Check out the following technique in MySQL if you need to find out how many days are in a month based on a given date.
Relational
JSON_INSERT() vs JSON_SET() vs JSON_REPLACE() in SQLite
SQLite provides several functions for inserting, setting, and replacing values in a JSON document. Specifically, it provides json_insert(), json_set(), and json_replace().
These functions perform similar tasks, and you can sometimes use them interchangeably to a certain point.
But there is definitely a clear difference between each function.
MySQL COALESCE() Explained
In MySQL, the COALESCE() operator returns the first non-NULL value in the list, or NULL if there are no non-NULL values.
Fix “At least one of the arguments to COALESCE must be an expression that is not the NULL constant” in SQL Server
In SQL Server, if you’re getting error Msg 4127 that reads “At least one of the arguments to COALESCE must be an expression that is not the NULL constant”, it’s probably because all of your arguments to the COALESCE() expression are the NULL constant.
To fix this issue, make sure at least one argument is not the NULL constant.
Detect Whether a Value Contains at Least One Numerical Digit in SQLite
The following SQLite example returns all rows that contain at least one numerical digit.
SQL Server COALESCE() Explained
In SQL Server, the COALESCE() expression returns its first non-null argument.
The way it works is, we pass a list of arguments to the expression, it evaluates the arguments in order and returns the current value of the first expression that initially doesn’t evaluate to NULL.
3 Ways to Extract a Value from a JSON Document in SQLite
When using SQLite, we can use the following methods to extract data from a JSON document.
How to Get the End of the Month in MariaDB
In MariaDB, we can use the LAST_DAY() function to return the last day of a given month.
This could be the last day of the current month, or the last day of the month based on a date that we specify.
Delete Duplicate Rows in MySQL (Ignores Primary Key)
The following example deletes duplicate rows in MySQL while ignoring the primary key or unique identifier column.
The example deletes duplicate rows but keeps one. So in the case of two identical rows, it deletes one of them and keeps the other.