如何计算表格中没有的值? [英] how to count no of values in a table?

问题描述

此代码给出了一个异常，指出"incorrect syntax near the word DISTINCT"
此查询有什么问题?

this code gives a exception saying that "incorrect syntax near the word DISTINCT"
what is wrong in this query?

private SqlConnection con;
private SqlCommand cmd;
private SqlDataReader dr;

openConnection();
string qry1 = "SELECT COUNT (V1) FROM votes GROUP BY DISTINCT V1";
cmd = new SqlCommand(qry1, con);

dr = cmd.ExecuteReader();
while (dr.Read())
{
 count = dr[0].ToString();
}
int ans= Convert.ToInt32(count);
MessageBox.Show(Convert.ToString(ans));

closeConnection();

推荐答案

SELECT COUNT (DISTINCT V1) FROM votes group by v1;

尝试一下...

TRY THIS...

更改此项:

change this:

string qry1 = "SELECT COUNT (V1) FROM votes GROUP BY DISTINCT V1";

与此:

with this:

string qry1 = "SELECT COUNT (V1) FROM votes GROUP BY V1";

希望这会有所帮助:)

hope this helps :)

尝试一下

从投票中选择DISTINCT COUNT(V1)，按V1分组

TRY THIS

SELECT DISTINCT COUNT (V1) FROM votes GROUP BY V1

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