从多列中找到最低和最高值

Question

我在mysql数据库中有一个表，我必须通过indicator_id从多列中获取最低和最高值，

表数据数据如

Indicator_id    threshold_id    colour  Strat_value End_value
2004                1            Green      2            2
2004                2            Amber      1            1
2004                3            Red        0            0
2004                4            Black      -1           -10

我使用了以下代码但未获得正确的结果

select indicator_id,  
       least(Start_value,End_value) low, 
       greatest(Start_value,End_value) high
from shrewd_db.threshold
group by id_indicator;

任何帮助将不胜感激。 感谢

Answer 1

<强> SQL DEMO

SELECT `Indicator_id`, 
        LEAST(MIN(`Strat_value`), MIN(`End_value`)) as smallest,
        GREATEST(MAX(`Strat_value`), MAX(`End_value`)) as biggest
FROM Table1
GROUP BY `Indicator_id`   

<强>输出