表说明
- 表名:固定的前缀+%Y%m%d, 如
summary_20220809 - 表结构:count BIGINT, id BIGINT
查询单个表值示例
select count from @table where id = @id;
思路
是否只能用循环日期+动态 sql 处理?
伪代码如下:
create PROCEDURE findMaxDay(id INT, mouth VARCHAR(255);)
begin
-- 省略一些赋值
WHILE x <= 31 DO
set table_name = CONCAT('summary_',mouth, lpad(x,2,0));
-- 查询单表结果并赋值
set sql = CONCAT("select count INTO @tmp from '", table_name, "' where id = '", id,"'");
PREPARE stmt FROM @sql;
EXECUTE stmt;
deallocate prepare stmt;
-- 比较和更新结果
set @day = IF( @tmp > @max, lpad(x,2,0), @day);
set @max = max(tmp, max);
set x = x + 1;
END WHILE;
-- 输出结果
select day;
end
请大佬看看这样的思路对不对?有没有更好的方案。