Returns the minimum Y-coordinate of a raster object.

## Syntax
```
HELPCODEESCAPE-sql
float8 ST_YMin(raster raster_obj)
```

## Parameters
<table> <thead> <tr> <th><b>Parameter</b></th> <th><b>Description</b></th> </tr> </thead> <tbody> <tr> <td><code>raster_obj</code></td> <td>The raster object to query.</td> </tr> </tbody> </table>

## Description
`ST_YMin` returns the minimum Y-coordinate of a raster object. If the raster object has not been georeferenced, `ST_YMin` returns `0`.

## Examples
The following example queries the minimum Y-coordinate from `raster_table`.

```
HELPCODEESCAPE-sql
SELECT ST_YMin(rast) AS ymin
FROM raster_table;
```

```
  ymin
--------
    30
```

The value `30` indicates that the raster has been georeferenced. If the raster object has no georeference information, the function returns `0`.

## See also
* [ST_XMin](https://www.alibabacloud.com/help/en/document_detail/176073.html): Returns the minimum X-coordinate of a raster object.

* [ST_YMax](https://www.alibabacloud.com/help/en/document_detail/176076.html): Returns the maximum Y-coordinate of a raster object.

* [ST_XMax](https://www.alibabacloud.com/help/en/document_detail/176075.html): Returns the maximum X-coordinate of a raster object.