获得raster对象的元数据,返回JSON格式。
语法
text ST_MetaData(raster raster_obj);
text ST_MetaData(raster raster_obj,
text key);
text ST_MetaData(raster raster_obj,
integer band,
text key);
参数
参数名称 | 描述 |
raster_obj | raster对象。 |
band | 波段序号,从0开始。 |
key | 需要查询的元数据项名称,如果传入的是 |
示例
select ST_MetaData(raster_obj) from raster_table;
-- meta data with a name
SELECT ST_MetaData(raster_obj, 'swh#scale_factor')
FROM raster_table;
st_metadata
-----------------------
0.0001488117874873806
-- all meta data
SELECT ST_MetaData(raster_obj, 'all')
FROM raster_table;
st_metadata
-----------------------
{"AREA_OR_POINT":"Area"}
-- meta data with a name of a band
SELECT ST_MetaData(raster_obj, 0, 'NETCDF_DIM_time')
FROM raster_table;
st_metadata
-------------
1043112
-- all meta data of a band
SELECT ST_MetaData(raster_obj, 0, 'all')
FROM raster_table;
st_metadata
----------------------------------------------------------------------------------------------------------------------------------------
{"add_offset":"4.907141431495487","long_name":"Significant height of combined wind waves and swell","missing_value":"-32767","NETCDF_DI.
M_time":"1043112","NETCDF_VARNAME":"swh","scale_factor":"0.0001488117874873806","units":"m","_FillValue":"-32767"}
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