---
title: Struct functions
description: Scalar functions for manipulating structs
image: https://developers.cloudflare.com/dev-products-preview.png
---

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# Struct functions

_Cloudflare Pipelines scalar function implementations are based on [Apache DataFusion ↗](https://arrow.apache.org/datafusion/) (via [Arroyo ↗](https://www.arroyo.dev/)) and these docs are derived from the DataFusion function reference._

## `struct`

Returns an Arrow struct using the specified input expressions. Fields in the returned struct use the `cN` naming convention. For example: `c0`, `c1`, `c2`, etc.

```
struct(expression1[, ..., expression_n])
```

For example, this query converts two columns `a` and `b` to a single column with a struct type of fields `c0` and `c1`:

```
select * from t;+---+---+| a | b |+---+---+| 1 | 2 || 3 | 4 |+---+---+
select struct(a, b) from t;+-----------------+| struct(t.a,t.b) |+-----------------+| {c0: 1, c1: 2}  || {c0: 3, c1: 4}  |+-----------------+
```

#### Arguments

* **expression\_n**: Expression to include in the output struct. Can be a constant, column, or function, and any combination of arithmetic or string operators.

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