---
title: Array Data Type reference
meta:
    description: Documentation for the Array data type.
---

# Array(T)

The `Array(T)` data type stores an ordered collection of elements, where `T` can be any valid data type, including other arrays. Array elements are indexed starting from 1.

## Creating an array

You can create an array using the `array()` function or by enclosing elements in square brackets `[]`.

### Syntax

```sql
array(T)
```

```sql
[]
```

### Example

Creating an array using the `array()` function.

```sql
SELECT array(1, 2, 3) AS my_array, toTypeName(my_array)
```

Result:

```result
┌─my_array─┬─toTypeName(my_array)─┐
│ [1,2,3]  │ Array(UInt8)         │
└──────────┴──────────────────────┘
```

Creating an array using square brackets.

```sql
SELECT ['apple', 'banana', 'cherry'] AS my_fruits, toTypeName(my_fruits)
```

Result:

```result
┌─my_fruits────────────────┬─toTypeName(my_fruits)─┐
│ ['apple','banana','cherry'] │ Array(String)         │
└──────────────────────────┴───────────────────────┘
```

## Working with data types

When an array is created, Tinybird automatically infers the narrowest common data type that can accommodate all its elements. If any element is `NULL`, the array's element type becomes `Nullable`. If elements are incompatible, an error will occur.

### Example

Automatic data type detection with `NULL` values.

```sql
SELECT array(10, 20, NULL) AS mixed_array, toTypeName(mixed_array)
```

Result:

```result
┌─mixed_array─┬─toTypeName(mixed_array)─┐
│ [10,20,NULL] │ Array(Nullable(UInt8))  │
└─────────────┴─────────────────────────┘
```

Attempting to create an array with incompatible data types will result in an error.

```sql
SELECT array(1, 'text')
```

Result:

```text
Received exception from server (version 23.8.1.2984):
Code: 386. DB::Exception: There is no supertype for types UInt8, String because some of them are String/FixedString and some of them are not.
```