string type:
- Add and modify data
mset key1 value1 key2 value2 [.....]
- retrieve data
mget key1 key2 key3[....]
- Get character size
strlen key
- Append information to the back of the original information
append key value
- Set the data to increase the value of the specified range
incr key
incrby key increment
incrbyfloat key increment
- Set the data value to reduce the value of the specified range
decr key
decrby key incrment
Extended operations on String data
Set the data to have a specified life cycle
powershell setex key seconds value
powershell psetex key milliseconds value
