In PostgreSQL, the GREATEST() function returns the greatest (or largest) value from a list of any number of expressions.
The GREATEST() function is not included in the SQL standard, but it’s a popular extension that many major RDBMSs support.
Tag: psql
LEAST() Function in PostgreSQL
In PostgreSQL, the LEAST() function returns the smallest value from a list of any number of expressions.
The LEAST() function is not included in the SQL standard, but it’s a popular extension that many major RDBMSs support.
How to Convert a Unix Timestamp to a Date/Time Value in PostgreSQL
In PostgreSQL, we can use the to_timestamp() function to convert a Unix timestamp value to a date/time value.
The Unix timestamp (also known as Unix Epoch time, Unix time, or POSIX time) is the number of seconds that have elapsed since 00:00:00 Thursday, 1 January 1970, Coordinated Universal Time (UTC).
Continue readingSubtract Weeks from a Date in PostgreSQL
We can use the - operator to subtract one or more weeks from a date in PostgreSQL.
Get the Last Day of the Month in PostgreSQL
We can use the following technique in PostgreSQL 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.
Continue readingSubtract Months from a Date in PostgreSQL
In PostgreSQL, we can use the - operator to subtract one or more months from a date.
Return the Unix Timestamp in PostgreSQL
In PostgreSQL, we can use the extract() function along with the epoch argument to return the Unix timestamp.
We can return the Unix timestamp based on the current date/time, or we can get it based on another specified date/time.
Continue readingSubtract Minutes from a Time Value in PostgreSQL
In PostgreSQL, we can use the - operator to subtract one or more minutes from a time value.
By “time” value, this could be an actual time value, a timestamp, or an interval. We can also subtract minutes from a date value or a date and time combination.
Get the Number of Days in a Month in PostgreSQL
Here’s an example of using PostgreSQL to return the number of days in a month, based on a given date.
Continue readingUPPER() – Convert to Uppercase in PostgreSQL
In PostgreSQL, we can use the upper() function to convert lowercase characters to their uppercase equivalent, according to the rules of the database’s locale.