In Redis, the SMOVE
command moves a member of a set from one key to another. In other words, the member is removed from the source set and added to the destination set.
Fix: “ERR Number of keys can’t be greater than number of args” when using the SINTERCARD Command in Redis
If you’re getting an error that reads “ERR Number of keys can’t be greater than number of args” when using the SINTERCARD
command, it’s probably because your first argument is the wrong value.
To fix this issue, make sure the first argument reflects the number of sets that you’re comparing.
Continue readingRedis SMEMBERS Command Explained
In Redis, the SMEMBERS
command returns all members of a given set. We specify the key name of the set when we call the command.
Add a Virtual Column to an Existing Table in Oracle
If we need to add a virtual column to an existing table in Oracle Database, we can do so with the usual SQL ALTER TABLE
statement.
Redis SMISMEMBER Command Explained
In Redis, we can use the SMISMEMBER
command to find out whether one or more members are in a given set. It’s similar to the SISMEMBER
command, except that it allows us to check more than one member at a time.
The SMISMEMBER
command was introduced in Redis 6.2.0.
Redis SISMEMBER Command Explained
In Redis, we can use the SISMEMBER
command to find out whether or not a set contains a given member.
Fix “ERR wrong number of arguments for ‘sintercard’ command” in Redis
If you’re getting an error that reads “ERR wrong number of arguments for ‘sintercard’ command” in Redis, it’s because you’re calling the SINTERCARD
command with the wrong number of arguments.
To fix this issue, make sure you’re passing the correct number of arguments.
Continue readingRedis SINTERCARD Command Explained
In Redis, the SINTERCARD
command returns the cardinality of the set which would result from the intersection of all the given sets. It’s similar to SINTER
, but instead of returning the result set, it returns just the cardinality of the result.
The SINTERCARD
command was introduced in Redis 7.0.0.
How to Convert to Lowercase in MariaDB
In MariaDB, we can use the LOWER()
function to convert uppercase characters to their lowercase equivalent.
We can alternatively use LCASE()
, which is a synonym of LOWER()
.
Redis SINTERSTORE Command Explained
In Redis, the SINTERSTORE
command is the same as the SINTER
command, except that it stores the result in the specified key, instead of returning it.
It stores the members of the set resulting from the intersection of all the given sets.
If the destination key already exists, it’s overwritten. If it doesn’t exist, it’s created and the resulting members are added to it.
Continue reading