Postgresql LPAD() function

Syntax:

lpad(string,length[,fill_text])

Parameters:

Name	Description	Return Type
string	A string, which will be filled up by another string.	text
length	The length of the string, which will be after filled up by substring..	integer
fill_text	The substring which will be fill up the sting to length.	text

Pictorial Presentation of PostgreSQL LPAD() function

Code:

SELECT lpad('esource', 10, 'w3r');

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Sample Output:

    lpad
------------
 w3resource
(1 row)

Example 2:

In the example below, the main string is 'esource' and its length is 7, the substring is 'w3r' of length 3 and the string have to be a length of 13. So, remaining length is 6, and the substring 'w3r' will repeat two times to fill it up, thus the result is 'w3rw3resource'.

Code:

SELECT lpad('esource', 13, 'w3r');

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Sample Output:

    lpad
---------------
 w3rw3resource
(1 row)

Example 3:

In the example below, the main string is 'w3resource' and its length is 10, the substring is 'lpad' of length 4 and the string have to be a length of 8. Here, the specified length is smaller than the string, so, instead of lpadding the string will be truncated by two characters from the right side of the string, thus the result is 'w3resour'.

Code:

SELECT lpad('w3resource', 8, 'lpad');

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Sample Output:

  lpad
----------
 w3resour
(1 row)

출처 : https://w3resource.com/PostgreSQL/lpad-function.php