PetaPoco/SQLite 聚合日期错误的解决方法 [英] Workaround for PetaPoco / SQLite aggregate date bug

问题描述

这是创建 SQLite 数据库、将一些数据填充到表中然后尝试检索它的完整代码.如果日期时间列周围有聚合函数，PetaPoco 将抛出错误.

Here's complete code to create a SQLite database, fill some data into a table and then try to retrieve it. If there's an aggregate function around a datetime column, PetaPoco will throw an error.

using System;
using PetaPoco;

class Program
{
    static void Main(string[] args)
    {
        bool filenew = false;
        if (!System.IO.File.Exists(@"c:\temp\database.sq3"))
            filenew = true;
        System.Data.SQLite.SQLiteConnection sqltc = new System.Data.SQLite.SQLiteConnection("Data Source=" + @"c:\temp\database.sq3");
        sqltc.Open();
        PetaPoco.Database db = new Database(sqltc);
        if (filenew)
            db.Execute("create table test1 (ID_CHANNEL integer primary key autoincrement, dtfld DateTime null, name string)");
        test1 t = new test1();
        t.name = "No Date";
        db.Insert(t);
        t = new test1();
        t.dtfld = DateTime.Now;
        t.name = "with date";
        db.Insert(t);
// SUCCESS:
        test1 lt1 = db.First<test1>("select dtfld from test1 where ID_Channel = 2");
// FAILURE:
        test1 lt2 = db.First<test1>("select max(dtfld) as dtfld from test1 where dtfld is not null");
    }

    [PetaPoco.TableName("test1")]
    [PetaPoco.PrimaryKey("ID_Channel")]
    public class test1
    {
        public long ID_Channel { get; set; }
        public DateTime? dtfld { get; set; }
        public string name { get; set; }
    }
}

任何人都可以建议修复仍然意味着 POCO 对象包含日期时间，并且我仍然可以访问日期的最大值?

Can anybody suggest a fix that still means the POCO object contains a datetime, and I can still access the max of a date?

推荐答案

找到解决方案 - 切换到 NPoco.对上面的唯一更改是将PetaPoco"替换为NPoco".

Found a solution - switch to NPoco. The only change to above was to replace "PetaPoco" with "NPoco".

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