Python全棧MongoDB資料庫（聚合、二進位制、GridFS、pymongo模組）

from pymongo import MongoClient 

#建立連線
conn = MongoClient(`localhost`,27017)

#建立資料庫物件
db = conn.stu 

#建立集合物件
myset = db.class4 

print(dir(myset))

# 插入操作
myset.insert({`name`:`張鐵林`,`King`:`乾隆`})
myset.insert([{`name`:`張國立`,`King`:`康熙`},
    {`name`:`陳道明`,`King`:`康熙`}])
myset.insert_many([{`name`:`唐國強`,`King`:`雍正`},
    {`name`:`陳建斌`,`King`:`雍正`}])
myset.insert_one({`name`:`鄭少秋`,`King`:`乾隆`})
myset.save({`_id`:1,`name`:`聶遠`,`King`:`乾隆`}) 

# 查詢操作

cursor = myset.find({},{`_id`:0})

# i為每個文件對應的字典
for i in cursor:
    print(i[`name`],`--->`,i[`King`])

myset = db.class1 
# 操作符使用引號變為字串
cursor = myset.find({`age`:{`$gt`:30}},{`_id`:0})

cursor.limit(2)#獲取前兩個文件
cursor.skip(2) #跳過前兩個
cursor.sort([(`age`,-1),(`name`,1)]) #對遊標內容排序

for i in cursor:
    print(i)
print(cursor.next()) #獲取下一個文件


dic = {`$or`:[{`age`:{`$gt`:35}},{`gender`:`w`}]}
data = myset.find_one(dic,{`_id`:0})
print(data)

# 修改操作
myset.update({`name`:`張國立`},
    {`$set`:{`king_name`:`玄燁`}})

myset.update({`name`:`霍建華`},{`$set`:{`King`:`乾隆`}},
    upsert = True)

myset.update({`King`:`乾隆`},
    {`$set`:{`king_name`:`弘曆`}},multi = True)

myset.update_one({`King`:`康熙`},
    {`$set`:{`king_name`:`愛新覺羅玄燁`}})

myset.update_many({`King`:`雍正`},
    {`$set`:{`king_name`:`胤禛`}})

# 刪除操作

myset.remove({`King`:`康熙`})
myset.remove({`King`:`乾隆`},multi = False)

#查詢並刪除
print(myset.find_one_and_delete({`King`:`乾隆`}))


#關閉連線
conn.close()

from pymongo import MongoClient 

#建立連線
conn = MongoClient(`localhost`,27017)

#建立資料庫物件
db = conn[`stu`] 

myset = db[`class1`] 

# 刪除所有索引
myset.drop_indexes()

# 建立索引
index = myset.ensure_index(`name`)
# 建立複合索引
index = myset.ensure_index([(`name`,-1),(`age`,1)])
print(index)

# 刪除一個索引
myset.drop_index(`name_1`)

# 建立特殊索引
index = myset.ensure_index(`name`,name = "myIndex",
    unique = True,sparse = True)

# 檢視集合中的索引
for i in myset.list_indexes():
    print(i)

myset = db.class4 

l = [
    {`$group`:{`_id`:`$King`,`num`:{`$sum`:1}}},
    {`$match`:{`num`:{`$gt`:1}}}
]

cursor = myset.aggregate(l)
for i in cursor:
    print(i)

conn.close()

from pymongo import MongoClient 
import bson.binary 

conn = MongoClient(`localhost`,27017)
db = conn.images 
myset = db.img 

#儲存
f = open(`file.jpg`,`rb`)

#轉換為mongodb的二進位制資料儲存形式
content = bson.binary.Binary(f.read())

#插入到資料庫
myset.insert({`filename`:`file.jpg`,`data`:content})

#提取

data = myset.find_one({`filename`:`file.jpg`})

#通過字典獲取到資料庫內容寫入本地
with open(data[`filename`],`wb`) as f:
    f.write(data[`data`])

conn.close()

from pymongo import MongoClient 
#pymongo繫結的模組
import gridfs

conn = MongoClient(`localhost`,27017)
db = conn.grid 

#獲取gridfs物件
#fs綜合了fs.files  fs.chunks兩個集合的屬性內容
fs = gridfs.GridFS(db)

#查文件生產遊標
files = fs.find()

#獲取每一個檔案的物件
for file in files:
    print(file.filename)
    if file.filename == `file.jpg`:
        with open(file.filename,`wb`) as f:
            #從資料庫讀取出來
            data = file.read()
            #寫入本地
            f.write(data)

conn.close()