> This page location: String Functions > TRIM > Full Neon documentation index: https://neon.com/docs/llms.txt # PostgreSQL TRIM() Function **Summary**: in this tutorial, you will learn how to use the PostgreSQL `TRIM()` function to remove specified prefixes or suffixes (or both) from a string. ## Introduction to PostgreSQL TRIM() function The `TRIM()` function allows you to remove specified prefixes or suffixes (or both) from a string. Here's the basic syntax of the `TRIM()` function: ```sql TRIM([LEADING | TRAILING | BOTH] trim_character FROM source_string) ``` In this syntax: - `source_string`: Specify the string that you want to remove specified characters. - `trim_character`: Specify the trim characters. - `LEADING`: This option instructs the function to remove the leading occurrences of the specified trim character. - `TRAILING`: This option instructs the function to remove trailing occurrences of the specified trim character. - `BOTH`: This option instructs the function to remove both leading and trailing occurrences of the specified trim character. The `TRIM()` function can be very useful when you want to clean up strings. To remove specific characters from the beginning of a string, you use the [LTRIM()](https://neon.com/postgresql/postgresql-string-functions/postgresql-ltrim) function. To remove specific characters from the end of a string, you can use the [RTRIM()](https://neon.com/postgresql/postgresql-string-functions/postgresql-rtrim) function. ## PostgreSQL TRIM() function examples Let's explore some examples of using the `TRIM()` function. ### 1) Basic PostgreSQL TRIM() function example The following example uses the `TRIM()` function to remove leading and trailing spaces from the string `' PostgreSQL '`: ```sql SELECT TRIM(' PostgreSQL ') AS trimmed_string; ``` Output: ``` trimmed_string ---------------- PostgreSQL (1 row) ``` The output is a string without leading and trailing spaces. ### 2) Using the PostgreSQL TRIM() function to remove specific characters The following example uses the `TRIM()` function to remove leading and trailing hash symbols (`#`) from the string `'##PostgreSQL##'`: ```sql SELECT TRIM('#' FROM '##PostgreSQL##') AS trimmed_string; ``` Output: ``` trimmed_string ---------------- PostgreSQL (1 row) ``` ### 3) Using the TRIM() function to remove specific characters by specifying the trim location The following example uses the PostgreSQL `TRIM()` function to remove leading, trailing, and both leading and trailing zeros from the string `'0000123450'`: ```sql SELECT TRIM(LEADING '0' FROM '000123450') AS trimmed_string_leading, TRIM(TRAILING '0' FROM '000123450') AS trimmed_string_trailing, TRIM(BOTH '0' FROM '000123450') AS trimmed_string_both; ``` Output: ``` trimmed_string_leading | trimmed_string_trailing | trimmed_string_both ------------------------+-------------------------+--------------------- 123450 | 00012345 | 12345 (1 row) ``` ### 4) Using the TRIM() function with table data First, [create a table](../postgresql-tutorial/postgresql-create-table) called `todo` and [insert](../postgresql-tutorial/postgresql-insert) some sample data: ```sql CREATE TABLE todo( id SERIAL PRIMARY KEY, title VARCHAR(255) NOT NULL, completed BOOL NOT NULL DEFAULT false ); INSERT INTO todo(title) VALUES (' Learn PostgreSQL '), ('Build an App ') RETURNING *; ``` Output: ``` id | title | completed ----+------------------------+----------- 1 | Learn PostgreSQL | f 2 | Build an App | f (2 rows) ``` Second, remove the leading and trailing spaces from the `title` column using the `TRIM()` function: ```sql UPDATE todo SET title = TRIM(title); ``` Output: ``` UPDATE 2 ``` Third, verify the updates: ```sql SELECT * FROM todo; ``` Output: ``` id | title | completed ----+------------------+----------- 1 | Learn PostgreSQL | f 2 | Build an App | f (2 rows) ``` ## Summary - Use the PostgreSQL `TRIM()` function to remove a specified leading, trailing, or both leading and trailing characters from a string. --- ## Related docs (String Functions) - [ASCII](https://neon.com/postgresql/postgresql-string-functions/postgresql-ascii) - [CHR](https://neon.com/postgresql/postgresql-string-functions/postgresql-chr) - [CONCAT](https://neon.com/postgresql/postgresql-string-functions/postgresql-concat-function) - [CONCAT_WS](https://neon.com/postgresql/postgresql-string-functions/postgresql-concat_ws) - [FORMAT](https://neon.com/postgresql/postgresql-string-functions/postgresql-format) - [INITCAP](https://neon.com/postgresql/postgresql-string-functions/postgresql-initcap) - [LEFT](https://neon.com/postgresql/postgresql-string-functions/postgresql-left) - [LENGTH](https://neon.com/postgresql/postgresql-string-functions/postgresql-length-function) - [LOWER](https://neon.com/postgresql/postgresql-string-functions/postgresql-lower) - [LPAD](https://neon.com/postgresql/postgresql-string-functions/postgresql-lpad) - [LTRIM](https://neon.com/postgresql/postgresql-string-functions/postgresql-ltrim) - [MD5](https://neon.com/postgresql/postgresql-string-functions/postgresql-md5) - [POSITION](https://neon.com/postgresql/postgresql-string-functions/postgresql-position) - [REGEXP_MATCHES](https://neon.com/postgresql/postgresql-string-functions/postgresql-regexp_matches) - [REGEXP_REPLACE](https://neon.com/postgresql/postgresql-string-functions/regexp_replace) - [REPEAT](https://neon.com/postgresql/postgresql-string-functions/postgresql-repeat) - [REVERSE](https://neon.com/postgresql/postgresql-string-functions/postgresql-reverse) - [REPLACE](https://neon.com/postgresql/postgresql-string-functions/postgresql-replace) - [RIGHT](https://neon.com/postgresql/postgresql-string-functions/postgresql-right) - [RPAD](https://neon.com/postgresql/postgresql-string-functions/postgresql-rpad) - [RTRIM](https://neon.com/postgresql/postgresql-string-functions/postgresql-rtrim) - [SPLIT_PART](https://neon.com/postgresql/postgresql-string-functions/postgresql-split_part) - [SUBSTRING](https://neon.com/postgresql/postgresql-string-functions/postgresql-substring) - [TO_CHAR](https://neon.com/postgresql/postgresql-string-functions/postgresql-to_char) - [TO_NUMBER](https://neon.com/postgresql/postgresql-string-functions/postgresql-to_number) - [TRANSLATE](https://neon.com/postgresql/postgresql-string-functions/postgresql-translate) - [UPPER](https://neon.com/postgresql/postgresql-string-functions/postgresql-upper)