在mysql中,我有一个这样的表:这有点复杂,因为mysql不支持排名窗口函数,甚至不支持ctes,所以我尝试使用while循环来实现它
如果导入的和节之间存在任何关系,则应将它们分组在一起。根据关系,它们应分为1、2、3、4、,。。。。
但在这个场景中,我的rn总是1,不知道为什么它不会递增。你能帮我复习一下这个问题吗?我不知道该怎么办。
创建脚本示例:
create table temp1 (
id int, imported int, section int, rn int, checked int default 0
);
insert into temp1(id, section, rn) values (204, 718, 0);
insert into temp1(id, imported, section, rn) values (997,718,034,0);
insert into temp1(id, imported, section, rn) values (998,034,055,0);
insert into temp1(id, imported, section, rn) values (111,453,234,0);
insert into temp1(id, section, rn) values (908, 453,0);
insert into temp1(id, imported, section, rn) values (231,234,890,0);
insert into temp1(id, section, rn) values (342, 567,0);
我的最终结果应该是:
我也尝试过while循环创建存储过程:
DROP PROCEDURE IF EXISTS sp_recursiveimport;
Delimiter $$
CREATE PROCEDURE sp_recursiveimport() -- (IN rnX integer)
BEGIN
DECLARE n INT DEFAULT 0; DECLARE i,j,k INT DEFAULT 0; SELECT COUNT(*) FROM temp1 INTO n;
SET i=0; set @rn = 1; -- set @k = 0;
WHILE i<n DO
set j = 0; select i;
set @sec = (select ifnull(section,0) FROM temp1 LIMIT i,1);
set @imp = (select ifnull(imported,0) FROM temp1 LIMIT i,1); select @imp, @sec;
update1: while j<n do select j;
-- if j=0 then
if (select ifnull(imported,0) from temp1 limit j,1) = @sec and (select checked from temp1 limit j,1) = 0 then
set @update = concat('update temp1 set rn = 1, checked = 1 where imported = ',@sec); select @update; PREPARE stmt_name FROM @update; EXECUTE Stmt_name; DEALLOCATE prepare stmt_name;
set @update1 = concat('update temp1 set rn = 1, checked = 1 where section = ',@sec); select @update1; PREPARE stmt_name FROM @update1; EXECUTE Stmt_name; DEALLOCATE prepare stmt_name;
set k = j;
end if;
if (select ifnull(section,0) from temp1 limit j,1) = @imp and (select checked from temp1 limit j,1) = 0 then
set @update3 = concat('update temp1 set rn = 1, checked = 1 where section = ',@imp); select @update3; PREPARE stmt_name FROM @update3; EXECUTE Stmt_name; DEALLOCATE prepare stmt_name;
set @update4 = concat('update temp1 set rn = 1, checked = 1 where imported = ',@imp); select @update4; PREPARE stmt_name FROM @update4; EXECUTE Stmt_name; DEALLOCATE prepare stmt_name;
set k = j;
end if;
-- set @sec = (select ifnull(imported,0) from temp1 limit k,1);
-- set @imp = (select ifnull(section,0) from temp1 limit k,1); select @sec, @imp;
set j= j+1;
end while update1;
set i = i + 1;
END WHILE;
END;
$$
delimiter;
不知道为什么不行。
暂无答案!
目前还没有任何答案,快来回答吧!