# String Concatenation Operator (`||`)

**Applies to:** ✅ Data 360 SQL ✅ Tableau Hyper API

Concatenates two strings or a string and a non-string value, returning NULL if either operand is NULL.

## Syntax

```sql
<string> || <right_value>
```

## Arguments

### Required

- `<left_string>`: The first string to concatenate.
- `<right_value>`: The second value to concatenate.

## Returns

Returns a text value that contains the concatenated strings, or NULL if either operand is NULL.

## Considerations

- NULL arguments are NOT ignored. If either operand is NULL, the result is NULL.
- This differs from the `concat` function, which ignores NULL arguments.

## Examples

### Basic Concatenation

Concatenate two string literals.

```sql
SELECT 'Hy' || 'per' AS result;
```

Returns `'Hyper'`.

### Concatenation with NULL

Demonstrate NULL handling.

```sql
SELECT 'Hy' || NULL AS result;
```

Returns `NULL` because one operand is NULL.

### String with Integer

Concatenate a string with a number.

```sql
SELECT 'Value: ' || 42 AS result;
```

Returns `'Value: 42'`.

## Related Documentation

- [String Types](/docs/data/data-cloud-query-guide/references/dc-sql-reference/string.md)