PostgreSQL SPLIT_PART() Function

Summary: in this tutorial, you will learn how to use the PostgreSQL SPLIT_PART() function to retrieve a part of a string at a specified position after splitting.

Introduction to the PostgreSQL SPLIT_PART() function

The SPLIT_PART() function splits a string on a specified delimiter and returns the nth substring.

The following illustrates the syntax of the PostgreSQL SPLIT_PART() function:

SPLIT_PART(string, delimiter, position)

The SPLIT_PART() function requires three arguments:

1) string

This is the string to be split.

2) delimiter

The delimiter is a string used as the delimiter for splitting.

3) position

This is the position of the part to return, starting from 1. The position must be a positive integer.

If the position is greater than the number of parts after splitting, the SPLIT_PART() function returns an empty string.

The SPLIT_PART() function returns a part as a string at a specified position.

PostgreSQL SPLIT_PART() function examples

Let’s take some examples of using the PostgreSQL SPLIT_PART() function.

1) Basic PostgreSQL SPLIT_PART() function example

The following example uses the SPLIT_PART() function to split a string by a comma (,) and returns the third substring:

SELECT SPLIT_PART('A,B,C', ',', 2);

The string 'A,B,C' is split on the comma delimiter (,) that results in 3 substrings: ‘A’, ‘B’, and ‘C’.

Because the position is 2, the function returns the 2nd substring which is ‘B’.

Here is the output:

split_part
------------
 B
(1 row)

1) Using PostgreSQL SPLIT_PART() function with a position that does not exist

The following example returns an empty string because the position is greater than the number of parts (3):

SELECT SPLIT_PART('A,B,C', ',', 4) result;

Output:

result
--------

(1 row)

3) Using the SPLIT_PART() function with table data

See the following payment table in the sample database.

payment table The following statement uses the SPLIT_PART() function to return the year and month of the payment date:

SELECT
    split_part(payment_date::TEXT,'-', 1) y,
    split_part(payment_date::TEXT,'-', 2) m,
    amount
FROM
    payment;

Output:

y   | m  | amount
------+----+--------
 2007 | 02 |   7.99
 2007 | 02 |   1.99
 2007 | 02 |   7.99
...

Summary

Use the PostgreSQL SPLIT_PART() function to retrieve a part of a string at a specified position after splitting.