Update mongodb

This commit is contained in:
sunkaixuan 2025-05-01 14:09:30 +08:00
parent 25ec702d23
commit e24acf4fce
2 changed files with 37 additions and 12 deletions

View File

@ -3,6 +3,7 @@ using System.Data.Common;
using System.Data;
using MongoDB.Bson;
using MongoDB.Driver;
using System.Linq;
namespace MongoDb.Ado.data
{
@ -73,11 +74,24 @@ namespace MongoDb.Ado.data
if (operation == "find")
{
var filter = string.IsNullOrWhiteSpace(json) ? FilterDefinition<BsonDocument>.Empty : BsonDocument.Parse(json);
var document = collection.Find(filter).FirstOrDefault();
return document;
// 设置投影排除 "_id" 字段,确保返回的结果不包含 _id 字段
var projection = Builders<BsonDocument>.Projection.Exclude("_id");
// 执行查询并限制返回一条记录
var document = collection.Find(filter).Project(projection).FirstOrDefault();
// 如果查询到结果且文档非空,则获取第一个字段的值
if (document != null && document.Elements.Any())
{
var firstElement = document.Elements.First(); // 获取第一个字段(列)
return firstElement.Value; // 返回该字段的值
}
return null; // 如果没有结果或没有字段,返回 null
}
throw new NotSupportedException("只支持 find 操作。");
return null;
}
protected override DbDataReader ExecuteDbDataReader(CommandBehavior behavior)

View File

@ -21,18 +21,29 @@ namespace MongoDbTest
private static void MongoDbCommandTest()
{
var connection = new MongoDbConnection(DbHelper.SqlSugarConnectionString);
connection.Open();
MongoDbCommand mongoDbCommand = new MongoDbCommand(" find b { age: { $gt: 31 } }", connection);
using (var reader = mongoDbCommand.ExecuteReader())
{
while (reader.Read())
//ExecuteReader
{
var connection = new MongoDbConnection(DbHelper.SqlSugarConnectionString);
connection.Open();
MongoDbCommand mongoDbCommand = new MongoDbCommand(" find b { age: { $gt: 31 } }", connection);
using (var reader = mongoDbCommand.ExecuteReader())
{
var name=reader.GetString("name");
var age = reader.GetInt32("age");
while (reader.Read())
{
var name = reader.GetString("name");
var age = reader.GetInt32("age");
}
}
connection.Close();
}
//ExecuteScalar
{
var connection = new MongoDbConnection(DbHelper.SqlSugarConnectionString);
connection.Open();
MongoDbCommand mongoDbCommand = new MongoDbCommand(" find b { age: { $gt: 31 } }", connection);
var value=mongoDbCommand.ExecuteScalar();
connection.Close();
}
connection.Close();
}
private static void MongoDbConnectionTest()