In MariaDB, SUBTIME() is a built-in date and time function that subtracts an amount from a time or datetime expression.
It allows you to change a time or datetime expression by passing that expression, as well as a time expression to subtract from that expression. You can pass a negative amount if you need to add to the time expression.
Continue readingIn MariaDB, SUBDATE() is a built-in date and time function that subtracts an amount from a given date.
It allows you to change a date by specifying the date, the unit to subtract, and the amount to subtract. You can pass a negative amount in order to add to the date, instead of subtracting from it.
SUBDATE() also has a shortcut syntax that allows you to specify the days to subtract.
In MariaDB, DATE_SUB() is a built-in date and time function that allows you to subtract an amount from a date.
It allows you to change a date by specifying the date, the unit to subtract, and the amount to subtract. You can pass a negative amount in order to add to the date, instead of subtracting from it.
Continue readingIn MariaDB, ADDDATE() is a built-in date and time function that performs date arithmetic.
It allows you to change a date by specifying the date, the unit to add, and the amount to add. You can pass a negative amount if you need to subtract the date by a certain interval.
ADDDATE() also has a shortcut syntax that allows you to add a given number of days to the date.
In MariaDB, DATE_ADD() is a built-in date and time function that performs date arithmetic.
It allows you to change a date by specifying the date, the unit to add, and the amount to add. You can pass a negative amount if you need to subtract the date by a certain interval.
Continue readingThis article contains a list of date operators, methods, and variables that you can use when working with dates in MongoDB.
Continue readingI thought it would be interesting to run a few quick queries to see how various formatting strings affect the formatting of date/time values.
Below is a full list of date/time functions available in PostgreSQL.
Continue readingPostgres has the age() function that returns the age in years, months, and days based on two dates.
This works fine unless you only want to return the age in years.
For example, you simply want to return a person’s age based on their birthday. You want something like 32 instead of 32 years 4 mons 67 days, which is what age() is likely to return.
Fortunately there’s an easy way to do this in PostgreSQL.
Continue readingIn PostgreSQL you can use the extract() function to get the week number from a date.
You can also use the date_part() function to do the same thing.