选择查询到表的最后一行在mysql中给出错误的结果

Question

I want to fetch last row of the table. For this i have used to below query but it returns me 99 where my table contains approx 123 and last pro_id = 123. Right result should be 123.

please suggest me for right way :

 SELECT * FROM product ORDER BY pro_id DESC LIMIT 1

Answer 1

I think the problem is that your pro_id is character and it will be ordered by alphabetical order. You could try to convert it to number first.

SELECT * FROM product ORDER BY CAST(pro_id AS UNSIGNED) DESC LIMIT 1

Answer 2

That's most likely because your pro_id column is defined as text. You can tell sql to order by the numeric value in that column with

SELECT * FROM product ORDER BY CONVERT(pro_id, UNSIGNED INTEGER) DESC LIMIT 1

Answer 3

This query will display a true desc result:

select pro_id from
(SELECT cast(replace(pro_id,' ','') as UNSIGNED) as pro_id from product) as a
ORDER BY pro_id desc limit 1