[redis] basic operation of key

• redis Common data type operation commands ：http://www.redis.cn/commands.html

1. Redis key (key)

1. keys *： View all of the current library keyundefined
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2. exists key： Judge a certain key Whether there is , There is no return 0
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3. type key ： see key What type is it
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4. del key： Delete specified key data
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5. unlink key： according to value Select non blocking delete , Only will keys from keyspace Delete from metadata , The real deletion will be done asynchronously later .
6. expire key 10：10 Second , For the specified key Set expiration time
7. ttl key ： See how many seconds are left to expire ,-1 Never expire ,-2 Indicates that it has expired
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8. select： Switch database
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9. dbsize： Returns the... Of the current database key The number of
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10. flushdb： Empty the current library
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11. flushall： Empty all libraries