BindingSource无法执行＆＃39; Like＆＃39; System.DateTime和System.String上的操作

Question

我想使用搜索框过滤datagridview，我有一个适用于字符串的函数，但我不知道为什么当我使用包含int / date值的列的函数时出现异常：

 public void SearchTable(TextBox searchBox, String columnNameToSearch, int Type)
    {
        BindingSource bs;
        switch (Type)
        {
            case NUMERIC_COLUMN:
                bs = new BindingSource
                {
                    DataSource = _dgv.DataSource,
                    Filter = columnNameToSearch + " = " + searchBox.Text.Trim()
                };
                _dgv.DataSource = bs;
                break;
            case TEXT_COLUMN:
                bs = new BindingSource
                {
                    DataSource = _dgv.DataSource,
                    Filter = columnNameToSearch + " LIKE '" + searchBox.Text.Trim() + "%'"
                };
                _dgv.DataSource = bs;
                break;
        }
    }

这是例外： http://i.stack.imgur.com/IU1Xr.png

当我在SQL服务器中尝试查询时，查询工作