Redis GEO

Redis GEO It is mainly used to store geographic information , And operate the stored information , This function is available in Redis 3.2 Version added . Used to realize such as attachment location , Shake this kind of function that depends on Geographic Information , It is a great blessing for developers who need to implement these functions .

Redis GEO The operation methods are ：

• geoadd： Add geographic coordinates .
• geopos： Get the coordinates of the geographic location .
• geodist： Calculate the distance between two positions .
• georadius： According to the longitude and latitude coordinates given by the user to obtain the geographic location set within the specified range .
• georadiusbymember： According to a location stored in the location set, get the geographic location set within the specified range .
• geohash： Returns the... Of one or more location objects geohash value .

geoadd

geoadd Used to store a specified geospatial location , You can put one or more longitudes (longitude)、 latitude (latitude)、 Location name (member) Add to specified key in .

geoadd The syntax is as follows ：geoadd key longitude latitude member [longitude latitude member ...]

The following table shows the longitude and latitude of several cities

127.0.0.1:6379> geoadd cities 117.17  31.52  hefei

(integer) 1

127.0.0.1:6379> geoadd cities 117.02 30.31 anqing

(integer) 1

127.0.0.1:6379> geoadd cities 116.47 33.57 huaibei

(integer) 1

127.0.0.1:6379> geoadd cities 116.58 33.38 suzhou

(integer) 1

geopos

geopos Used from a given key All specified names are returned in (member) The location of （ Longitude and latitude ）, There is no return nil.

geopos The syntax is as follows ：geopos key member [member ...]

127.0.0.1:6379> geopos cities hefei

1) 1) "117.17000216245651245"

   2) "31.519999022318963"

127.0.0.1:6379> geopos cities anqing

1) 1) "117.02000230550765991"

   2) "30.30999918248532765"

geodist

geodist Used to return the distance between two given positions .

geodist The syntax is as follows ：geodist key member1 member2 [m|km|ft|mi]

127.0.0.1:6379> geodist cities hefei anqing km

"135.3428"

georadius、georadiusbymember

georadius Centered on a given latitude and longitude , Return key contains position elements , All position elements whose distance from the center does not exceed the given maximum distance .

georadiusbymember and GEORADIUS command , Can find the elements in the specified range , however georadiusbymember The center point of is determined by a given location element , Instead of using longitude and latitude to determine the center point .

georadius And georadiusbymember The syntax is as follows ：

GEORADIUS key longitude latitude radius m|km|ft|mi [WITHCOORD] [WITHDIST] [WITHHASH] [COUNT count] [ASC|DESC] [STORE key] [STOREDIST key]
GEORADIUSBYMEMBER key member radius m|km|ft|mi [WITHCOORD] [WITHDIST] [WITHHASH] [COUNT count] [ASC|DESC] [STORE key] [STOREDIST key]

Parameter description ：

• • m ： rice , Default unit .
  • km ： km .
  • mi ： miles .
  • ft ： feet .
  • WITHDIST: While returning location elements , Return the distance between the location element and the center as well .
  • WITHCOORD: Return the longitude and dimension of the location element as well .
  • WITHHASH: With 52 Bit signed integer form , Return the location element through the original geohash Encoded ordered set score . This option is mainly used for underlying applications or debugging , It doesn't really work .
  • COUNT Limit the number of records returned .
  • ASC: The search results are sorted from near to far .
  • DESC: The search results are sorted from far to near .

127.0.0.1:6379> georadius cities 117 30 200 km withcoord

1) 1) "anqing"

   2) 1) "117.02000230550765991"

      2) "30.30999918248532765"

2) 1) "hefei"

   2) 1) "117.17000216245651245"

      2) "31.519999022318963"

geohash

Redis GEO Use geohash To save the coordinates of the geographic location .

geohash Used to get one or more location elements geohash value .

geohash The syntax is as follows ：GEOHASH key member [member ...]

127.0.0.1:6379> geohash cities hefei anqing suzhou

1) "wte766096c0"

2) "wt7hqvg2e90"

3) "wtfvuuduwg0"

127.0.0.1:6379> type cities

zset

Delete geographic information

zrem key member

GEO There is no command to delete members , But because GEO The underlying implementation is zset, So you can borrow zrem Command to delete geographic location information .