> This page location: String Functions > CONCAT > Full Neon documentation index: https://neon.com/docs/llms.txt # PostgreSQL CONCAT() Function **Summary**: in this tutorial, you will learn how to use the PostgreSQL `CONCAT()` function to concatenate two or more strings into one. ## Introduction to PostgreSQL CONCAT() function To concatenate two or more strings into a single string, you can use the string concatenation operator || as shown in the following example: ```sql SELECT 'John' || ' ' || 'Doe' AS full_name; ``` Output: ```text full_name ----------- John Doe (1 row) ``` The following statement uses the concatenation operator (`||`) to concatenate a string with `NULL`: ```sql SELECT 'John' || NULL result; ``` It returns `NULL`. ```text result -------- null (1 row) ``` Since version 9.1, PostgreSQL has introduced a built-in string function called `CONCAT()` to concatenate two or more strings into one. Here's the basic syntax of the `CONCAT()` function: ```sql CONCAT(string1, string2, ...) ``` The `CONCAT` function accepts a list of input strings, which can be any string type including `CHAR`, `VARCHAR`, and `TEXT`. The `CONCAT()` function returns a new string that results from concatenating the input strings. Unlike the concatenation operator `||`, the `CONCAT` function ignores `NULL` arguments. To concatenate two or more strings into one using a specified separator, you can use the [CONCAT_WS()](https://neon.com/postgresql/postgresql-string-functions/postgresql-concat_ws) function. ## PostgreSQL CONCAT() function examples Let's take some examples of using the PostgreSQL `CONCAT()` function. ### 1) Basic PostgreSQL CONCAT() function example The following example uses the `CONCAT()` function to concatenate three literal strings into one: ```sql SELECT CONCAT ('John', ' ', 'Doe') full_name; ``` Output: ```text full_name ----------- John Doe (1 row) ``` ### 2) Using the CONCAT() function with table data example We'll use the `customer` table from the [sample database](https://neon.com/postgresql/postgresql-getting-started/postgresql-sample-database): ![customer table](https://neon.com/postgresqltutorial/customer.png)The following statement uses the `CONCAT()` function to concatenate values in the `first_name`, a space, and values in the `last_name` columns of the `customer` table into a single string: ```sql SELECT CONCAT (first_name, ' ', last_name) AS full_name FROM customer ORDER BY full_name; ``` Output: ```text full_name ----------------------- Aaron Selby Adam Gooch Adrian Clary Agnes Bishop Alan Kahn ... ``` ### 3) Using the CONCAT() function with NULL First, [create a table](../postgresql-tutorial/postgresql-create-table) called `contacts` and [insert some rows](../postgresql-tutorial/postgresql-insert-multiple-rows) into it: ```sql CREATE TABLE contacts ( id SERIAL PRIMARY KEY, name VARCHAR(255) NOT NULL, email VARCHAR(255) NOT NULL, phone VARCHAR(15) ); INSERT INTO contacts (name, email, phone) VALUES ('John Doe', 'john.doe@example.com', '123-456-7890'), ('Jane Smith', 'jane.smith@example.com', NULL), ('Bob Johnson', 'bob.johnson@example.com', '555-1234'), ('Alice Brown', 'alice.brown@example.com', NULL), ('Charlie Davis', 'charlie.davis@example.com', '987-654-3210') RETURNING *; ``` Output: ```text id | name | email | phone ----+---------------+---------------------+-------------- 1 | John Doe | john.doe@example.com | 123-456-7890 2 | Jane Smith | jane.smith@example.com | null 3 | Bob Johnson | bob.johnson@example.com | 555-1234 4 | Alice Brown | alice.brown@example.com | null 5 | Charlie Davis | charlie.davis@example.com | 987-654-3210 (5 rows) INSERT 0 5 ``` Second, use the `CONCAT()` function to concatenate the values in the `name`, `email`, and `phone` columns of the `contacts` table: ```sql SELECT CONCAT(name, ' ', '(', email, ')', ' ', phone) contact FROM contacts; ``` Output: ``` contact -------------------------------------------------- John Doe (john.doe@example.com) 123-456-7890 Jane Smith (jane.smith@example.com) Bob Johnson (bob.johnson@example.com) 555-1234 Alice Brown (alice.brown@example.com) Charlie Davis (charlie.davis@example.com) 987-654-3210 (5 rows) ``` The output indicates that the `CONCAT()` function ignores `NULL`. ## Summary - Use the PostgreSQL `CONCAT()` function to concatenate two or more strings into one. --- ## 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_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) - [TRIM](https://neon.com/postgresql/postgresql-string-functions/postgresql-trim-function) - [UPPER](https://neon.com/postgresql/postgresql-string-functions/postgresql-upper)