Database Management Systems
In MariaDB, the CASE statement can be used in stored programs to perform a complex conditional construct. It compares a list of conditions and returns a different result depending on which condition (if any) is matched.
The CASE statement is distinct from the CASE operator, in that the CASE statement is specifically for use in stored programs. Also, there’s a slight difference in the syntax.
In Redis, the DECRBY command decrements the value of a key by the specified amount.
If the key doesn’t exist, DECRBY creates the key with a value of 0 and then decrements it by the specified amount.
An error occurs if the key contains a value of the wrong type or contains a string that cannot be represented as integer. DECRBY operations are limited to 64 bit signed integers.
In Redis, the DECR command decrements the value of a specified key by one.
If the key doesn’t exist, DECR creates the key with a value of 0 and then decrements it by one.
An error occurs if the key contains a value of the wrong type or contains a string that cannot be represented as integer.
Continue readingIn Redis, the INCRBYFLOAT command increments a floating point number by the specified amount. More specifically, it increments the string representing a floating point number stored at the specified key.
If the key doesn’t exist, INCRBYFLOAT creates the key with a value of 0 and then increments it by the specified amount.
An error occurs if the key contains a value of the wrong type, or if the current key content or the specified increment are not parsable as a double precision floating point number.
Continue readingWhen we have a table with a generated column, here are two methods we can use to return its definition.
Continue readingIn Redis, the INCRBY command increments the value of a key by the specified amount.
If the key doesn’t exist, INCRBY creates the key with a value of 0 and then increments it by the specified amount.
An error occurs if the key contains a value of the wrong type or contains a string that cannot be represented as integer. INCRBY operations are limited to 64 bit signed integers.
In Redis, the INCR command increments the value of a specified key by one.
If the key doesn’t exist, INCR creates the key with a value of 0 and then increments it by one.
An error occurs if the key contains a value of the wrong type or contains a string that cannot be represented as integer.
Continue readingThe Redis PERSIST command removes any existing timeout on a given key. It returns an integer reply of 1 if the timeout was removed, or 0 if the key doesn’t exist or doesn’t have an associated timeout.
In Redis, the PTTL command returns the remaining time to live of a given key, in milliseconds.
If the key doesn’t have a timeout, an integer reply of -1 is returned. If the key doesn’t exist, -2 is returned.
PTTL works the same as the TTL command, except that it returns the result in milliseconds instead of seconds.
In Redis, the TTL command returns the remaining time to live of a given key, in seconds.
If the key doesn’t have a timeout, an integer reply of -1 is returned. If the key doesn’t exist, -2 is returned.
Redis also has a PTTL command, which works the same, but returns its result in milliseconds.