ST_BandNoDataValue
Name
ST_BandNoDataValue — Returns the value in a given band that represents no data. If no band num 1 is assumed.
Synopsis
    
     double precision
     
      ST_BandNoDataValue
     
     (
    
    raster
    
     rast
    
    , integer
    
     bandnum=1
    
    
     )
    
    ;