NAME

       SPI_modifytuple - create a row by replacing selected fields of a given row

SYNOPSIS

       HeapTuple SPI_modifytuple(Relation rel, HeapTuple row, int ncols,
                                 int * colnum, Datum * values, const char * nulls)

DESCRIPTION

       SPI_modifytuple creates a new row by substituting new values for selected columns, copying
       the original row's columns at other positions. The input row is not modified. The new row
       is returned in the upper executor context.

       This function can only be used while connected to SPI. Otherwise, it returns NULL and sets
       SPI_result to SPI_ERROR_UNCONNECTED.

ARGUMENTS

       Relation rel
           Used only as the source of the row descriptor for the row. (Passing a relation rather
           than a row descriptor is a misfeature.)

       HeapTuple row
           row to be modified

       int ncols
           number of columns to be changed

       int * colnum
           an array of length ncols, containing the numbers of the columns that are to be changed
           (column numbers start at 1)

       Datum * values
           an array of length ncols, containing the new values for the specified columns

       const char * nulls
           an array of length ncols, describing which new values are null

           If nulls is NULL then SPI_modifytuple assumes that no new values are null. Otherwise,
           each entry of the nulls array should be ' ' if the corresponding new value is
           non-null, or 'n' if the corresponding new value is null. (In the latter case, the
           actual value in the corresponding values entry doesn't matter.) Note that nulls is not
           a text string, just an array: it does not need a '\0' terminator.

RETURN VALUE

       new row with modifications, allocated in the upper executor context, or NULL on error (see
       SPI_result for an error indication)

       On error, SPI_result is set as follows:

       SPI_ERROR_ARGUMENT
           if rel is NULL, or if row is NULL, or if ncols is less than or equal to 0, or if
           colnum is NULL, or if values is NULL.

       SPI_ERROR_NOATTRIBUTE
           if colnum contains an invalid column number (less than or equal to 0 or greater than
           the number of columns in row)

       SPI_ERROR_UNCONNECTED
           if SPI is not active