请问这段代码错在哪里？

Question

string worksitename = this.Request.QueryString["worksitename"].ToString();
        this.Label1.Text = worksitename;        string sql = "select Count(worksitename) from jy_workcircs_tb where worksitename=" + worksitename;
        SqlConnection conn = new SqlConnection(ConnString);
        SqlCommand cmd = new SqlCommand(sql, conn);
        conn.Open();
        int count = int.Parse(cmd.ExecuteScalar().ToString());
        this.Label2.Text = count.ToString();

Answer 1

try
 
string worksitename = this.Request.QueryString["worksitename"].ToString();
        this.Label1.Text = worksitename;        string sql = "select Count(worksitename) from jy_workcircs_tb where worksitename='" + worksitename+"'"; //字符串前後加上單引號'
        SqlConnection conn = new SqlConnection(ConnString);
        SqlCommand cmd = new SqlCommand(sql, conn);
        conn.Open();
        int count = int.Parse(cmd.ExecuteScalar().ToString());
        this.Label2.Text = count.ToString();

Answer 2

int count = int.Parse(cmd.ExecuteScalar().ToString());
==>
Int32 count = (int32) cmd.ExecuteScalar();

Answer 3

跟踪调试得到sql，在查询分析器能不能查询