描述

返回有关栅格标注栏的基本元数据。返回的列：象素类型、nodatavalue、isoutdb、路径、outdbband num、文件大小、文件时间戳。

	如果栅格不包含波段，则会引发错误。

	如果BAND没有NODATA值，则nodatavue为空。

	如果isoutdb为FALSE，则路径、outDBband num、文件大小和文件时间戳为空。如果禁用outdb访问，则文件大小和文件时间戳也将为空。

增强版：2.5.0以包括 输出数据库带宽 ， 文件大小 和 文件时间戳 用于outdb栅格。

示例：变体1

SELECT
    rid,
    (foo.md).*
FROM (
    SELECT
        rid,
        ST_BandMetaData(rast, 1) AS md
    FROM dummy_rast
    WHERE rid=2
) As foo;

 rid | pixeltype | nodatavalue | isoutdb | path | outdbbandnum
-----+-----------+---- --------+---------+------+--------------
   2 | 8BUI      |           0 | f       |      |
                

示例：变体2

WITH foo AS (
    SELECT
        ST_AddBand(NULL::raster, '/home/pele/devel/geo/postgis-git/raster/test/regress/loader/Projected.tif', NULL::int[]) AS rast
)
SELECT
    *
FROM ST_BandMetadata(
    (SELECT rast FROM foo),
    ARRAY[1,3,2]::int[]
);

 bandnum | pixeltype | nodatavalue | isoutdb |                                      path                                      | outdbbandnum  | filesize | filetimestamp |
---------+-----------+-------------+---------+--------------------------------------------------------------------------------+---------------+----------+---------------+-
       1 | 8BUI      |             | t       | /home/pele/devel/geo/postgis-git/raster/test/regress/loader/Projected.tif      |            1  |    12345 |    1521807257 |
       3 | 8BUI      |             | t       | /home/pele/devel/geo/postgis-git/raster/test/regress/loader/Projected.tif      |            3  |    12345 |    1521807257 |
       2 | 8BUI      |             | t       | /home/pele/devel/geo/postgis-git/raster/test/regress/loader/Projected.tif      |            2  |    12345 |    1521807257 |
                

另请参阅

ST_MetaData, ST_BandPixelType