In Redis, we have several options for returning the expiry time of a key. One option from Redis 7.0.0 and above is to return it as a Unix timestamp.
When returning the expiry as a Unix timestamp, we can have it returned in seconds or milliseconds. To return it in seconds, we can use the EXPIRETIME command. To return it in milliseconds, we can use the PEXPIRETIME command.
In Redis, it’s possible to set a key only if it doesn’t already exist. As with most things, there’s more than one way to do this.
In Redis, the SCARD command returns the number of members in the specified set. This is referred to as the cardinality of the set.
In Redis, the SADD command allows us to add members to a key. We can add multiple members if required.
A Redis set is an unordered collection of unique strings (members).
When working with Redis, we have a number of options for setting keys that store string values.
Here are six ways to set a string value in Redis.
A Redis key can have an optional timeout, which makes the key expire after a certain amount of time, or at a certain time. We can use a couple of methods to remove any timeout associated with a key.
Here are two ways to remove a key’s expiry in Redis.
When using the SET command to set a key in Redis, we can use the GET option to return its old value. This allows us to update the value of a key while returning the value that we’re replacing it with.
Note that this option was introduced in Redis 7.0.0, so if it doesn’t work, check your Redis version. If using an earlier version, try the GETSET command instead (which is deprecated from Redis version 6.2.0).
In SQLite, we can use the DATE() function to subtract one or more months from a date.
For datetime values, we can use the DATETIME() function.