# Arrays

#### Create an array field

You can create array fields using the `..[]` syntax:

```sql
CREATE TABLE table(
    _key INT,
    , fialdA INT[]            -- Simple array
    , fieldB.fieldC STRING[]) -- Array in a subfield
    , fieldD INT[][]          -- Nested array
FORMAT(avro, avro);
```

#### Select an array field

Tables can store data containing arrays. Here is a SQL statement for querying an array item:

```sql
SELECT
    fieldA[1]
     , fieldB.fieldC[2].x
FROM table
WHERE fieldA[1] LIKE '%Lenses%'
```

When working with arrays is good to check the array bounds. See the `SIZEOF` function in the list of supported functions.

#### Query for array size

Sometimes you want to find out how many items are in your array. To do so you can run:

{% code overflow="wrap" %}

```sql
SELECT
    SIZEOF(arrayFieldA)
FROM table
```

{% endcode %}


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