描述

返回一个光栅，其中在给定位置（索引）添加了一个新波段，该波段具有给定的类型、给定的初始值和给定的 NoData 值。如果未指定索引，则将波段添加到末尾。如果未指定 fromband，则假定为波段 1。像素类型是 ST_BandPixelType 中指定的一种像素类型的字符串表示形式。如果指定了现有索引，则所有后续波段 >= 该索引都将增加 1。如果指定的初始值大于像素类型的最大值，则初始值将设置为像素类型允许的最大值。

对于采用 addbandarg 数组的变体（变体 1），特定 addbandarg 的索引值相对于栅格，当时由该 addbandarg 描述的波段正在被添加到栅格中。请参见下面的多个新波段示例。

对于采用栅格数组的变体（变体 5），如果 torast 为 NULL，则数组中每个栅格的 fromband 波段将累积到一个新栅格中。

对于采用 outdbfile 的变体（变体 6 和 7），该值必须包括栅格文件的完整路径。该文件还必须可供 postgres 服务器进程访问。

增强：添加了对 addbandarg 的 2.1.0 支持。

增强：添加了对新的 out-db 波段的 2.1.0 支持。

示例：单个新波段

-- Add another band of type 8 bit unsigned integer with pixels initialized to 200
UPDATE dummy_rast
    SET rast = ST_AddBand(rast,'8BUI'::text,200)
WHERE rid = 1;
                

-- Create an empty raster 100x100 units, with upper left  right at 0, add 2 bands (band 1 is 0/1 boolean bit switch, band2 allows values 0-15)
-- uses addbandargs
INSERT INTO dummy_rast(rid,rast)
    VALUES(10, ST_AddBand(ST_MakeEmptyRaster(100, 100, 0, 0, 1, -1, 0, 0, 0),
    ARRAY[
        ROW(1, '1BB'::text, 0, NULL),
        ROW(2, '4BUI'::text, 0, NULL)
            ]::addbandarg[]
     )
    );

-- output meta data of raster bands to verify all is right --
SELECT  (bmd).*
FROM (SELECT ST_BandMetaData(rast,generate_series(1,2)) As bmd
    FROM dummy_rast WHERE rid = 10) AS foo;
 --result --
 pixeltype | nodatavalue | isoutdb | path
-----------+----------------+-------------+---------+------
 1BB       |             | f       |
 4BUI      |             | f       |


-- output meta data of raster -
SELECT  (rmd).width, (rmd).height, (rmd).numbands
FROM (SELECT ST_MetaData(rast) As rmd
    FROM dummy_rast WHERE rid = 10) AS foo;
-- result --
 upperleftx | upperlefty | width | height | scalex | scaley | skewx | skewy | srid | numbands
------------+------------+-------+--------+------------+------------+-------+-------+------+----------
          0 |          0 |   100 |    100 |      1 |     -1 |     0 |     0 |   0 |        2
                

示例：多个新波段

SELECT
    *
FROM ST_BandMetadata(
    ST_AddBand(
        ST_MakeEmptyRaster(10, 10, 0, 0, 1, -1, 0, 0, 0),
        ARRAY[
            ROW(NULL, '8BUI', 255, 0),
            ROW(NULL, '16BUI', 1, 2),
            ROW(2, '32BUI', 100, 12),
            ROW(2, '32BF', 3.14, -1)
        ]::addbandarg[]
    ),
    ARRAY[]::integer[]
);

 bandnum | pixeltype | nodatavalue | isoutdb | path
---------+-----------+-------------+---------+------
       1 | 8BUI      |           0 | f       |
       2 | 32BF      |          -1 | f       |
       3 | 32BUI     |          12 | f       |
       4 | 16BUI     |           2 | f       |
                

-- Aggregate the 1st band of a table of like rasters into a single raster
-- with as many bands as there are test_types and as many rows (new rasters) as there are mice
-- NOTE: The ORDER BY test_type is only supported in PostgreSQL 9.0+
-- for 8.4 and below it usually works to order your data in a subselect (but not guaranteed)
-- The resulting raster will have a band for each test_type alphabetical by test_type
-- For mouse lovers: No mice were harmed in this exercise
SELECT
    mouse,
    ST_AddBand(NULL, array_agg(rast ORDER BY test_type), 1) As rast
FROM mice_studies
GROUP BY mouse;
                

示例：新的 Out-db 波段

SELECT
    *
FROM ST_BandMetadata(
    ST_AddBand(
        ST_MakeEmptyRaster(10, 10, 0, 0, 1, -1, 0, 0, 0),
        '/home/raster/mytestraster.tif'::text, NULL::int[]
    ),
    ARRAY[]::integer[]
);

 bandnum | pixeltype | nodatavalue | isoutdb | path
---------+-----------+-------------+---------+------
       1 | 8BUI      |             | t       | /home/raster/mytestraster.tif
       2 | 8BUI      |             | t       | /home/raster/mytestraster.tif
       3 | 8BUI      |             | t       | /home/raster/mytestraster.tif
                

另请参见

ST_BandMetaData、ST_BandPixelType、ST_MakeEmptyRaster、ST_MetaData、ST_NumBands、ST_Reclass