Database Management Systems
MariaDB has quite a number of functions that return the day from a date. It all depends on how you want to do it, and what you mean by “day”.
MariaDB needs to know whether you want the day name, the day of the week number, the day of the month, day of year, etc.
Below are 8 functions that enable you to return the day from a date in MariaDB, in its various forms.
Continue readingIn Oracle, the BITAND() function returns a bitwise AND of its two arguments.
SQLcl and SQL*Plus are command line interfaces for working with Oracle Database.
By default, they return an empty string whenever null occurs as a result of a SQL SELECT statement.
However, you can use SET NULL to specify a different string to be returned. Here I specified that the string null should be returned.
Starting with SQLcl version 21.2, we can now configure SQLcl for syntax highlighting.
That means that the code you write in SQLcl can be color coded, based on the syntax highlighting rules you apply.
Continue readingWhen using SQLcl (Oracle’s command line interface), you can create a login.sql file, and have it run each time you run SQLcl.
This allows you to have commands executed each time you run SQLcl. For example, you can specify your formatting preferences in the login.sql file, set up aliases, etc.
Here I show you how to create a login.sql file and how to make it run each time you run SQLcl.
In Oracle, the ASIN() function returns the arcsine (inverse sine) of its argument.
In other words, it returns the value whose sine is the argument.
Continue readingWhen you run a query against an Oracle database using SQLcl or SQL*Plus, the results are displayed according to the SQLFORMAT option. But within that, there are other things you can do to customise the format of the results.
One of the things you can do is specify a column separator for the output grid.
Continue readingIn MariaDB, JSON_VALID() is a built-in function that allows you to check whether or not a value is a valid JSON document.
You pass the value as an argument, and JSON_VALID() returns 1 if it’s a valid JSON document, and 0 if not.
In Oracle, the ACOS() function returns the arccosine (inverse cosine) of its argument.
In other words, it returns the value whose cosine is the argument.
Continue readingIn Oracle, the ABS() function returns the absolute value of its argument.
The absolute value is the non-negative value of a real number without regard to its sign. It describes the distance from zero that a number is on the number line, without considering direction.
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