在c＃中按日期从ms访问数据库中选择数据

Question

我想在c＃中使用此查询

从ms访问数据库中选择数据

da = new OleDbDataAdapter(
    "SELECT [Column1],[Column2],[Column3],[Date] from [Total] Where [Date] between #" 
        + dateTimePicker2.Value.ToString() 
        + "# AND #" 
        + dateTimePicker3.Value.ToString() 
        + "#", 
    VCON);

它返回null 请帮帮我。

Answer 1

您必须格式化日期，如：

dateTimePicker2.Value.ToString("yyyy/MM/dd")

你也可以这样做：

da = new OleDbDataAdapter(
        "SELECT [Column1],[Column2],[Column3],[Date] from [Total] Where [Date] between "
            + dateTimePicker2.Value.ToString("#yyyy/MM/dd#")
            + " AND "
            + dateTimePicker3.Value.ToString("#yyyy/MM/dd#") ,
        VCON);

但是，我建议你使用参数来避免SQL注入，如下所示：

string query = "SELECT [Column1],[Column2],[Column3],[Date] from [Total] Where [Date] " +
               "BETWEEN @startDate AND @endDate";
OleDbCommand cmd = new OleDbCommand(query, VCON);
cmd.Parameters.AddWithValue("@startDate ", DbType.DateTime).Value = 
                                            dateTimePicker1.Value.ToString("yyyy/MM/dd");
cmd.Parameters.AddWithValue("@endDate ", DbType.DateTime).Value = 
                                            dateTimePicker2.Value.ToString("yyyy/MM/dd");
da = new OleDbDataAdapter(cmd);