This topic describes the ST_ExportTo function. This function is used to export a raster object as an Object Storage Service (OSS) object, a Multi-Cloud Object Storage (MinIO) object, or a Hadoop Distributed File System (HDFS) file.
Syntax
boolean ST_ExportTo(raster source,
cstring format,
cstring url,
integer level = 0);
Parameters
Parameter | Description |
---|---|
source | The raster object that you want to export. |
format | The format of the exported data, such as GTiff or BMP. |
url | The URL of the exported OSS object, MinIO object, or HDFS file. This function does not support an URL that specifies a subset. For more information, see Object storage paths. |
level | The pyramid level. |
The format parameter specifies the format of the exported data. The following table
lists common formats.
Format | Full name |
---|---|
BMP | Microsoft Windows Device Independent Bitmap(.bmp) |
ECW | ERDAS Compressed Wavelets (.ecw) |
EHdr | ESRI .hdr Labelled |
GIF | Graphics InterchangeFormat(.gif) |
GPKG | GeoPackage |
GTiff | TIFF/BigTIFF/GeoTIFF(.tif) |
HDF4 | Hierarchical Data Format Release 4 (HDF4) |
Geospatial PDF | |
PNG | Portable Network Graphics (.png) |
COG | Cloud optimized GeoTIFF |
Description
If the raster object is exported, the function returns true. If the raster object fails to be exported, the function returns false.
You can obtain the supported data types by using the ST_RasterDrivers function.
Examples
-- Export a raster object as an OSS object.
Select ST_ExportTo(raster, 'GTiff', 'OSS://<ak>:<ak_secret>@oss-cn-beijing-internal.aliyuncs.com/mybucket/data/image.tif')
from raster_table
where id=1;
-- Export a raster object as a MinIO object.
Select ST_ExportTo(raster, 'PNG', 'MIO://<ak>:<ak_secret>@10.0.XX.XX:443/mybucket/data/image.png')
from raster_table
where id=1;
-- Export a raster object as an HDFS file.
Select ST_ExportTo(raster, 'PNG', 'HDFS://<user_name>@10.0.XX.XX:8020/path/image.png')
from raster_table
where id=1;