我如何为此构建查询

Question

我有一张这样的表：

staffname | periods
___________________
david     |     yes
seema     |     no
raj       |     yes
seema     |     no
david     |     yes

现在我想要这样的结果：

staffname | periods
___________________
david     |     2
seema     |     2
raj       |     1

如果你能理解我想要的名字和数量，对第二栏的价值无关紧要。

我试过了，但我得到了重复的行。

请帮忙。

Answer 1

试试这个：

SELECT STAFFNAME, COUNT(*) as PERIODS
   FROM TABLE
 GROUP BY STAFFNAME

Answer 2

试试这个

   select staffname, count(periods) as periods from table1 
   group by staffname

如果你想按照你的结果订购它们，只需在最后添加

    order by periods desc

demo here

Answer 3

尝试以下代码。它可以根据需要提供精确的结果。

select staffname, count(1) as 'periods' from table1
group by staffname order by periods desc, staffname;

链接到sqlfiddle。

Answer 4

    SELECT staffname, COUNT(*) AS periods 
    FROM first_table 
    GROUP BY staffname
    ORDER BY periods DESC

Answer 5

很简单，

SELECT staffname,COUNT(periods) AS periods
FROM TableName
Group By staffname