LPAD and RPAD Functions
These functions prepend or append characters to a string, based on a specified length.
LPAD (string1, length, [ string2 ])
RPAD (string1, length, [ string2 ])
A character string or an expression that evaluates to a character string, such as the name of a character column.
An integer that defines the length of the result of the function. The length of a string is based on the number of characters, not bytes, so that multi-byte characters are counted as single characters. If string1 is longer than the specified length, it is truncated (on the right). If length is a negative number, the result of the function is an empty string.
One or more characters that are prepended or appended to string1. This argument is optional; if it is not specified, spaces are used.
These functions return a VARCHAR data type.
Truncate a specified set of event names to 20 characters and prepend the shorter names with spaces:
select lpad(eventname,20) from event where eventid between 1 and 5 order by 1; lpad ---------------------- Salome Il Trovatore Boris Godunov Gotterdammerung La Cenerentola (Cind (5 rows)
Truncate the same set of event names to 20 characters but append the shorter names
select rpad(eventname,20,'0123456789') from event where eventid between 1 and 5 order by 1; rpad ---------------------- Boris Godunov0123456 Gotterdammerung01234 Il Trovatore01234567 La Cenerentola (Cind Salome01234567890123 (5 rows)