如何在SQLite中按月和年选择

Question

在我的SQlite表中，它有DateTime字段示例：order_date

如何执行这些任务：

1. 按月份检索记录，如2013年1月，2月，3月等。
2. 使用上述条件（1）
按开始日期和结束日期检索记录

由于

How to convert `DateTime` for format requires by SQLite for (1) and (2) 

    DateTime  Dt = new DateTime.Today();
    Month-year ?  Year?


    Records = await db.QueryAsync("Select * From Purchase where order_date=" + "Month-Year");

In SQLite , which operator is correct : `=` or `==`? 

----- Update:

using SQlite:strftime

SELECT * FROM tablename WHERE strftime('%Y', Order_Date) = '2013' AND strftime('%m', Order_Date) = '2';

1) Is there a function to get month as number from DateTime?

Answer 1

我假设您使用的是sqlite-net。

因此，您可以在查询中使用参数：

//Returning all records from February 2013
Records = await db.QueryAsync<Purchase>("Select * From Purchase where order_date >= ? and order_date < ?", new DateTime(2013, 2, 1), new DateTime(2013, 3, 1));