---
title: 'PostgreSQL ISNULL'
page_title: 'Looking for PostgreSQL ISNULL? Use COALESCE or CASE'
page_description: 'PostgreSQL does not support the ISNULL function. But you can use the COALESCE() function or CASE expression to achieve the same functionality.'
prev_url: 'https://www.postgresqltutorial.com/postgresql-tutorial/postgresql-isnull/'
ogImage: ''
updatedOn: '2024-02-01T04:01:35+00:00'
enableTableOfContents: true
previousLink:
  title: 'PostgreSQL COALESCE'
  slug: 'postgresql-tutorial/postgresql-coalesce'
nextLink:
  title: 'PostgreSQL NULLIF'
  slug: 'postgresql-tutorial/postgresql-nullif'
---

SQL Server supports [`ISNULL`](http://www.sqlservertutorial.net/sql-server-system-functions/sql-server-isnull-function/) function that replaces `NULL` with a specified replacement value:

```php
ISNULL(expression, replacement)
```

If the `expression` is NULL, then the `ISNULL` function returns the `replacement`. Otherwise, it returns the result of the `expression`.

PostgreSQL does not have the `ISNULL` function. However, you can use the [`COALESCE`](postgresql-coalesce) function which provides similar functionality.

Note that the `COALESCE` function returns the first non\-null argument, so the following syntax has a similar effect as the `ISNULL` function above:

```
COALESCE(expression,replacement)
```

For the `COALESCE` example, check out the [`COALESCE`](postgresql-coalesce) function tutorial.

In addition to `COALESCE` function, you can use the [`CASE`](postgresql-case) expression:

```
SELECT
    CASE WHEN expression IS NULL
            THEN replacement
            ELSE expression
    END AS column_alias;
```

Check out the [`CASE`](postgresql-case) expression tutorial for more information.