[Redis Chapter 7] Set

A set type is an unordered collection that performs operations such as adding, deleting, or judging the existence of an element in that type. Because the internal redis is implemented using a hash table with a null value, the operation has a time complexity of O (1) and a maximum of 2^32-1 strings stored.

Duplicate elements are not allowed in the set set, and another advantage of the set type in function is that it can be set, intersect, and set in difference compared to the list type.

Sadd

129.223.248.154:6379> Sadd Students Tim
(integer) 1
129.223.248.154:6379> Sadd students Tim Ben
(integer) 1

Srem

129.223.248.154:6379> Srem Student Tim
(integer) 0
129.223.248.154:6379> Srem Students Tim
(integer) 1

Smembers, Sismember

129.223.248.154:6379> smembers Students
1) "Ben"
129.223.248.154:6379> Sismember students Ben
(integer) 1
129.223.248.154:6379> Sismember Students Tim
(integer) 0

Sdiff difference Set

129.223.248.154:6379> sadd Setdiffa 1 2 3
(integer) 3
129.223.248.154:6379> Sadd SETDIFFB 2 3 4
(integer) 3
129.223.248.154:6379> sdiff Setdiffa SETDIFFB
1) "1"

Sinter intersection

129.223.248.154:6379> sadd Setintera 1 2 3
(integer) 3
129.223.248.154:6379> Sadd Setinterb 2 3 4
(integer) 3
129.223.248.154:6379> sinter setintera setinterb
1) "2"
2) "3"

Sunion and set

129.223.248.154:6379> sadd Setuniona 1 2 3
(integer) 3
129.223.248.154:6379> Sadd setunionb 2 4 6
(integer) 3
129.223.248.154:6379> sunion Setuniona setunionb
1) "1"
2) "2"
3) "3"
4) "4"
5) "6"

SCard Total number of collections

129.223.248.154:6379> SCard Students
(integer) 1
129.223.248.154:6379> smembers Students
1) "Ben"
129.223.248.154:6379> Srandmember Students
"Ben."
129.223.248.154:6379> Sadd Students Mike
(integer) 1
129.223.248.154:6379> Srandmember Students
"Ben."
129.223.248.154:6379> Srandmember Students
"Mike."
129.223.248.154:6379> Srandmember Students
"Mike."
129.223.248.154:6379> Sadd Memebrs a b C
(integer) 3
129.223.248.154:6379> Srandmember Students 2
1) "Ben"
2) "Mike"

Srandmember

129.223.248.154:6379> Sadd letters a b C
(integer) 3
129.223.248.154:6379> srandmember Letters 2
1) "B"
2) "C"

Spop

129.223.248.154:6379> Spop Letters
"B"
129.223.248.154:6379> smembers Letters
1) "A"
2) "C"
129.223.248.154:6379>

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[Redis Chapter 7] Set