In MariaDB, the JSON_VALUE() function and JSON_QUERY() function do similar things – they return data from a JSON document.
So what’s the difference?
The main difference is that JSON_VALUE() returns scalar values, whereas JSON_QUERY() returns arrays and objects.
In Oracle Database, the FROM_TZ() function converts a timestamp value and a time zone to a TIMESTAMP WITH TIME ZONE value.
You pass the timestamp value and the time zone as two separate arguments, and the function returns them as a TIMESTAMP WITH TIME ZONE value.
Sometimes we need to specify a time zone when using datetime functions in Oracle.
But there are a lot of time zones out there. How do we remember them all? And how do we know our system supports a given time zone?
Fortunately, we can query the V$TIMEZONE_NAMES view to return a list of valid time zones.
In Oracle Database, the SESSIONTIMEZONE function returns the time zone of the current session.
In Oracle Database, the DBTIMEZONE function returns the value of the database time zone.
When working with functions that return dates, Oracle Database returns these dates based on the value of the NLS_DATE_FORMAT parameter.
There is also an NLS_TIMESTAMP_FORMAT parameter and an NLS_TIMESTAMP_TZ_FORMAT parameter, both of which have a datetime format mask that can be specified separately.
All of these parameters have their default values derived from the NLS_TERRITORY parameter (which by default, is operating system-dependent).
In Oracle Database, the NLS (National Language Support) parameters determine the locale-specific behaviour on both the client and the server.
These parameters can be set in various places, such as at the database level, in an initialization parameter file, in environment variables, at the session level, and even within some functions.
You can check the value of the NLS parameters with the following views.
In Oracle Database, the ADD_MONTHS() function adds a given number of months to a date, and returns the result.
Oracle Database includes a bunch of NLS (National Language Support) parameters that determine the locale-specific behaviour on both the client and the server.
These NLS parameters can be set in various places, each of which has a predetermined precedence order in relation to the others. The following table outlines these methods, as well as their priority in relation to the others.
In Oracle Database, the NLS_LANGUAGEÂ initialization parameter specifies the default language of the database.
This language is used for messages, day and month names, symbols for AD, BC, a.m., and p.m., and the default sorting mechanism.
The NLS_LANGUAGEÂ parameter also determines the default values of the NLS_DATE_LANGUAGE and NLS_SORT parameters.
This article outlines how to change the value of the NLS_LANGUAGEÂ and NLS_DATE_LANGUAGEÂ parameters.