data.table based implementation.
# S3 method for relop_natural_join ex_data_table_step( optree, ..., tables = list(), source_usage = NULL, source_limit = NULL, env = parent.frame() )
| optree | relop operations tree. |
|---|---|
| ... | not used, force later arguments to bind by name. |
| tables | named list map from table names used in nodes to data.tables and data.frames. |
| source_usage | list mapping source table names to vectors of columns used. |
| source_limit | if not null limit all table sources to no more than this many rows (used for debugging). |
| env | environment to work in. |
d1 <- build_frame( "key", "val", "val1" | "a" , 1 , 10 | "b" , 2 , 11 | "c" , 3 , 12 ) d2 <- build_frame( "key", "val", "val2" | "a" , 5 , 13 | "b" , 6 , 14 | "d" , 7 , 15 ) # key matching join optree <- natural_join(local_td(d1), local_td(d2), jointype = "FULL", by = 'key') ex_data_table(optree)#> key val val1 val2 #> 1 a 1 10 13 #> 2 b 2 11 14 #> 3 c 3 12 NA #> 4 d 7 NA 15# full cross-product join # (usually with jointype = "FULL", but "LEFT" is more # compatible with rquery field merge semantics). optree2 <- natural_join(local_td(d1), local_td(d2), jointype = "LEFT", by = NULL) ex_data_table(optree2)#> key val val1 val2 #> 1 a 1 10 13 #> 2 a 1 10 14 #> 3 a 1 10 15 #> 4 b 2 11 13 #> 5 b 2 11 14 #> 6 b 2 11 15 #> 7 c 3 12 13 #> 8 c 3 12 14 #> 9 c 3 12 15# notice ALL non-"by" fields take coalese to left table.