C# - Notion API - Query, Filter database

1. Introduction

• Notion은 페이지, 데이터베이스 등에 대해 REST API를 지원한다.
  • API 접근을 하려면 Database 및 API 키가 필요하다.
    키를 얻는 방법에 대해서는 Build your first integration을 참조한다.
  • Notion의 API Reference는 NOTION API - Introduction을 참조한다.
• 여기서는 다음 항목을 다룬다.
  1. Query a database
  2. Paginated query
  3. Filter database entries

2. Database to perform

• DB 조회 및 필터 방법에 앞서, 테스트를 수행할 DB의 형태는 아래와 같다.
  

  

  • 선택으로 명명되어 있는 select 항목의 옵션은 아래와 같다.
    

    

• DB 작업 수행 간 JSON 형식의 Response object를 HTTP body에 실어 전송받게 된다.

• Reference 페이지를 참조하여 구현한 JSON object의 형태는 아래와 같다.

  Response (펼치기 / 접기)

    using NotionAPI.Objects;
  
    namespace NotionAPI;
  
    // https://developers.notion.com/reference/intro#responses 에 따라 작성
    public class NotionResponse
    {
        // 추가로 더 읽을 수 있는 데이터가 있는지
        public bool has_more { get; set; }
  
        // has_more가 true인 경우 다음 시작점
        public string? next_cursor { get; set; }
  
        public string? @object { get; set; }
  
        // 데이터가 들어감
        public List<PageInformation>? results { get; set; }
  
        // results의 데이터 형식
        public string? type { get; set; }
    }

  Paginated request (펼치기 / 접기)

    using System.Text.Json.Serialization;
  
    using NotionAPI.Objects;
  
    namespace NotionAPI;
  
    // https://developers.notion.com/reference/intro#parameters-for-paginated-requests 에 따라 작성
    public class PaginatedRequest
    {
        // 기본값 및 최대값은 100
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
        public int page_size { get; set; }
  
        // 시작점이 정의되지 않으면 처음부터 조회
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public string? start_cursor { get; set; }
    }

  PageInformation (펼치기 / 접기)

    using System.Text.Json.Serialization;
  
    namespace NotionAPI.Objects;
  
    // https://developers.notion.com/reference/page 에 따라 작성
    public class PageInformation
    {
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public string? @object { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public string? id { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
        public DateTime created_time { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public User? created_by { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
        public DateTime last_edited_time { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public User? last_edited_by { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
        public bool archived { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public object? icon { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public object? cover { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public Dictionary<string, PageProperty>? properties { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public Parent? parent { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public string? url { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public string? public_url { get; set; }
    }

  PageProperty (펼치기 / 접기)

    using System.Text.Json;
    using System.Text.Json.Serialization;
  
    namespace NotionAPI.Objects;
  
    // https://developers.notion.com/reference/page-property-values 에 따라 작성
    [JsonConverter(typeof(PagePropertyConverter))]
    public class PageProperty
    {
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public string? id { get; set; }
    }
  
    public sealed class PageSelect : PageProperty
    {
        public Select? select { get; set; }
    }
  
    public sealed class PageTitle : PageProperty
    {
        public List<RichText>? title { get; set; }
    }
  
    public class PagePropertyConverter : JsonConverter<PageProperty>
    {
        public override PageProperty? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
        {
            var jsonDoc = JsonDocument.ParseValue(ref reader);
            if (jsonDoc.RootElement.TryGetProperty("type", out var typeName))
            {
                return typeName.GetString() switch
                {
                    "select" => JsonSerializer.Deserialize<PageSelect>(jsonDoc),
                    "title" => JsonSerializer.Deserialize<PageTitle>(jsonDoc),
                    _ => null
                };
            }
  
            return null;
        }
  
        public override void Write(Utf8JsonWriter writer, PageProperty value, JsonSerializerOptions options)
        {
            switch (value)
            {
                case PageSelect select:
                    JsonSerializer.Serialize(writer, select);
                    break;
  
                case PageTitle title:
                    JsonSerializer.Serialize(writer, title);
                    break;
            }
        }
    }

  User (펼치기 / 접기)

    using System.Text.Json.Serialization;
  
    namespace NotionAPI.Objects;
  
    // https://developers.notion.com/reference/user 에 따라 작성
    [JsonPolymorphic(TypeDiscriminatorPropertyName = "type")]
    [JsonDerivedType(typeof(People), typeDiscriminator: "person")]
    [JsonDerivedType(typeof(Bots), typeDiscriminator: "bot")]
    public class User
    {
        public string? @object { get; set; }
        public string? id { get; set; }
        public string? name { get; set; }
        public string? avatar_url { get; set; }
    }
  
    public sealed class People : User
    {
        public object? person { get; set; }
    }
  
    public sealed class Bots : User
    {
        public object? bot { get; set; }
    }

  Parent (펼치기 / 접기)

    using System.Text.Json.Serialization;
  
    namespace NotionAPI.Objects;
  
    // https://developers.notion.com/reference/parent-object 에 따라 작성
    [JsonPolymorphic(TypeDiscriminatorPropertyName = "type")]
    [JsonDerivedType(typeof(DatabaseParent), typeDiscriminator: "database_id")]
    [JsonDerivedType(typeof(PageParent), typeDiscriminator: "page_id")]
    [JsonDerivedType(typeof(WorkspaceParent), typeDiscriminator: "workspace")]
    [JsonDerivedType(typeof(BlockParent), typeDiscriminator: "block_id")]
    public class Parent
    {
    }
  
    public sealed class DatabaseParent : Parent
    {
        public string? database_id { get; set; }
    }
  
    public sealed class PageParent : Parent
    {
        public string? page_id { get; set; }
    }
  
    public sealed class WorkspaceParent : Parent
    {
        public bool workspace { get; set; } = true;
    }
  
    public sealed class BlockParent : Parent
    {
        public string? block_id { get; set; }
    }

  RichText (펼치기 / 접기)

    using System.Text.Json.Serialization;
  
    namespace NotionAPI.Objects;
  
    // https://developers.notion.com/reference/rich-text 에 따라 작성
    [JsonPolymorphic(TypeDiscriminatorPropertyName = "type")]
    [JsonDerivedType(typeof(RichTextWithText), typeDiscriminator: "text")]
    [JsonDerivedType(typeof(RichTextWithMention), typeDiscriminator: "mention")]
    [JsonDerivedType(typeof(RichTextWithEquation), typeDiscriminator: "equation")]
    public class RichText
    {
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public Annotations? annotations { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public string? plain_text { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public string? href { get; set; }
    }
  
    public sealed class RichTextWithText : RichText
    {
        public Text? text { get; set; }
    }
  
    public sealed class RichTextWithMention : RichText
    {
        public object? mention { get; set; }
    }
  
    public sealed class RichTextWithEquation : RichText
    {
        public object? equation { get; set; }
    }
  
    public class Annotations
    {
        public bool bold { get; set; }
        public bool italic { get; set; }
        public bool strikethrough { get; set; }
        public bool underline { get; set; }
        public bool code { get; set; }
        public string? color { get; set; } = "default";
    }
  
    public class Text
    {
        public string? content { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public Link? link { get; set; }
    }
  
    public class Link
    {
        public string? url { get; set; }
    }

  Select (펼치기 / 접기)

    using System.Text.Json.Serialization;
  
    namespace NotionAPI.Objects;
  
    // https://developers.notion.com/reference/property-object#select 에 따라 작성
    public class Select
    {
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public string? id { get; set; }
  
        public string? name { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public string? color { get; set; }
    }

  Filter (펼치기 / 접기)

    using System.Text.Json.Serialization;
  
    namespace NotionAPI.Objects;
  
    // https://developers.notion.com/reference/post-database-query 에 따라 작성
    public class DatabaseFilterEntry
    {
        public DatabaseFilter? filter { get; set; }
    }
  
    public class DatabaseFilter
    {
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public List<DatabaseFilter>? and { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public List<DatabaseFilter>? or { get; set; }
  
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public string? property { get; set; }
  
        // Filter 테스트용으로 select만 작성
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public DatabaseSelect? select { get; set; }
    }

3. Query a database

• Database query 및 수신 데이터에 대한 deserialize 방법은 아래와 같다.

• 각 DB 데이터는 Page로 정의되어 있으며, NotionResponse.results 속성에 들어있다.

    using System.Text.Json;
    using NotionAPI;
  
    private static void Main(string[] args)
    {
        string baseUri = $"https://api.notion.com/v1/databases";
        string databaseKey = "데이터베이스 키";
        string APIKey = "API 키";
  
        DefaultQuery(baseUri, databaseKey, APIKey);
    }

    private static bool DefaultQuery(string baseUri, string databaseKey, string APIKey)
    {
        HttpClient client = new();
  
        // https://developers.notion.com/reference/post-database-query 문서 내용에 따라 Post로 request 작성
        var request = new HttpRequestMessage(HttpMethod.Post, $"{baseUri}/{databaseKey}/query");
        request.Headers.Add("Authorization", $"Bearer {APIKey}");
        request.Headers.Add("Notion-Version", "2022-06-28");
  
        var response = client.Send(request);
  
        // StatusCode를 포함한 Header 출력
        Console.WriteLine(response);
        // JSON 형식의 Body 출력
        var content = new StreamReader(response.Content.ReadAsStream()).ReadToEnd();
        Console.WriteLine(content);
  
        // Parsing
        var parsed = JsonSerializer.Deserialize<NotionResponse>(content);
  
        return response.StatusCode == System.Net.HttpStatusCode.OK;
    }

• 수신되는 데이터는 아래와 같다.

  Header (펼치기 / 접기)

    StatusCode: 200, ReasonPhrase: 'OK', Version: 1.1, Content: System.Net.Http.HttpConnectionResponseContent, Headers:
    {
          Date: Thu, 11 Apr 2024 03:49:25 GMT
          Transfer-Encoding: chunked
          Connection: keep-alive
          X-Powered-By: Express
          x-notion-request-id: 194c0ee9-3e9b-4f4a-8211-f3cd9bcbe1c3
          ETag: W/"e61-PzQqcDDUuvycY2625lPZsTjUYGY"
          Vary: Accept-Encoding
          CF-Cache-Status: DYNAMIC
          Set-Cookie: __cf_bm=1GEQzcVYQxc.MsKcqNj6k1uK5hwv5WLPWqIQ8sBHocA-1712807365-1.0.1.1-SoLy98KrforOujB8WD0Kghxolf8NSP6K.t55g7Hx4u6Di43onO8eIV0CnLZRPD60ANSwA1VxMBVBT06eO.f_ag; path=/; expires=Thu, 11-Apr-24 04:19:25 GMT; domain=.notion.com; HttpOnly; Secure
          Server: cloudflare
          CF-RAY: 872801b08bdcc10c-ICN
          Content-Type: application/json; charset=utf-8
    }

  Body (펼치기 / 접기)

    {
      "object": "list",
      "results": [
        {
          "object": "page",
          "id": "Page id",
          "created_time": "2024-04-03T23:32:00.000Z",
          "last_edited_time": "2024-04-03T23:32:00.000Z",
          "created_by": {
            "object": "user",
            "id": "유저 id"
          },
          "last_edited_by": {
            "object": "user",
            "id": "유저 id"
          },
          "cover": null,
          "icon": null,
          "parent": {
            "type": "database_id",
            "database_id": "DB id"
          },
          "archived": false,
          "in_trash": false,
          "properties": {
            "선택": {
              "id": "sKnP",
              "type": "select",
              "select": {
                "id": "CsLi",
                "name": "2",
                "color": "gray"
              }
            },
            "이름": {
              "id": "title",
              "type": "title",
              "title": [
                {
                  "type": "text",
                  "text": {
                    "content": "4",
                    "link": null
                  },
                  "annotations": {
                    "bold": false,
                    "italic": false,
                    "strikethrough": false,
                    "underline": false,
                    "code": false,
                    "color": "default"
                  },
                  "plain_text": "4",
                  "href": null
                }
              ]
            }
          },
          "url": "https://www.notion.so/4-Page id",
          "public_url": null
        },
        {
          "object": "page",
          "id": "Page id",
          "created_time": "2024-04-03T23:32:00.000Z",
          "last_edited_time": "2024-04-08T22:31:00.000Z",
          "created_by": {
            "object": "user",
            "id": "유저 id"
          },
          "last_edited_by": {
            "object": "user",
            "id": "유저 id"
          },
          "cover": null,
          "icon": null,
          "parent": {
            "type": "database_id",
            "database_id": "DB id"
          },
          "archived": false,
          "in_trash": false,
          "properties": {
            "선택": {
              "id": "sKnP",
              "type": "select",
              "select": {
                "id": "@:oT",
                "name": "1",
                "color": "yellow"
              }
            },
            "이름": {
              "id": "title",
              "type": "title",
              "title": [
                {
                  "type": "text",
                  "text": {
                    "content": "3",
                    "link": null
                  },
                  "annotations": {
                    "bold": false,
                    "italic": false,
                    "strikethrough": false,
                    "underline": false,
                    "code": false,
                    "color": "default"
                  },
                  "plain_text": "3",
                  "href": null
                }
              ]
            }
          },
          "url": "https://www.notion.so/3-Page id",
          "public_url": null
        },
        {
          "object": "page",
          "id": "Page id",
          "created_time": "2024-04-03T23:32:00.000Z",
          "last_edited_time": "2024-04-03T23:32:00.000Z",
          "created_by": {
            "object": "user",
            "id": "유저 id"
          },
          "last_edited_by": {
            "object": "user",
            "id": "유저 id"
          },
          "cover": null,
          "icon": null,
          "parent": {
            "type": "database_id",
            "database_id": "DB id"
          },
          "archived": false,
          "in_trash": false,
          "properties": {
            "선택": {
              "id": "sKnP",
              "type": "select",
              "select": {
                "id": "CsLi",
                "name": "2",
                "color": "gray"
              }
            },
            "이름": {
              "id": "title",
              "type": "title",
              "title": [
                {
                  "type": "text",
                  "text": {
                    "content": "2",
                    "link": null
                  },
                  "annotations": {
                    "bold": false,
                    "italic": false,
                    "strikethrough": false,
                    "underline": false,
                    "code": false,
                    "color": "default"
                  },
                  "plain_text": "2",
                  "href": null
                }
              ]
            }
          },
          "url": "https://www.notion.so/2-Page id",
          "public_url": null
        },
        {
          "object": "page",
          "id": "Page id",
          "created_time": "2024-04-03T23:31:00.000Z",
          "last_edited_time": "2024-04-08T22:31:00.000Z",
          "created_by": {
            "object": "user",
            "id": "유저 id"
          },
          "last_edited_by": {
            "object": "user",
            "id": "유저 id"
          },
          "cover": null,
          "icon": null,
          "parent": {
            "type": "database_id",
            "database_id": "DB id"
          },
          "archived": false,
          "in_trash": false,
          "properties": {
            "선택": {
              "id": "sKnP",
              "type": "select",
              "select": {
                "id": "@:oT",
                "name": "1",
                "color": "yellow"
              }
            },
            "이름": {
              "id": "title",
              "type": "title",
              "title": [
                {
                  "type": "text",
                  "text": {
                    "content": "1",
                    "link": null
                  },
                  "annotations": {
                    "bold": false,
                    "italic": false,
                    "strikethrough": false,
                    "underline": false,
                    "code": false,
                    "color": "default"
                  },
                  "plain_text": "1",
                  "href": null
                }
              ]
            }
          },
          "url": "https://www.notion.so/1-Page id",
          "public_url": null
        }
      ],
      "next_cursor": null,
      "has_more": false,
      "type": "page_or_database",
      "page_or_database": {},
      "request_id": "194c0ee9-3e9b-4f4a-8211-f3cd9bcbe1c3"
    }

4. Paginated query

• Database query는 결과를 최대 100개 출력한다.

• Query를 작성할 때 page_size 및 start_cursor 속성을 이용해 출력할 결과 수와 시작점을 설정할 수 있으며, body에 실어 보낸다.

• Response data 이후 추가 데이터가 있는지 response의 has_more, next_cursor 속성을 이용해 확인할 수 있다.

    using System.Net.Http.Json;
    using System.Text.Json;
    using NotionAPI;
  
    private static void Main(string[] args)
    {
        string baseUri = $"https://api.notion.com/v1/databases";
        string databaseKey = "데이터베이스 키";
        string APIKey = "API 키";
  
        ContinuedPaginatedQuery(baseUri, databaseKey, APIKey);
    }

    private static bool ContinuedPaginatedQuery(string baseUri, string databaseKey, string APIKey, int pageSize = 100, string? startCursor = null)
    {
        bool hasMore = false;
        HttpClient client = new();
  
        do
        {
            // https://developers.notion.com/reference/post-database-query 문서 내용에 따라 Post로 request 작성
            var request = new HttpRequestMessage(HttpMethod.Post, $"{baseUri}/{databaseKey}/query");
            request.Headers.Add("Authorization", $"Bearer {APIKey}");
            request.Headers.Add("Notion-Version", "2022-06-28");
            // https://developers.notion.com/reference/intro#pagination 에 따라 Query 옵션 추가
            request.Content = JsonContent.Create(new PaginatedRequest { page_size = pageSize, start_cursor = startCursor });
  
            var response = client.Send(request);
  
            if (response.StatusCode != System.Net.HttpStatusCode.OK) return false;
  
            // StatusCode를 포함한 Header 출력
            Console.WriteLine(response);
            // JSON 형식의 Body 출력
            string content = new StreamReader(response.Content.ReadAsStream()).ReadToEnd();
            Console.WriteLine(content);
  
            // 추가 데이터가 더 있는지, 다음 시작 위치는 어디인지 설정
            var parsed = JsonSerializer.Deserialize<NotionResponse>(content);
            if (parsed is not null)
            {
                hasMore = parsed.has_more;
                startCursor = parsed.next_cursor;
            }
        }
        while (hasMore);
  
        return true;
    }

• 수신되는 데이터는 아래와 같다.

  Header (펼치기 / 접기)

    StatusCode: 200, ReasonPhrase: 'OK', Version: 1.1, Content: System.Net.Http.HttpConnectionResponseContent, Headers:
    {
          Date: Thu, 11 Apr 2024 04:07:06 GMT
          Transfer-Encoding: chunked
          Connection: keep-alive
          X-Powered-By: Express
          x-notion-request-id: 8c79815c-0606-4769-a5b4-684f2f0e9760
          ETag: W/"e61-/VQYr+yZIM6pyY7zKG/399nxhtE"
          Vary: Accept-Encoding
          CF-Cache-Status: DYNAMIC
          Set-Cookie: __cf_bm=2Spi9DBRNAUrZMbWAtdVOz_NMImQEZmN.9HHGUndcDk-1712808426-1.0.1.1-hl565ncYHWNLYSN_142GQ7Fz1hUUklLqh00uVtJBHJmPdK7F2BODmNHkkBR5KbJH0yh4flz67D6scgTy0dvT2Q; path=/; expires=Thu, 11-Apr-24 04:37:06 GMT; domain=.notion.com; HttpOnly; Secure
          Server: cloudflare
          CF-RAY: 87281b963b1da7b4-ICN
          Content-Type: application/json; charset=utf-8
    }

  Body (펼치기 / 접기)

    {
      "object": "list",
      "results": [
        {
          "object": "page",
          "id": "Page id",
          "created_time": "2024-04-03T23:32:00.000Z",
          "last_edited_time": "2024-04-03T23:32:00.000Z",
          "created_by": {
            "object": "user",
            "id": "유저 id"
          },
          "last_edited_by": {
            "object": "user",
            "id": "유저 id"
          },
          "cover": null,
          "icon": null,
          "parent": {
            "type": "database_id",
            "database_id": "DB id"
          },
          "archived": false,
          "in_trash": false,
          "properties": {
            "선택": {
              "id": "sKnP",
              "type": "select",
              "select": {
                "id": "CsLi",
                "name": "2",
                "color": "gray"
              }
            },
            "이름": {
              "id": "title",
              "type": "title",
              "title": [
                {
                  "type": "text",
                  "text": {
                    "content": "4",
                    "link": null
                  },
                  "annotations": {
                    "bold": false,
                    "italic": false,
                    "strikethrough": false,
                    "underline": false,
                    "code": false,
                    "color": "default"
                  },
                  "plain_text": "4",
                  "href": null
                }
              ]
            }
          },
          "url": "https://www.notion.so/4-Page id",
          "public_url": null
        },
        {
          "object": "page",
          "id": "Page id",
          "created_time": "2024-04-03T23:32:00.000Z",
          "last_edited_time": "2024-04-08T22:31:00.000Z",
          "created_by": {
            "object": "user",
            "id": "유저 id"
          },
          "last_edited_by": {
            "object": "user",
            "id": "유저 id"
          },
          "cover": null,
          "icon": null,
          "parent": {
            "type": "database_id",
            "database_id": "DB id"
          },
          "archived": false,
          "in_trash": false,
          "properties": {
            "선택": {
              "id": "sKnP",
              "type": "select",
              "select": {
                "id": "@:oT",
                "name": "1",
                "color": "yellow"
              }
            },
            "이름": {
              "id": "title",
              "type": "title",
              "title": [
                {
                  "type": "text",
                  "text": {
                    "content": "3",
                    "link": null
                  },
                  "annotations": {
                    "bold": false,
                    "italic": false,
                    "strikethrough": false,
                    "underline": false,
                    "code": false,
                    "color": "default"
                  },
                  "plain_text": "3",
                  "href": null
                }
              ]
            }
          },
          "url": "https://www.notion.so/3-Page id",
          "public_url": null
        },
        {
          "object": "page",
          "id": "Page id",
          "created_time": "2024-04-03T23:32:00.000Z",
          "last_edited_time": "2024-04-03T23:32:00.000Z",
          "created_by": {
            "object": "user",
            "id": "유저 id"
          },
          "last_edited_by": {
            "object": "user",
            "id": "유저 id"
          },
          "cover": null,
          "icon": null,
          "parent": {
            "type": "database_id",
            "database_id": "DB id"
          },
          "archived": false,
          "in_trash": false,
          "properties": {
            "선택": {
              "id": "sKnP",
              "type": "select",
              "select": {
                "id": "CsLi",
                "name": "2",
                "color": "gray"
              }
            },
            "이름": {
              "id": "title",
              "type": "title",
              "title": [
                {
                  "type": "text",
                  "text": {
                    "content": "2",
                    "link": null
                  },
                  "annotations": {
                    "bold": false,
                    "italic": false,
                    "strikethrough": false,
                    "underline": false,
                    "code": false,
                    "color": "default"
                  },
                  "plain_text": "2",
                  "href": null
                }
              ]
            }
          },
          "url": "https://www.notion.so/2-Page id",
          "public_url": null
        },
        {
          "object": "page",
          "id": "Page id",
          "created_time": "2024-04-03T23:31:00.000Z",
          "last_edited_time": "2024-04-08T22:31:00.000Z",
          "created_by": {
            "object": "user",
            "id": "유저 id"
          },
          "last_edited_by": {
            "object": "user",
            "id": "유저 id"
          },
          "cover": null,
          "icon": null,
          "parent": {
            "type": "database_id",
            "database_id": "DB id"
          },
          "archived": false,
          "in_trash": false,
          "properties": {
            "선택": {
              "id": "sKnP",
              "type": "select",
              "select": {
                "id": "@:oT",
                "name": "1",
                "color": "yellow"
              }
            },
            "이름": {
              "id": "title",
              "type": "title",
              "title": [
                {
                  "type": "text",
                  "text": {
                    "content": "1",
                    "link": null
                  },
                  "annotations": {
                    "bold": false,
                    "italic": false,
                    "strikethrough": false,
                    "underline": false,
                    "code": false,
                    "color": "default"
                  },
                  "plain_text": "1",
                  "href": null
                }
              ]
            }
          },
          "url": "https://www.notion.so/1-Page id",
          "public_url": null
        }
      ],
      "next_cursor": null,
      "has_more": false,
      "type": "page_or_database",
      "page_or_database": {},
      "request_id": "8c79815c-0606-4769-a5b4-684f2f0e9760"
    }

5. Filter database entries

• Query를 작성할 때 원하는 데이터만을 얻기 위해 filter를 설정할 수 있으며, body에 실어 보낸다.

• 아래는 filter를 사용하는 간략한 예를 보여준다.

    using System.Net.Http.Json;
    using NotionAPI.Objects;
  
    private static void Main(string[] args)
    {
        string baseUri = $"https://api.notion.com/v1/databases";
        string databaseKey = "데이터베이스 키";
        string APIKey = "API 키";
  
        FilteredQuery(baseUri, databaseKey, APIKey);
    }

    private static bool FilteredQuery(string baseUri, string databaseKey, string APIKey)
    {
        HttpClient client = new();
  
        // https://developers.notion.com/reference/post-database-query 문서 내용에 따라 Post로 request 작성
        var request = new HttpRequestMessage(HttpMethod.Post, $"{baseUri}/{databaseKey}/query");
        request.Headers.Add("Authorization", $"Bearer {APIKey}");
        request.Headers.Add("Notion-Version", "2022-06-28");
        // https://developers.notion.com/reference/post-database-query 에 따라 Query 옵션 추가
        request.Content = JsonContent.Create(new DatabaseFilterEntry() { filter = new DatabaseFilter() { property = "선택", select = new() { equals = "1" } } });
  
        var response = client.Send(request);
  
        // StatusCode를 포함한 Header 출력
        Console.WriteLine(response);
        // JSON 형식의 Body 출력
        Console.WriteLine(new StreamReader(response.Content.ReadAsStream()).ReadToEnd());
  
        return response.StatusCode == System.Net.HttpStatusCode.OK;
    }

• 수신되는 데이터는 아래와 같다.

  Header (펼치기 / 접기)

    StatusCode: 200, ReasonPhrase: 'OK', Version: 1.1, Content: System.Net.Http.HttpConnectionResponseContent, Headers:
    {
          Date: Thu, 11 Apr 2024 04:35:10 GMT
          Transfer-Encoding: chunked
          Connection: keep-alive
          X-Powered-By: Express
          x-notion-request-id: bc9cdbae-c4b7-41b5-86a7-36f550bfbd0a
          ETag: W/"785-Ilk7yABKhwyb8FyoM2KvzbVrBM8"
          Vary: Accept-Encoding
          CF-Cache-Status: DYNAMIC
          Set-Cookie: __cf_bm=FuSAYsBTjeG8E315.zOIGZOglNHAYsYW9jD9GmFd2nM-1712810110-1.0.1.1-c3w5GCldRBChkqK2uWFskLYvREjTcCiiwlQPgvrhbbblMqJba0Z1vtpEA0bfIhSPjNQlS3NYnIPe28BghxTYBw; path=/; expires=Thu, 11-Apr-24 05:05:10 GMT; domain=.notion.com; HttpOnly; Secure
          Server: cloudflare
          CF-RAY: 872844b2ab0830ce-ICN
          Content-Type: application/json; charset=utf-8
    }

  Body (펼치기 / 접기)

    {
      "object": "list",
      "results": [
        {
          "object": "page",
          "id": "Page id",
          "created_time": "2024-04-03T23:32:00.000Z",
          "last_edited_time": "2024-04-08T22:31:00.000Z",
          "created_by": {
            "object": "user",
            "id": "유저 id"
          },
          "last_edited_by": {
            "object": "user",
            "id": "유저 id"
          },
          "cover": null,
          "icon": null,
          "parent": {
            "type": "database_id",
            "database_id": "DB id"
          },
          "archived": false,
          "in_trash": false,
          "properties": {
            "선택": {
              "id": "sKnP",
              "type": "select",
              "select": {
                "id": "@:oT",
                "name": "1",
                "color": "yellow"
              }
            },
            "이름": {
              "id": "title",
              "type": "title",
              "title": [
                {
                  "type": "text",
                  "text": {
                    "content": "3",
                    "link": null
                  },
                  "annotations": {
                    "bold": false,
                    "italic": false,
                    "strikethrough": false,
                    "underline": false,
                    "code": false,
                    "color": "default"
                  },
                  "plain_text": "3",
                  "href": null
                }
              ]
            }
          },
          "url": "https://www.notion.so/3-Page id",
          "public_url": null
        },
        {
          "object": "page",
          "id": "Page id",
          "created_time": "2024-04-03T23:31:00.000Z",
          "last_edited_time": "2024-04-08T22:31:00.000Z",
          "created_by": {
            "object": "user",
            "id": "유저 id"
          },
          "last_edited_by": {
            "object": "user",
            "id": "유저 id"
          },
          "cover": null,
          "icon": null,
          "parent": {
            "type": "database_id",
            "database_id": "DB id"
          },
          "archived": false,
          "in_trash": false,
          "properties": {
            "선택": {
              "id": "sKnP",
              "type": "select",
              "select": {
                "id": "@:oT",
                "name": "1",
                "color": "yellow"
              }
            },
            "이름": {
              "id": "title",
              "type": "title",
              "title": [
                {
                  "type": "text",
                  "text": {
                    "content": "1",
                    "link": null
                  },
                  "annotations": {
                    "bold": false,
                    "italic": false,
                    "strikethrough": false,
                    "underline": false,
                    "code": false,
                    "color": "default"
                  },
                  "plain_text": "1",
                  "href": null
                }
              ]
            }
          },
          "url": "https://www.notion.so/1-Page id",
          "public_url": null
        }
      ],
      "next_cursor": null,
      "has_more": false,
      "type": "page_or_database",
      "page_or_database": {},
      "request_id": "bc9cdbae-c4b7-41b5-86a7-36f550bfbd0a"
    }

6. 참조 자료

• NOTION API - Introduction
• Build your first integration
• Query a database
• Paginated query
• Filter database entries
• System.Text.Json을 사용하여 파생 클래스의 속성을 직렬화하는 방법
• System.Text.Json을 사용하여 속성을 무시하는 방법
• .NET에서 JSON serialization(마샬링)용 사용자 지정 변환기를 작성하는 방법