mrp_col_unique {mregions2} | R Documentation |
Get all the possible values of a column of a Marine Regions data product
Description
Get all the possible values of a column of a Marine Regions data product
Usage
mrp_col_unique(layer, colname)
mrp_col_distinct(layer, colname)
Arguments
layer |
(character) Identifier of the data product. See mrp_list |
colname |
(character) Column name in the data product. See |
Details
This function becomes useful to write CQL or OGC filters that you can pass to mrp_get()
or mrp_view()
as
it helps to know all the possible values in the column name that you want to query on beforehand. Use it
together with mrp_colnames()
to know the columns and data types in the data product.
Geometry columns
Note that columns of type geometry
are forbidden as their performance is sub-optimal and would likely
crash your R session.
Value
A numeric or character vector with the unique values of a column of a Marine Regions data product.
See Also
mrp_list to describe the list of products, mrp_colnames()
to get the names and data type of
the columns of a data product, useful to write queries that can be passed to mrp_get()
or mrp_view()
via
the arguments cql_filter
or filter
.
Examples
mrp_col_unique("ecs", "pol_type")
mrp_col_unique("ecs_boundaries", "line_type")