I decided to compile a list of commands that can insert a new field into a Redis hash. Here are four options for inserting a new field into a Redis hash.
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Database Management Systems
Redis HINCRBYFLOAT Command
The Redis HINCRBYFLOAT command increments the field in the hash at the specified key by a floating point number. We specify how much we want the field to increment by when we call the command.
Redis HINCRBY Command
The Redis HINCRBY command increments the number that’s stored at the specified field in the hash at the specified key. We specify how much we want the field to increment by when we call the command.
Redis HVALS Command
The Redis HVALS command returns all values in the hash stored at the specified key.
Redis HLEN Command
The Redis HLEN command returns the number of fields in the hash stored at the specified key.
Fix “WRONGTYPE Operation against a key holding the wrong kind of value” when using SMEMBERS in Redis
If you get an error that reads “WRONGTYPE Operation against a key holding the wrong kind of value” when using the SMEMBERS command in Redis, it’s probably because you’re passing a key with the wrong data type to the command.
The SMEMBERS command is a “set” command, and so it is intended to be used on keys that contain a set. If the key holds a different data type, you’ll likely get the above error.
Redis HGETALL Command
The Redis HGETALL command returns all fields and values from the hash at the specified key.
Redis HMGET Command
The Redis HMGET command allows us to get multiple values from a hash. It returns the value/s associated with the specified field/s in the hash at the specified key.
Redis HGET Command
The Redis HGET command allows us to get a value from a hash. It returns the value associated with the specified field in the hash at the specified key.
3 Ways to Check if a Table has a Generated Column in SQLite
If you’re not sure if a table has a generated column in SQLite, you can quickly find out with either the .schema command, or by querying the sqlite_schema table.