PostgreSQL 18 reference · String Functions

PostgreSQL LEFT() Function

Return the first n characters of a string. A negative n returns all but the last |n| characters.

PostgreSQL 18 Since 9.1

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Syntax

left(string, n)

Parameter	Description
`string`	The input text.
`n`	How many characters to keep; negative drops from the end.

Text.

From the left

SELECT left('ReadyCamel', 5) AS a, left('ReadyCamel', -5) AS b;

Output

   a   |   b
-------+-------
 Ready | Ready
(1 row)

Run this on your computer — see “Get Started” for setup.

Initials

SELECT name, left(name, 1) || '.' AS initial
FROM customers
LIMIT 3;

Output

     name     | initial
--------------+---------
 Ada Lovelace | A.
 Alan Turing  | A.
 Grace Hopper | G.
(3 rows)

Run this on your computer — see “Get Started” for setup.

Version	Change
PostgreSQL 9.1	Added

RIGHT() · Return the last n characters of a string. A negative n returns all but the first |n| characters.
SUBSTRING() · Extract part of a string by 1-based position and length, or the part matching a regular expression.
SQL String Functions · tutorial