SELECT Max(*) as mymax FROM score where subject='" + comboBox1.Text + "'", mycon 该查询结果写成代码

SELECT Max(*) as mymax FROM score where subject='" + comboBox1.Text + "'", mycon
SELECT Min(*) as mymin FROM score where subject='" + comboBox1.Text + "'", mycon
SELECT Avg(*) as myavg FROM score where subject='" + comboBox1.Text + "'", mycon
SELECT Count(*) as mycount FROM score where subject='" + comboBox1.Text + "' and score>60", mycon
写成代码，求大佬！！！

好的，我来回答你的问题：

如果使用 C#，可以将 SQL 语句写成字符串，再使用 SqlCommand 类执行查询，例如：

string subject = comboBox1.Text;
string sql = "SELECT Max(*) as mymax FROM score where subject=@subject";
SqlCommand command = new SqlCommand(sql, mycon);
command.Parameters.AddWithValue("@subject", subject);
int maxScore = (int) command.ExecuteScalar();

其中，使用 @subject 作为参数名，可以避免 SQL 注入攻击；ExecuteScalar() 方法可以返回查询结果中的第一行和第一列，即最大分数。

同样地，最小分数、平均分数、及格人数也可以用类似的方法查询，代码如下：

// 最小分数
string sql = "SELECT Min(*) as mymin FROM score where subject=@subject";
SqlCommand command = new SqlCommand(sql, mycon);
command.Parameters.AddWithValue("@subject", subject);
int minScore = (int) command.ExecuteScalar();

// 平均分数
string sql = "SELECT Avg(*) as myavg FROM score where subject=@subject";
SqlCommand command = new SqlCommand(sql, mycon);
command.Parameters.AddWithValue("@subject", subject);
double avgScore = (double) command.ExecuteScalar();

// 及格人数
string sql = "SELECT Count(*) as mycount FROM score where subject=@subject and score>60";
SqlCommand command = new SqlCommand(sql, mycon);
command.Parameters.AddWithValue("@subject", subject);
int passCount = (int) command.ExecuteScalar();