ST_BandNoDataValue
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Name

ST_BandNoDataValue — 返回给定区段中表示无数据的值。如果没有频带数，则假定为1。

Synopsis

double precision ST_BandNoDataValue ( raster rast , integer bandnum=1 ) ;

描述

返回表示波段无数据的值

示例 

SELECT ST_BandNoDataValue(rast,1) As bnval1,
    ST_BandNoDataValue(rast,2) As bnval2, ST_BandNoDataValue(rast,3) As bnval3
FROM dummy_rast
WHERE rid = 2;

 bnval1 | bnval2 | bnval3
--------+--------+--------
      0 |      0 |      0

另请参阅

ST_NumBands

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