文字轉查詢的流程

使用 MongoDB 與 LangGraph 的 Text-to-Query Agent

Apoorva Joshi

Senior AI/ML Developer Advocate, MongoDB

Text-to-query

Text-to-query

Text-to-query

Text-to-query

Text-to-query

Text-to-query

Text-to-query：代理式方法

 

資料：MongoDB 風格！

 

結構化查詢語言（SQL）

SQL 查詢範例

SELECT *
FROM table
WHERE year>=1950
LIMIT 5

MongoDB Query API

類 JSON 輸入範例

{ "$and": [
              {"year": {"$gte": 1990}},
              {"year": {"$lt": 2000}}
          ]
}

MongoDB 查詢方法

• .find(), .insert(), .update(), .delete()

範例：movies 集合

_id	Title	Release Year	Cast	Genres
573a1396f29313caabce3d17	Larks on a String	1990	[Rudolf Hrusènskè, Vlastimil Brodskè]	[Comedy, Drama, Romance]
573a1398f29313caabceab72	The Witching of Ben Wagner	1990	[Sam Bottoms, Harriet Hall, Bettina Rae, Justin Gocke]	[Family]
...	...	...	[...]	[...]

單一篩選條件

query = {"genre": "Romance"}

單一篩選條件

query = {"genre": "Romance"}

_id	Title	Release Year	Cast	Genres
573a1390f29313caabcd6377	Wild and Woolly	1917	[Douglas Fairbanks, Eileen Percy, Calvert Carter, Charles Stevens]	[Comedy, Western, Romance]
573a1391f29313caabcd70b4	The Four Horsemen of the Apocalypse	1921	[Pomeroy Cannon, Josef Swickard, Bridgetta Clark, Rudolph Valentino]	[Drama, Romance, War]

多重篩選條件

query = { "$and": [
                    {"year": {"$gte": 1990}},
                    {"year": {"$lt": 2000}}
                  ]
        }

多重篩選條件

query = { "$and": [
                    {"year": {"$gte": 1990}},
                    {"year": {"$lt": 2000}}
                  ]
        }

_id	Title	Release Year	Cast	Genres
573a1396f29313caabce3d17	Larks on a String	1990	[Rudolf Hrusènskè, Vlastimil Brodskè]	[Comedy, Drama, Romance]
573a1398f29313caabceab72	The Witching of Ben Wagner	1990	[Sam Bottoms, Harriet Hall, Bettina Rae, Justin Gocke]	[Family]

Aggregation pipelines

db.<collection>.aggregate([
    {stage-1},
    {stage-2},
    {stage-3},
    {stage-4},
])

多步驟操作

query = [








]

多步驟操作

query = [

    { "$sort": { "released": -1 } },






]

• 依 released 排序

多步驟操作

query = [

    { "$sort": { "released": -1 } },

    { "$limit": 5 },




]

• 依 released 排序

• 取前 5 筆結果

多步驟操作

query = [

    { "$sort": { "released": -1 } },

    { "$limit": 5 },

    { "$project": { "title": 1,
                    "_id": 0 } }

]

• 依 released 排序

• 取前 5 筆結果

• 投影 "title" 欄位

多步驟操作

query = [

    { "$sort": { "released": -1 } },

    { "$limit": 5 },

    { "$project": { "title": 1,
                    "_id": 0 } }

]

• 依 released 排序

• 取前 5 筆結果

• 投影 "title" 欄位

Title
The Treasure
Knight of Cups
Sand Castles
Shut In
Dègradè

群組聚合

_id	Title	Release Year	Cast	Genres
573a1396f29313caabce3d17	Larks on a String	1990	[Rudolf Hrusènskè, Vlastimil Brodskè]	[Comedy, Drama, Romance]
573a1398f29313caabceab72	The Witching of Ben Wagner	1990	[Sam Bottoms, Harriet Hall, Bettina Rae, Justin Gocke]	[Family]
...	...	...	[...]	[...]

群組聚合

query = [

          { "$unwind": "$genres" },

          { "$group": {
                "_id": "$genres",
                "numMovies": { "$sum": 1 }
          }},

          { "$match": { "numMovies": { "$gte": 50 } } }

]

群組聚合

 

Genre	Count
Drama	12385
Comedy	6532
Romance	3318
Crime	2457
Thriller	2454
...	...

管線階段

• $match, $group, $facet, $geoNear, $lookup, $merge, $search, $sort...

運算子

• 比較：$eq, $gt, $gte, ...
• 數學：$add, $multiply, $divide...
• 陣列：$push, $reduce, ...
• 字串：$toUpper, $toLower, ...
• 時間：$dateAdd, $dateDiff, ...

一起來練習吧！

使用 MongoDB 與 LangGraph 的 Text-to-Query Agent