选择只有一行匹配不同的值

Question

我想知道如何查询此结构： 我怎样才能

SELECT only 1 ID FROM portfolio 
WHERE category = "x" AND DISTINCT description = 'x'? 

（表名和字段）

portfolio: 
ID, client, section, category, description, year, files 

编辑：谢谢您答案。

Answer 1

SELECT ID from portfolio WHERE category = 'x' AND description = 'x' LIMIT 1; 

Answer 2

SELECT MAX(ID) 
FROM profolio 
WHERE category = 'x' AND description = 'x' 

Answer 3

你可以像下面那样在mysql中使用limit语句。

select id from portfolio where category='x' and description='x' limit 1 offset 0