索引/查询 JSON 文档

将 JSON 文档添加到索引

import redis
from redis.commands.json.path import Path
import redis.commands.search.aggregation as aggregations
import redis.commands.search.reducers as reducers
from redis.commands.search.field import TextField, NumericField, TagField
from redis.commands.search.indexDefinition import IndexDefinition, IndexType
from redis.commands.search.query import NumericFilter, Query


r = redis.Redis(host='localhost', port=6379)
user1 = {
    "user":{
        "name": "Paul John",
        "email": "[email protected]",
        "age": 42,
        "city": "London"
    }
}
user2 = {
    "user":{
        "name": "Eden Zamir",
        "email": "[email protected]",
        "age": 29,
        "city": "Tel Aviv"
    }
}
user3 = {
    "user":{
        "name": "Paul Zamir",
        "email": "[email protected]",
        "age": 35,
        "city": "Tel Aviv"
    }
}

user4 = {
    "user":{
        "name": "Sarah Zamir",
        "email": "[email protected]",
        "age": 30,
        "city": "Paris"
    }
}
r.json().set("user:1", Path.root_path(), user1)
r.json().set("user:2", Path.root_path(), user2)
r.json().set("user:3", Path.root_path(), user3)
r.json().set("user:4", Path.root_path(), user4)

schema = (TextField("$.user.name", as_name="name"),TagField("$.user.city", as_name="city"), NumericField("$.user.age", as_name="age"))
r.ft().create_index(schema, definition=IndexDefinition(prefix=["user:"], index_type=IndexType.JSON))

b'OK'

搜索

简单搜索

r.ft().search("Paul")

Result{2 total, docs: [Document {'id': 'user:1', 'payload': None, 'json': '{"user":{"name":"Paul John","email":"[email protected]","age":42,"city":"London"}}'}, Document {'id': 'user:3', 'payload': None, 'json': '{"user":{"name":"Paul Zamir","email":"[email protected]","age":35,"city":"Tel Aviv"}}'}]}

过滤搜索结果

q1 = Query("Paul").add_filter(NumericFilter("age", 30, 40))
r.ft().search(q1)

Result{1 total, docs: [Document {'id': 'user:3', 'payload': None, 'json': '{"user":{"name":"Paul Zamir","email":"[email protected]","age":35,"city":"Tel Aviv"}}'}]}

分页和排序搜索结果

# Search for all users, returning 2 users at a time and sorting by age in descending order
offset = 0
num = 2
q = Query("*").paging(offset, num).sort_by("age", asc=False) # pass asc=True to sort in ascending order
r.ft().search(q)

Result{4 total, docs: [Document {'id': 'user:1', 'payload': None, 'age': '42', 'json': '{"user":{"name":"Paul John","email":"[email protected]","age":42,"city":"London"}}'}, Document {'id': 'user:3', 'payload': None, 'age': '35', 'json': '{"user":{"name":"Paul Zamir","email":"[email protected]","age":35,"city":"Tel Aviv"}}'}]}

计算项目总数

q = Query("*").paging(0, 0)
r.ft().search(q).total

4

使用 JSON Path 表达式进行投影

r.ft().search(Query("Paul").return_field("$.user.city", as_field="city")).docs

[Document {'id': 'user:1', 'payload': None, 'city': 'London'},
 Document {'id': 'user:3', 'payload': None, 'city': 'Tel Aviv'}]

聚合

req = aggregations.AggregateRequest("Paul").sort_by("@age")
r.ft().aggregate(req).rows

[[b'age', b'35'], [b'age', b'42']]

计算项目总数

# The group_by expects a string or list of strings to group the results before applying the aggregation function to
# each group. Passing an empty list here acts as `GROUPBY 0` which applies the aggregation function to the whole results
req = aggregations.AggregateRequest("*").group_by([], reducers.count().alias("total"))
r.ft().aggregate(req).rows

[[b'total', b'4']]