If you’re getting an error that reads “ERR syntax error” when using the HRANDFIELD command in Redis, it could be that you’re passing the wrong number of arguments. At the time of writing, the HRANDFIELD command requires at least one argument, and accepts up to three arguments.
Author: Ian
5 Ways to Check if a Field Exists in a Redis Hash
Redis provides some easy ways to check whether or not a field exists in a given hash. Here are five commands that we can use to check for the existence of a field in a given hash.
Continue readingPostgreSQL DATE_BIN() Function Explained
In PostgreSQL, the DATE_BIN() function enables us to “bin” a timestamp into a given interval aligned with a specific origin. In other words, we can use this function to map (or force) a timestamp to the nearest specified interval.
This can be handy when we want to truncate a timestamp to a given interval, for example a 10 minute interval. We can specify the interval (e.g. 10 minutes, 15 minutes, 30 minutes, etc), and we can specify the starting point for the interval. Therefore, we can have the interval starting at any odd time we want (it doesn’t need to start on the hour or anything like that).
Continue reading3 Ways to Update a Field in a Redis Hash
The following commands can be used to update a field in a Redis hash. The command we use will depend on the type of data that’s stored in the field.
Continue readingHow to Return Field Values when using HRANDFIELD in Redis
In Redis, we can use the HRANDFIELD command to return random fields from a given hash. By default, only the field names are returned.
But what if we want to include the field values?
In this case, we can use the WITHVALUES option when calling the command.
4 Ways to Clone a Table in MySQL
MySQL provides us with several ways to copy a database table. The method we use will depend on our requirements.
We can choose to copy the table, its data, and its indexes. Or we can copy just the table and data without the indexes. We can alternatively generate the code that will enable us to copy the table later.
Continue readingFix: “ERR wrong number of arguments for ‘smove’ command” in Redis
If you’re getting an error that reads “ERR wrong number of arguments for ‘smove’ command” in Redis, it’s because you’re calling the SMOVE command with the wrong number of arguments.
To fix this issue, make sure you’re passing the correct number of arguments. At the time of writing, the correct number of arguments for this command is three.
Continue readingHow to Delete a Field in a Redis Hash
If you’ve got a Redis hash with a field that needs to be deleted, you can use the HDEL command.
Fix “ERR syntax error” when calling SRANDMEMBER in Redis
If you’re getting an error that reads “ERR syntax error” when calling the SRANDMEMBER command in Redis, it could be that you’re passing too many arguments.
To fix this issue, be sure to pass the correct number of arguments. At the time of writing, SRANDMEMBER accepts up to two arguments. Any more than this results in an error.
4 Ways to Insert a Field in a Redis Hash
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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