You have used comma (,) instead of using AND. I would suggest you to don’t use concatenated query use parameterized query
Refer this.
string connectionString = ConfigurationManager.ConnectionStrings["Constr"].ConnectionString;
string strQuery = "select Product_type,Product_Name,Price from Product_Details where Product_type = @ProductType AND Product_Name = @ProductName AND Price = @Price ";
using (SqlConnection conn = new SqlConnection(connectionString))
{
using (SqlCommand comm = new SqlCommand(strQuery, conn))
{
using (SqlDataAdapter adp = new SqlDataAdapter(comm))
{
comm.Parameters.AddWithValue("@ProductType", this.ddlProductType.SelectedItem.Value);
comm.Parameters.AddWithValue("@ProductName", this.ddlProductName.SelectedItem.Value);
comm.Parameters.AddWithValue("@Price", this.txtPrice.Text);
DataSet ds = new DataSet();
adp.Fill(ds);
GridView2.DataSource = ds;
GridView2.DataBind();
}
}
}