.Net Core如何对MongoDB执行多条件查询

以前项目基本上全部使用MySQL数据库, 最近项目排期空出了一点时间leader决定把日志模块迁移到插入/查询性能更好的MongoDB上. 多条件查询的写法着实费了些功夫, 撰文记录一下.

一、准备工作

1. 安装过程, 不赘述了

2. 添加ReferencePackage

dotnet add package mongodb.bson
dotnet add package mongodb.driver

3. appsetting.json添加连接配置

"MongodbHost": {
  "Connection": "mongodb://[username]:[password]@[ip]:[port]",
  "DataBase": "[database]",
  "Table": ""
 },

4. 获取MongoDBConfig 的方法

public static MongodbHostOptions MongodbConfig()
{
  var builder = new ConfigurationBuilder()
        .SetBasePath(Directory.GetCurrentDirectory())
        .AddJsonFile("appsettings.json");

　　IConfiguration Configuration = builder.Build();
　　var option = Configuration.GetSection("MongodbHost");
　　return new MongodbHostOptions { Connection = option["Connection"], DataBase = option["DataBase"], Table = option["Table"] };
}

二、查询方法

这里的查询方法是网上找的, 直接拿来用了. 如果是单一数据源的话, 这里的host可以提取出来成为helper类的属性.

#region FindListByPage 分页查询集合
  /// <summary>
  /// 分页查询集合
  /// </summary>
  /// <param name="filter">查询条件</param>
  /// <param name="pageIndex">当前页</param>
  /// <param name="pageSize">页容量</param>
  /// <param name="count">总条数</param>
  /// <param name="field">要查询的字段,不写时查询全部</param>
  /// <param name="sort">要排序的字段</param>
  /// <returns></returns>
  public static List<T> FindListByPage(FilterDefinition<T> filter, int pageIndex, int pageSize, out int count, string[] field = null, SortDefinition<T> sort = null)
  {
    try
    {
      MongodbHostOptions host = Tools.AppSettingsTools.MongodbConfig();
      host.Table = "WSMessageLog";
      var client = MongodbClient<T>.MongodbInfoClient(host);
      count = Convert.ToInt32(client.CountDocuments(filter));
      //不指定查询字段
      if (field == null || field.Length == 0)
      {
        if (sort == null) return client.Find(filter).Skip((pageIndex - 1) * pageSize).Limit(pageSize).ToList();
        //进行排序
        return client.Find(filter).Sort(sort).Skip((pageIndex - 1) * pageSize).Limit(pageSize).ToList();
      }

      //指定查询字段
      var fieldList = new List<ProjectionDefinition<T>>();
      for (int i = 0; i < field.Length; i++)
      {
        fieldList.Add(Builders<T>.Projection.Include(field[i].ToString()));
      }
      var projection = Builders<T>.Projection.Combine(fieldList);
      fieldList?.Clear();

      //不排序
      if (sort == null) return client.Find(filter).Project<T>(projection).Skip((pageIndex - 1) * pageSize).Limit(pageSize).ToList();

      //排序查询
      return client.Find(filter).Sort(sort).Project<T>(projection).Skip((pageIndex - 1) * pageSize).Limit(pageSize).ToList();

    }
    catch (Exception ex)
　　{
　　　　throw ex;
　　}
}
#endregion

三、调用查询方法

这里还踩了一个坑. MongoDB里存储的时间是格林尼治时间, 插入8:00, 查询时会发现变成了0:00,所以定义时间属性的时候需要加个标签

[BsonDateTimeOptions(Kind = DateTimeKind.Local)]
public DateTime logtime { get; set; }

这里的OprLogModel是定义了查询条件的类.

public static LogPager<log_operate> Get_operate_log_mongo(OprLogModel qModel)
{
　　LogPager<log_operate> pager = new LogPager<log_operate>();
　　FilterDefinition<log_operate> filters;

　　 var sortbuilder = Builders<log_operate>.Sort;
　　var sort = sortbuilder.Descending("operate_time");

　　#region 用户权限过滤
　　IEnumerable<string> IdList = dev_deviceRepository.GetBinding(qModel.user_id);
　　 filters = Builders<log_operate>.Filter.In("device_id", IdList);
　　#endregion

　　if (!string.IsNullOrEmpty(qModel.device_id))
  {
  　　var filters_did = Builders<log_operate>.Filter.Eq("device_id", qModel.device_id);
  　　filters = Builders<log_operate>.Filter.And(filters, filters_did);
　　}
　　if (qModel.sDate != null)
　　{
　　　　var filters_sdate = Builders<log_operate>.Filter.Gte<DateTime>("operate_time", Convert.ToDateTime(qModel.sDate));
　　　　filters = Builders<log_operate>.Filter.And(filters, filters_sdate);
　　}
　　if (qModel.eDate != null)
　　{
　　　　var filters_edate = Builders<log_operate>.Filter.Lte<DateTime>("operate_time", Convert.ToDateTime(qModel.eDate));
　　　　filters = Builders<log_operate>.Filter.And(filters, filters_edate);
　　}
　　int total;
　　pager.data = MongoTools<log_operate>.FindListByPage(filters, qModel.pageindex, (qModel.pageindex - 1) * qModel.pagesize, out total, null, sort);
　　pager.total = total;
　　return pager;
}
#endregion

也可以先定义一个空的filterdefinition, 然后与各查询条件通过And聚合:

FilterDefinition<log_operate> filters = FilterDefinition<log_operate>.Empty;
var filters_idlist = Builders<log_operate>.Filter.In("device_id", IdList);
filters = Builders<log_operate>.Filter.And(filters, filters_idlist);