Question

我正在尝试过滤搜索绑定到SQL数据连接的GridView控件中的数据，但我没有取得任何成功。每当我尝试搜索某些内容时，都会导致找不到任何记录。这是我的主要搜索代码：

    public void FilterGridView(string column, string terms) //SELECT * FROM [Table_1] WHERE [First Name] LIKE '%valuetosearchfor%' is the format to use here
    {
        DataTable filterTable = new DataTable(); //create a datatable to hold the data while we retrieve it
        SqlConnection connection = new SqlConnection("Data Source=TAMUWINPART\\SQLEXPRESS;Initial Catalog=phpMyWorkers;Integrated Security=True"); //connect to SQL
        try
        {
            connection.Open(); //open the connection

            string filterStatement = "SELECT * FROM [Table_1] WHERE @column LIKE '%@terms%'"; //select all from table_1 with the correct column name / terms

            SqlCommand sqlCmd = new SqlCommand(filterStatement, connection); //make a sql command 
            sqlCmd.CommandType = CommandType.Text; //make it an average joe sql text command

            //define the @ sql variables
            sqlCmd.Parameters.AddWithValue("@column", column);
            sqlCmd.Parameters.AddWithValue("@terms",  terms);

            SqlDataAdapter filterAdapter = new SqlDataAdapter(sqlCmd); //make a data adapter to get all the data from the command and put it into the data table

            filterAdapter.Fill(filterTable);  //fill the data table with the data from the SQL connection

            if(filterTable.Rows.Count > 0)  //if records were found relating to the terms
            {
                //if records WERE found
                workersView.DataSource = filterTable; //set the data source to this instead
                workersView.DataBind(); //refresh the data
            }
            else
            {
                //no records were found in this case, do not be an inneficient guy who will refresh the gridview for no reason
                FilterSearchTerms.Text = "0 Records Found!"; //notify the user that he/she won't get anything
            }
        }
        catch (System.Data.SqlClient.SqlException ex) //if the thing just decides that it doesn't want to work today
        {
            string msg = "myWorkers had a problem fetching the data : ";
            msg += ex.Message;
            throw new Exception(msg);
        }
        finally
        {
            connection.Close(); //close the connection
        }
    }

    public void FilterSearchButton_Click(object sender, EventArgs e) //when someone clicks the button to filtersearch the gridviews
    {
        string column = FilterSearchDropdown.SelectedValue.ToString(); //get the column that the user wants to filter by and make sure it's a string
        string terms = FilterSearchTerms.Text;    //get the terms to search by - verified string for sure

        FilterGridView(column, terms);
    }

    public void FilterRemoveButton_Click(object sender, EventArgs e) //when someone decides to remove the filter
    {
        BindGridView(); //refresh the gridview based on all of the data
        FilterSearchTerms.Text = ""; //remove the text from the filter search terms box
    }

这是布局的图片。

即使我搜索真实数据，也会导致其被称为

        else
        {
            //no records were found in this case, do not be an inneficient guy who will refresh the gridview for no reason
            FilterSearchTerms.Text = "0 Records Found!"; //notify the user that he/she won't get anything
        }

表示数据表的行数为0 ...

有谁知道为什么？谢谢。

Answer 1

我怀疑您的SQL LIKE代码不正确。在这个问题中看看如何与SQL参数一起使用：how-to-get-like-clause-to-work-in-ado-net-and-sql-server。它还有助于显示发送到数据库的最终sql命令文本。

Answer 2

替换此行：

 string column = FilterSearchDropdown.SelectedValue.ToString();

用这个：

 string column = FilterSearchDropdown.SelectedText;

此外，您需要更正您的命令字符串和命令参数，如Emmad Kareem在其他答案中所建议的那样。您的字符串和参数应如下所示：

  string filterStatement = "SELECT * FROM [Table_1] WHERE [{0}] LIKE @terms"; //select all from table_1 with the correct column name / terms
  filterStatement = string.Format(filterStatement, column);
  ....      ....      ....      ....      ....      ....  

 // sqlCmd.Parameters.AddWithValue("@column", column );
  sqlCmd.Parameters.AddWithValue("@terms", "%" + terms + "%");

Answer 3

您只需要替换此查询：

string filterStatement = "SELECT * FROM [Table_1] WHERE @column LIKE '%"+terms+"%'";

您应该能够找到您的数据。

搜索过滤GridView控件导致未找到任何记录

3 个答案: