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> Reference material for CONCAT function

# CONCAT

Concatenates, i.e. combines, the text representations of all the input parameters without a separator, in the order they are provided.

## Syntax

```sql theme={"theme":{"light":"github-light","dark":"github-dark"}}
CONCAT( <expression>[, <expression>[, ...n]] );
```

**—OR—**

```sql theme={"theme":{"light":"github-light","dark":"github-dark"}}
<expression> || <expression>
```

## Parameters

### `CONCAT` function

| Parameter              | Description                         | Supported input types |
| :--------------------- | :---------------------------------- | :-------------------- |
| `<expression>[, ...n]` | The expressions to be concatenated. | Any type              |

The parameters to the `CONCAT` function can be of any data type, and will be converted to their text representation before concatenation. `NULL` parameters to the `CONCAT` function are treated as empty strings and ignored. If all parameters are `NULL`, the result will be an empty string.

### `||` operator

| Parameter      | Description                         | Supported input types                       |
| :------------- | :---------------------------------- | :------------------------------------------ |
| `<expression>` | The expressions to be concatenated. | Any non-array type, but at least one `TEXT` |

To enable string concatenation, one parameter to the `||` operator must be of type `TEXT`, while the other parameter may be of any non-array data type. If one parameter to the `||` operator is `NULL`, the result will also be the non-null parameter; if both parameters are `NULL`, the result will be `NULL`.

The concatenation operator `||` can also be used for [array concatenation](/reference-sql/functions-reference/array/array-concat).

## Return Type

`TEXT`

## Example

The following example concatenates users' `nicknames` and `emails` from the players table:

```sql theme={"theme":{"light":"github-light","dark":"github-dark"}}
SELECT
	CONCAT(nickname, ': ', email) as user_info
FROM players
LIMIT 5;
```

**Returns**:

| user\_info                                                                 |
| :------------------------------------------------------------------------- |
| steven70: [daniellegraham@example.net](mailto:daniellegraham@example.net)  |
| burchdenise: [keith84@example.org](mailto:keith84@example.org)             |
| stephanie86: [zjenkins@example.org](mailto:zjenkins@example.org)           |
| sabrina21: [brianna65@example.org](mailto:brianna65@example.org)           |
| kennethpark: [williamsdonna@example.com](mailto:williamsdonna@example.com) |