SQL瘋了！不接受參數，？

Question

alt text http://img24.imageshack.us/img24/3365/sqlnuts.jpg

以及繼承人的代碼

public void select_table_names() 
     {//start
 

     /* display all tables*/ 


     string commandString = null; 
     SqlConnection conn = null; 
     SqlCommand command = null; 
     SqlDataReader reader = null; 


     ArrayList list = new ArrayList(); 



     try 
     { 


      // commandString = "SELECT TABLE_SCHEMA FROM INFORMATION_SCHEMA.TABLES ";// @table "; 


      //string columns; 
      //string tables; 

      //columns = "TABLE_SCHEMA"; 
      //tables = "INFORMATION_SCHEMA.TABLES"; 

      commandString = "SELECT @pthis FROM @tables"; 

      //note when the @tables is replaced by info..schema, still the result is like in figure two" 

      //commandString = "SELECT "+columns+" FROM "+tables;     

      conn = new SqlConnection(Class1.connection); 

      command = new SqlCommand(commandString, conn); 



      // Add the parameters for the SelectCommand. 

      SqlParameter table = new SqlParameter(); 
      command.Parameters.Add("@pthis", SqlDbType.NVarChar, 100); 
      command.Parameters.Add("@tables", SqlDbType.NVarChar, 100); 

      //Add values to these parameters 

      command.Parameters["@tables"].Value = "INFORMATION_SCHEMA.TABLES"; 
      command.Parameters["@pthis"].Value = "TABLE_SCHEMA"; 

      conn.Open(); 

      reader = command.ExecuteReader(); 

      GridView1.DataSource = reader; 
      GridView1.DataBind(); 

      // DropDownList1.DataSource = reader; 
      // DropDownList1.DataTextField = "TABLE_NAME"; 
      // DropDownList1.DataValueField = "TABLE_NAME"; 
      // DropDownList1.DataBind(); 

      reader.Close(); 
      reader.Dispose(); 

      conn.Close(); 
      conn.Dispose(); 

     }//try ends here. 


     catch (SqlException ex) 
     { 



      try 
      { 
       reader.Close(); 
       reader.Dispose(); 

       conn.Close(); 
       conn.Dispose(); 
      } 

      catch (Exception az) 
      { 
       Response.Write(az.Message); 

      } 


      Class1 object1 = new Class1(); 
      object1.errorMessages = new System.Text.StringBuilder(); 
      for (int i = 0; i < ex.Errors.Count; i++) 
      { 
       object1.errorMessages.Append("\n135 \n" + "Index #" + i + "\n" + 
        "Message: " + ex.Errors[i].Message + "\n" + 
        "LineNumber: " + ex.Errors[i].LineNumber + "\n" + 
        "Source: " + ex.Errors[i].Source + "\n" + 
        "Procedure: " + ex.Errors[i].Procedure + "\n"); 
      } 
      Response.Write(object1.errorMessages.ToString()); 

     }//sql catch ends here 




     catch (Exception all) 
     { 


      Label1.Text = "153 all\n" + all.ToString(); 


      try 
      { 
       reader.Close(); 
       reader.Dispose(); 

       conn.Close(); 
       conn.Dispose(); 
      } 

      catch (Exception zx) 
      { 
       Label5.Text = "connection 192 " + zx.Message; 

      } 
      Response.Write(all.Message.ToString()); 










     }//catch all ends 


    }//select_table_names 

Answer 1

SQL Server肯定不允許使用變量作爲表名。至於你的列名變量，它將返回表中結果的數量，但它會輸出TABLE_SCHEMA。

Answer 2

我不熟悉MS-SQL，但是我不認爲參數標記這樣

SELECT @pthis FROM @tables 

工作。

參數通常用來代替文字值，而不是標識符。