## Syntax
```mermaid
%%{init: {
'theme': 'base',
'flowchart': { 'padding': '7', 'nodeSpacing': '20', 'rankSpacing': '20' },
'themeVariables': {
'fontSize': '11px',
'fontFamily': 'Arial'
}
}}%%
flowchart LR
Start((START)) --> COALESCE[COALESCE]:::quoted
COALESCE --> End((END))
```
## Purpose
The `COALESCE` SQL function performs a coalescing operation.
Parameters:
- Left: an object.
- Right: an object.
Returns: the left value if right is empty, otherwise the right value.