If you get an error that reads “WRONGTYPE Operation against a key holding the wrong kind of value” when setting a hash with a command like HSET or HSETNX, it’s probably because you’re trying to set a non-hash key that already exists. In other words, the key already exists, but it doesn’t contain a hash.
To fix this issue, be sure to use these commands on keys that either don’t already exist, or contain a hash.
Continue readingIf you’re getting error 1045 that reads something like “Access denied for user ‘root’@’localhost’“, it’s because you’re trying to log in to MySQL without the right credentials.
This usually happens when we provide the wrong password. But there could also be another cause. For example, we could be trying to do something as the root user that requires a password, but the root user hasn’t yet had its password set.
To fix this issue, be sure to provide the correct password when connecting to MySQL.
Continue readingIf you’re getting an error that reads “ERR wrong number of arguments for ‘srandmember’ command” in Redis, it’s probably because you’re calling the SRANDMEMBER command without any arguments.
To fix this issue, make sure you pass the correct number of arguments. At the time of writing, the SRANDMEMBER command requires at least one argument, and accepts an optional second argument.
If you get an error that reads “WRONGTYPE Operation against a key holding the wrong kind of value” when using the ZINTER command in Redis, it’s probably because you’re passing a key with the wrong data type.
To fix this issue, be sure that each key you pass to the ZINTER command is either a set or a sorted set.
If you’re getting an error that reads “ERR wrong number of arguments for ‘smismember’ command” in Redis, it’s because you’re calling the SMISMEMBER command with the wrong number of arguments.
To fix this issue, make sure you’re passing the correct number of arguments. This command accepts two or more arguments, which represents a key and one or more members to check against that key.
Continue readingIf you’re getting an error that reads “NEXT VALUE FOR function does not support the PARTITION BY clause” in SQL Server, it’s probably because you’re trying to use the PARTITION BY sub clause in an OVER clause when using NEXT VALUE FOR to increment a sequence object.
In other words, the NEXT VALUE FOR function does not support the PARTITION BY sub clause of the OVER clause.
To fix this issue, either remove the PARTITION BY clause or change the statement to use another method for partitioning the results.
If you get an error that reads “WRONGTYPE Operation against a key holding the wrong kind of value” when using the ZUNION or ZUNIONSTORE commands in Redis, it’s because you’re passing a key with the wrong data type.
To fix this issue, make sure the keys you pass to these commands contain either sets or sorted sets. Although these commands are for sorted sets, they also work with non-sorted sets.
Continue readingIf you get an error that reads “WRONGTYPE Operation against a key holding the wrong kind of value” when using the LRANGE command, it’s probably because you’re passing a key with the wrong data type.
To fix this issue, be sure that the key you pass to the LRANGE command holds a list.
If you’re getting an error that reads something like “ERROR 1050 (42S01): Table ‘customers’ already exists” when trying to create a table in MySQL, it’s probably because there’s already a table in the database with the same name.
To fix this issue, either change the name of the table you’re trying to create, or check the existing table to see if it’s the one you actually need.
Continue readingIf you’re getting an error that reads “ERR value is not an integer or out of range” when using the HRANDFIELD command in Redis, it could be because you’re passing a second argument that isn’t an integer. Or if it is an integer, it could be out of range.