二/第三行的插入中添加行规范

3)从头开始分箱并生成一些东西。

我们非常欢迎对其中任何一个提出任何建议。 谢谢

编辑:循环本身运行正常，并且已经独立于当前问题进行了测试。

Answer 1

用这段冗长的代码回答了问题。我认为我可以稍微简化一下，所以我很乐意接受建议。

drop procedure if exists doji_result; 
DELIMITER $$
Create procedure doji_result ()
begin 

DECLARE final DATETIME;
DECLARE centre DATETIME;
DECLARE openB1 DOUBLE;
DECLARE highB1 DOUBLE;
DECLARE lowB1 DOUBLE;
DECLARE closeB1 DOUBLE;
DECLARE volumeB1 DOUBLE;
DECLARE openA1 DOUBLE;
DECLARE highA1 DOUBLE;
DECLARE lowA1 DOUBLE;
DECLARE closeA1 DOUBLE;
DECLARE volumeA1 DOUBLE;

DECLARE x int;

SET x = 0;

SET @final = (select MQLTime from eurusd_m1 where volume=250 
order by mqltime desc limit 1);

REPEAT

SET @centre = (select MQLTime from eurusd_m1 where volume=250 
order by mqltime asc limit x,1);

SET @openB1 = (select open from eurusd_m1 where MQLtime < @centre order by mqltime desc limit 1);
SET @highB1 = (select high from eurusd_m1 where MQLtime < @centre order by mqltime desc limit 1);
SET @lowB1 = (select low from eurusd_m1 where MQLtime < @centre order by mqltime desc limit 1);
SET @closeB1 = (select close from eurusd_m1 where MQLtime < @centre order by mqltime desc limit 1);
SET @volumeB1 = (select volume from eurusd_m1 where MQLtime < @centre order by mqltime desc limit 1);

SET @openA1 = (select open from eurusd_m1 where MQLtime > @centre order by mqltime asc limit 1);
SET @highA1 = (select high from eurusd_m1 where MQLtime > @centre order by mqltime asc limit 1);
SET @lowA1 = (select low from eurusd_m1 where MQLtime > @centre order by mqltime asc limit 1);
SET @closeA1 = (select close from eurusd_m1 where MQLtime > @centre order by mqltime asc limit 1);
SET @volumeA1 = (select volume from eurusd_m1 where MQLtime > @centre order by mqltime asc limit 1);

INSERT INTO obsh4 (MQLrefTime,RrefTime,Open,High,Low,Close,Volume) 
select MQLTime,RTime,Open,high,Low,Close,Volume 
from eurusd_m1 where MQLTime = @centre 
order by MQLTime asc limit 1; 

update obsh4
SET open2 = @openB1,
    high2 = @highB1,
    low2 = @lowB1,
    close2 = @closeB1,
    volume2 = @volumeB1,
    open3 = @openA1,
    high3 = @highA1,
    low3 = @lowA1,
    close3 = @closeA1,
    volume3 = @volumeA1
order by mqlreftime desc limit 1;

SET x=x+1;

UNTIL @centre=@final
END REPEAT;

END $$
DELIMITER ;