Linuxteaching
Null
What is /dev/null and How to Use It
One such example is /dev/null. It's a special file that's present in every single Linux system. However, unlike most other virtual files, instead of r...
PostgreSQL IS NULL Query
Is null PostgreSQL query? Is Null Null in PostgreSQL? How do I allow null values in PostgreSQL? Is null in case statement PostgreSQL? What is null tim...
Use of default value of NULL in Django Model
The Django convention is to use the empty string, not NULL. The default values of null and blank are False. Also there is a special case, when you nee...
mysql if null
MySQL IFNULL() Function The IFNULL() function returns a specified value if the expression is NULL. If the expression is NOT NULL, this function return...
mysql if empty
Is Empty in MySQL query? Is null or is empty MySQL? How do I check if a SQL is not blank? How do I check if a variable is null in MySQL? What is the u...
How to use PHP Null Coalescing Operator
In PHP 7, a new feature, null coalescing operator (??) has been introduced. It is used to replace the ternary operation in conjunction with isset() fu...