C#中写入数据库的代码

string s="男"
 string sqlstring = "database=经纪机构;Trusted_Connection=yes;";
            //建立链接数据库的字符串
            SqlConnection conn = new SqlConnection(sqlstring);
            //建立数据库链接
            conn.Open();
            SqlCommand cm = new SqlCommand();
            cm.Connection = conn;
            cm.CommandText = "insert 客户(证件号,姓名,年龄,性别) values('" + textBox2.Text.Trim() + "','" + textBox1.Text.Trim() +"',"+textBox3.Text.Trim()+",'"+s+ "')";
            SqlDataAdapter da = new SqlDataAdapter();
            da.SelectCommand = cm;
            DataSet ds = new DataSet();
            da.Fill(ds);
            conn.Close();
            MessageBox.Show("交易已完成！");
            this.Close();