In PostgreSQL, the SUM() function computes the sum of the non-null input values and returns the result.
In other words, it adds numbers and returns the result.
With Oracle Database, we can use the TO_CHAR(datetime) function to return the century from a datetime value.
To do this, we can use either the CC format element, or the SCC format element. We can combine these with other format elements to do things like, display the ordinal number, spell out the century, etc.
In Oracle Database, there are a number of views that we can query to find out whether a table exists.
In PostgreSQL, the AVG() function computes the average (arithmetic mean) of all the non-null input values, and returns the result.
Some DBMSs such as Oracle, MySQL, and MariaDB have a DESCRIBE command that returns information about tables and views. It goes DESCRIBE table where table is the name of the table or view, and it can also be followed by a column name if you only want information about a specific column.
PostgreSQL doesn’t have a DESCRIBE TABLE command as such, but there are alternatives.
Here are three options for listing out all functions in a PostgreSQL database.
Here are three ways to get the data type of a given column in MariaDB.
Here are three ways to get information about a table’s columns in Oracle, including their data types.
In PostgreSQL, the MAX() function computes the maximum of the non-null input values and returns the result.
This function can be used on any numeric, string, date/time, or enum type, as well as inet, interval, money, oid, pg_lsn, tid, and arrays of any of these types.