The Redis GETEX
command enables us to get the value of a key, then set the key’s expiration. We can also use it to remove any existing expiration associated with the key.
Author: Ian
How NVL2() Works in MariaDB
In MariaDB, the NVL2()
function allows us to replace a value with another value, the new value being determined by whether or not the initial value is null.
It’s similar to the NVL()
function, except that NVL2()
accepts three arguments instead of two. This allows us to specify a different value to return in the event the first argument is not null.
2 Ways to Check your Redis Client Version
Here are two quick and easy options to find out what version of the Redis client (redis-cli
) you’re using.
4 Ways to Check your Redis Version
Here are four quick and easy ways to find out what version of Redis you’re using.
Continue readingRedis SETNX Command Explained
The Redis SETNX
command sets a key to a given value, but only if the key doesn’t already exist. If the key already holds a value, no operation is performed.
Note: The SET
command can do the same thing, and it’s possible that the SETNX
command may be deprecated at some point. Therefore, it’s probably a good idea to use SET
instead of SETNX
if possible.
How to Get the Last Day of the Month in SQL
Below are examples of using SQL to return the last day of the month across various DBMSs.
This could be the last day of the current month, or the last day of a month based on a given date.
Continue readingRedis MSETNX Command Explained
In Redis, the MSETNX
command allows us to set multiple keys at once, but only if none of them exist.
This allows us to set multiple keys representing different fields of a single logical object in a way that ensures that either all the fields are set, or none are set.
Continue readingRedis MGET Command Explained
In Redis, the MGET
command allows us to get the values of multiple keys at once. The values are returned in an array reply.
If a specified key doesn’t exist, MGET
returns nil
for that key.
Redis MSET Command Explained
In Redis, the MSET
command allows us to set multiple keys at once. It replaces any existing values, just as SET
does.
SQL Server CASE Statement
The SQL Server CASE
statement evaluates a list of conditions and returns one of multiple possible result expressions.
Although it’s commonly known as the “CASE
statement”, the SQL Server documentation lists it as an expression. Plus it’s referred to as the “CASE
expression” in the SQL standard. Some other DBMSs distinguish between the CASE
statement and the CASE
expression. Either way, here’s a quick rundown on how the “CASE
statement” (or CASE
expression) works in SQL Server.