## Syntax
```mermaid
%%{init: {
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'themeVariables': {
'fontSize': '11px',
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flowchart LR
Start((START)) --> QUOTE_NULLABLE[QUOTE_NULLABLE]:::quoted
QUOTE_NULLABLE --> End((END))
```
## Purpose
The `QUOTE_NULLABLE` SQL function quotes a text for use as a literal within an SQL query, identical to [[QUOTE_LITERAL]]. However, when the input is `null` or empty the function returns `null`.
See also [[QUOTE_IDENT]] and [[QUOTE_LITERAL]].
Parameters:
- Literal (`varchar2`): the text to quote.
Returns: the quoted literal as `varchar2`. Returns `null` when the input is `null` or empty.
## Examples
The following example quotes `abc`:
```sql
select quote_nullable('abc')
-------------------
"abc"
```
The following example quotes `null`; the output is empty:
```sql
select quote_nullable(null)
-------------------
```