supabase/web/docs/guides/database/arrays.mdx

---
id: arrays
title: "Working With Arrays"
description: How to use arrays in PostgreSQL and the Supabase API.
---

import Tabs from '@theme/Tabs';
import TabItem from '@theme/TabItem';

PostgreSQL supports flexible [array types](https://www.postgresql.org/docs/12/arrays.html).  
These arrays are also supported in the Supabase dashboard and in the Javascript API.

## Steps

### Create a table with an array column

Create a test table with a text array (an array of strings):

<Tabs
defaultValue="UI"
values={[
  {label: 'UI', value: 'UI'},
  {label: 'SQL', value: 'SQL'},
]}>

<TabItem value="UI">

```bash
1. Got the Table Editor
2. Create a New Table
3. Create a new table named `arraytest` and save the table
    - New Column
        - Name the new column `textarray`
        - Make it type `text`
        - Check the box labelled `Define as array`
        - Save the new column
```

</TabItem>

<TabItem value="SQL">

```sql
CREATE TABLE arraytest (id integer NOT NULL, textarray text ARRAY);
```

</TabItem>
</Tabs>





### Insert a record with an array value


<Tabs
defaultValue="UI"
values={[
  {label: 'UI', value: 'UI'},
  {label: 'SQL', value: 'SQL'},
  {label: 'JS', value: 'JavaScript'},
]}>

<TabItem value="UI">

```bash
- Table Editor
- Select `arraytest`
- Insert Row
    - In the `textarray` field input, paste:
    - `["Harry", "Larry", "Moe"]`
    - Save the new row
```

</TabItem>

<TabItem value="SQL">

```sql
INSERT INTO arraytest (id, textarray) VALUES (1, ARRAY['Harry', 'Larry', 'Moe']);    
```

</TabItem>

<TabItem value="JavaScript">
To insert a record from the Javascript client:

```js
const { data, error } = await supabase
.from('arraytest')
.insert([
    { id: 2, textarray: ['one', 'two', 'three', 'four'] }
]);  
```

</TabItem>

</Tabs>


### View the results


<Tabs
defaultValue="UI"
values={[
  {label: 'UI', value: 'UI'},
  {label: 'SQL', value: 'SQL'},
]}>

<TabItem value="UI">

```bash
- Table Editor
- Select `arraytest`
```

Your first array data!

| id  | textarray                    |
| --- | ---------------------------- |
| 1   | ["Harry","Larry","Moe"]      |

</TabItem>
<TabItem value="SQL">

```sql
SELECT * FROM arraytest;
```

Your first array data!

| id  | textarray                    |
| --- | ---------------------------- |
| 1   | ["Harry","Larry","Moe"]      |

</TabItem>
</Tabs>


### Query Array Data

To query an array, PostgreSQL uses 1-based arrays, so be careful, since you're probably used to 0-based arrays in Javascript.

<Tabs
defaultValue="UI"
values={[
  {label: 'SQL', value: 'SQL'},
  {label: 'JS', value: 'JavaScript'},
]}>

<TabItem value="SQL">

To select the first item from the array and get the total length of the array:

```js
SELECT textarray[1], array_length(textarray, 1) FROM arraytest;
```

returns:

| textarray | array_length |
| --------- | ------------ |
| Harry     | 3            |

</TabItem>
<TabItem value="JavaScript">

This returns the entire array field:

```js
const { data, error } = await supabase
.from('arraytest')
.select('textarray[]');
console.log(JSON.stringify(data,null,2));
```

returns:

```js
[
  {
    "textarray": ["Harry", "Larry", "Moe"]
  }
]
```


</TabItem>

</Tabs>

## Resources

* [Supabase JS Client](https://github.com/supabase/supabase-js)
* [Supabase Account - Free Tier OK](https://supabase.io)
* [PostgreSQL Arrays](https://www.postgresql.org/docs/12/arrays.html)