To clear the contents of a key in Redis, you need to first determine the data type of the key. Different data types have different operation methods in Redis. If you just want to delete the key and its associated value, you can use DELthe command.
Here is the basic delete operation:
DEL keyname
where keynameis the name of the key you want to delete. After executing this command, the key and its associated value will be deleted.
If your key is a list, set, or hash table, and you just want to clear the value associated with the key but keep the key, then you need to perform different operations depending on the specific data type. For example, if your key is a list, you can use LTRIMthe command to empty the list:
LTRIM keyname 1 0
This will keep the keys, but empty the associated list.
If your key is a set, you can SMEMBERSget all the members with the command, and SREMdelete them one by one with the command.
If your key is a hash table, you can HKEYSget all the fields with the command, and then HDELdelete them one by one with the command.
Note that the above operations are only applicable when you need to clear but not delete. If you just want to delete the key, then using DELthe command is enough.