1. Set
1.1 sadd
1.1.1 基本信息
SADD key member [member ...]
summary: Add one or more members to a set
since: 1.0.0
Add the specified members to the set stored at key. Specified members that are already a member of this set are ignored. If key does not exist, a new set is created before adding the specified members.
将指定的成员添加到按键存储的集合中。已经是此集成员的指定成员将被忽略。如果键不存在，则在添加指定成员之前创建一个新集。
An error is returned when the value stored at key is not a set.
如果键上存储的值不是集合，则返回错误。
1.1.2 返回
- 添加到集合中的元素数，不包括集合中已经存在的所有元素
1.1.3 练习
127.0.0.1:6379[1]> sadd myset a b c d e f g h i j k l m n
(integer) 14
1.2 scard
1.2.1 基本信息
SCARD key
summary: Get the number of members in a set
since: 1.0.0
Returns the set cardinality (number of elements) of the set stored at key.
返回存储在 key 处的集的元素数。
1.2.2 返回
- 集合的基数(元素数量) ，如果键不存在，则为0
1.2.3 练习
127.0.0.1:6379[1]> scard myset
(integer) 14
1.3 sdiff
1.3.1 基本信息
SDIFF key [key ...]
summary: Subtract multiple sets
since: 1.0.0
Returns the members of the set resulting from the difference between the first set and all the successive sets.
返回由第一个集和所有后续集之间的差集。
Keys that do not exist are considered to be empty sets.
不存在的键被认为是空集。
1.3.2 返回
- 包含结果集成员的列表
1.3.3 练习
127.0.0.1:6379[1]> sadd set2 a b d
(integer) 3
127.0.0.1:6379[1]> sadd set3 e f g
(integer) 3
127.0.0.1:6379[1]> sdiff myset set2 set3
1) "h"
2) "i"
3) "c"
4) "k"
5) "j"
6) "n"
7) "l"
8) "m"
1.4 sdiffstore
1.4.1 基本信息
SDIFFSTORE destination key [key ...]
summary: Subtract multiple sets and store the resulting set in a key
since: 1.0.0
This command is equal to SDIFF, but instead of returning the resulting set, it is stored in destination.
这个命令等于 SDIFF，但是不返回结果集，而是存储在目标中。
If destination already exists, it is overwritten.
如果目的地已经存在，则覆盖它。
1.4.2 返回
- 结果集中的元素数
1.4.3 练习
127.0.0.1:6379[1]> sdiffstore newset myset set2 set3
(integer) 8
1.5 sinter
1.5.1 基本信息
SINTER key [key ...]
summary: Intersect multiple sets
since: 1.0.0
Returns the members of the set resulting from the intersection of all the given sets.
返回由所有给定集的交集。
Keys that do not exist are considered to be empty sets. With one of the keys being an empty set, the resulting set is also empty (since set intersection with an empty set always results in an empty set).
不存在的键被认为是空集。如果其中一个键为空集，则结果集也为空(因为集与空集交集总是导致空集)。
1.5.2 返回
- 包含结果集成员的列表
1.5.3 练习
127.0.0.1:6379[1]> sinter myset set2 set3
(empty array)
1.6 sinterstore
1.6.1 基本信息
SINTERSTORE destination key [key ...]
summary: Intersect multiple sets and store the resulting set in a key
since: 1.0.0
This command is equal to SINTER, but instead of returning the resulting set, it is stored in destination.
该命令等于 SINTER，但是不返回结果集，而是存储在目标中。
If destination already exists, it is overwritten.
如果目的地已经存在，则覆盖它。
1.6.2 返回
- 结果集中的元素数
1.7 sismember
1.7.1 基本信息
SISMEMBER key member
summary: Determine if a given value is a member of a set
since: 1.0.0
Returns if member is a member of the set stored at key.
如果成员是按键存储的集的成员，则返回。
1.7.2 返回
- 如果元素是集合的成员，则为1。
- 如果元素不是集合的成员，或者键不存在，则返回0。
1.7.3 练习
127.0.0.1:6379[1]> sismember myset 1
(integer) 0
127.0.0.1:6379[1]> sismember myset a
(integer) 1
1.8 smembers
1.8.1 基本信息
SMEMBERS key
summary: Get all the members in a set
since: 1.0.0
Returns all the members of the set value stored at key.
返回按键存储的集值的所有成员。
1.8.2 返回
- 集合中的所有元素
1.8.3 练习
127.0.0.1:6379[1]> smembers set2
1) "d"
2) "b"
3) "a"
1.9 smismember
1.9.1 基本信息
SMISMEMBER key member [member ...]
summary: Returns the membership associated with the given elements for a set
since: 6.2.0
Returns whether each member is a member of the set stored at key.
返回每个成员是否是按键存储的集的成员。
For every member, 1 is returned if the value is a member of the set, or 0 if the element is not a member of the set or if key does not exist.
对于每个成员，如果值是集合的成员，则返回1; 如果元素不是集合的成员或键不存在，则返回0。
1.9.2 返回
- 表示给定元素的成员资格的列表，顺序与请求的顺序相同
1.9.3 练习
127.0.0.1:6379[1]> smismember set2 a c e f
1) (integer) 1
2) (integer) 0
3) (integer) 0
4) (integer) 0
1.10 smove
1.10.1 基本信息
SMOVE source destination member
summary: Move a member from one set to another
since: 1.0.0
Move member from the set at source to the set at destination. This operation is atomic. In every given moment the element will appear to be a member of source or destination for other clients.
将成员从源集移动到目标集。这次行动是原子级的。在每一个给定的时刻，元素看起来都是其他客户端的源或目标的成员。
If the source set does not exist or does not contain the specified element, no operation is performed and 0 is returned. Otherwise, the element is removed from the source set and added to the destination set. When the specified element already exists in the destination set, it is only removed from the source set.
如果源集不存在或不包含指定的元素，则不执行任何操作，并返回0。否则，元素将从源集中移除并添加到目标集中。当目标集中已经存在指定的元素时，只从源集中移除该元素。
An error is returned if source or destination does not hold a set value.
如果源或目标不包含设置值，则返回错误。
1.10.2 返回
- 如果元素被移动，则为1
- 如果元素不是源的成员并且未执行任何操作，则为0
1.10.3 练习
127.0.0.1:6379[1]> smove set2 set4 a
(integer) 1
1.11 spop
1.11.1 基本信息
SPOP key [count]
summary: Remove and return one or multiple random members from a set
since: 1.0.0
Removes and returns one or more random members from the set value store at key.
从键的设置值存储区中移除并返回一个或多个随机成员。
This operation is similar to SRANDMEMBER, that returns one or more random elements from a set but does not remove it.
这个操作类似于 SRANDMEMBER，它从一个集合中返回一个或多个随机元素，但不删除它。
By default, the command pops a single member from the set. When provided with the optional count argument, the reply will consist of up to count members, depending on the set's cardinality.
默认情况下，该命令从集合中弹出一个成员。当提供了可选的 count 参数时，根据集合的基数，应答将包含最多的 count 成员。
1.11.2 返回
- 当不使用 count 参数调用时，返回已删除的成员，或键不存在时为 nil
- 当使用 count 参数调用时，返回已删除的成员，或键不存在时为空数组
1.11.3 练习
127.0.0.1:6379[1]> spop set2
"b"
127.0.0.1:6379[1]> smembers set2
1) "d"
1.12 srandmember
1.12.1 基本信息
SRANDMEMBER key [count]
summary: Get one or multiple random members from a set
since: 1.0.0
When called with just the key argument, return a random element from the set value stored at key.
当仅使用 key 参数调用时，从存储在 key 上的 set 值返回一个随机元素。
If the provided count argument is positive, return an array of distinct elements. The array's length is either count or the set's cardinality (SCARD), whichever is lower.
如果提供的 count 参数为正，则返回一个包含不同元素的数组。数组的长度是 count 或集合的基数(SCARD) ，以较低者为准。
If called with a negative count, the behavior changes and the command is allowed to return the same element multiple times. In this case, the number of returned elements is the absolute value of the specified count.
如果调用时计数为负，则行为将发生更改，并允许命令多次返回相同的元素。在这种情况下，返回元素的数量是指定计数的绝对值。
1.12.2 返回
- 如果没有附加 count 参数，该命令将返回一个随机选择的元素，如果键不存在，则返回 nil
- 当传递额外的 count 参数时，命令返回一个元素数组，或者当键不存在时返回一个空数组
1.12.3 练习
127.0.0.1:6379[1]> srandmember set3
"f"
1.13 srem
1.13.1 基本信息
SREM key member [member ...]
summary: Remove one or more members from a set
since: 1.0.0
Remove the specified members from the set stored at key. Specified members that are not a member of this set are ignored. If key does not exist, it is treated as an empty set and this command returns 0.
从按键存储的集合中删除指定的成员。忽略不是此集成员的指定成员。如果 key 不存在，则将其视为空集，并且此命令返回0。
An error is returned when the value stored at key is not a set.
如果键上存储的值不是集合，则返回错误。
1.13.2 返回
- 从集中删除的成员数，不包括不存在的成员
1.13.3 练习
127.0.0.1:6379[1]> srem set3 f
(integer) 1
127.0.0.1:6379[1]> smembers set3
1) "e"
2) "g"
1.14 sscan
1.14.1 基本信息
SSCAN key cursor [MATCH pattern] [COUNT count]
summary: Incrementally iterate Set elements
since: 2.8.0
1.15 sunion
1.15.1 基本信息
SUNION key [key ...]
summary: Add multiple sets
since: 1.0.0
Returns the members of the set resulting from the union of all the given sets.
返回所有给定集合的并集
Keys that do not exist are considered to be empty sets.
不存在的键被认为是空集。
1.15.2 返回
- 包含结果集成员的列表
1.15.3 练习
127.0.0.1:6379[1]> sunion myset set2 set3
1) "h"
2) "i"
3) "c"
4) "f"
5) "k"
6) "j"
7) "e"
8) "n"
9) "g"
10) "b"
11) "d"
12) "a"
13) "l"
14) "m"
1.16 sunionstore
1.16.1 基本信息
SUNIONSTORE destination key [key ...]
summary: Add multiple sets and store the resulting set in a key
since: 1.0.0
This command is equal to SUNION, but instead of returning the resulting set, it is stored in destination.
这个命令等于 SUNION，但是不返回结果集，而是存储在目标中。
If destination already exists, it is overwritten.
如果目的地已经存在，则覆盖它。
1.16.2 返回
- 结果集中的元素数
1.16.3 练习
127.0.0.1:6379[1]> sunionstore newset set2 set3
(integer) 3
127.0.0.1:6379[1]> smembers newset
1) "e"
2) "d"
3) "g"