142 lines
2.9 KiB
Markdown
142 lines
2.9 KiB
Markdown
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因收到Google相关通知，网站将会择期关闭。相关通知内容
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13 附录：更多集合操作命令
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移除并返回集合中的一个随机元素
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语法：spop key [count] 示例：
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127.0.0.1:6379> smembers myset
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1) "v1"
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2) "v2"
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127.0.0.1:6379> spop myset 1
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1) "v2"
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127.0.0.1:6379> smembers myset
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1) "v1"
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随机返回集合中指定数量的元素列表
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语法：srandmember key [count] 示例：
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127.0.0.1:6379> srandmember myset 2
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1) "v4"
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2) "v2"
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返回一个集合或多个集合的交集
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语法：sinter key [key …] 示例：
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127.0.0.1:6379> smembers myset
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1) "v1"
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2) "v3"
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3) "v2"
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127.0.0.1:6379> smembers myset2
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1) "v1"
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2) "v8"
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127.0.0.1:6379> sinter myset myset2
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1) "v1"
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把集合的交集复制到新的集合中
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语法：sinterstore destination key [key …] 示例：
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127.0.0.1:6379> smembers myset
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1) "v1"
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2) "v3"
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3) "v2"
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127.0.0.1:6379> smembers myset2
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1) "v1"
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2) "v8"
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127.0.0.1:6379> sinterstore myset3 myset myset2
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(integer) 1
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127.0.0.1:6379> smembers myset3
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1) "v1"
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命令解析：从以上代码可以看出，我们把集合 myset 和 集合 myset2 的合集元素 v1 复制到了新的集合 myset3 中，但 v1 并不会从原有集合中移除。
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查询一个或多个集合的并集
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语法：sunion key [key …] 示例：
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127.0.0.1:6379> smembers group1
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1) "java"
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127.0.0.1:6379> smembers group2
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1) "golang"
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127.0.0.1:6379> sunion group1 group2
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1) "java"
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2) "golang"
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把一个或多个集合的并集复制到新集合中
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语法：sunionstore destination key [key …] 示例：
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127.0.0.1:6379> smembers group1
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1) "java"
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127.0.0.1:6379> smembers group2
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1) "golang"
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127.0.0.1:6379> sunionstore group3 group1 group2
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(integer) 2
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127.0.0.1:6379> smembers group3
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1) "java"
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2) "golang"
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注意：只是把一个或多个集合的并集复制到新集合中，并不会在原集合中删除复制的元素。
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查询一个或多个集合的错集
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语法：sdiff key [key …] 示例：
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127.0.0.1:6379> smembers group1
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1) "java"
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2) "golang"
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127.0.0.1:6379> smembers group2
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1) "golang"
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127.0.0.1:6379> sdiff group1 group2
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1) "java"
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注意：执行命令时集合的先后顺序会影响返回的结果，如下所示：
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127.0.0.1:6379> sdiff group1 group2
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1) "java"
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127.0.0.1:6379> sdiff group2 group1
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(empty list or set)
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这是因为查询错集是以第一个集合为主的，当第二个元素包含第一个元素时，查询的错集结果就是空。
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把一个或多个集合的错集复制到新集合
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语法：sdiffstore destination key [key …] 示例：
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127.0.0.1:6379> smembers group1
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1) "java"
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2) "golang"
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127.0.0.1:6379> smembers group2
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1) "golang"
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127.0.0.1:6379> sdiffstore group3 group1 group2
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(integer) 1
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127.0.0.1:6379> smembers group3
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1) "java"
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