'Getting data from queryparser
I am attempting to use queryparser to extract table relationships from an SQL query. I can get most of what I need, I'm just having issues unpacking the lists.
library(queryparser)
file <- "select
p.name,
p.age,
p.hometown,
c.state,
c.country,
n.capitol,
n.leader
from person p
inner join city c
on p.hometown = c.name
inner join nation n
on c.county = n.name
where C.country != 'Antarctica' "
query <- parse_query(file, tidyverse = TRUE)
query$from
yields the following lists:
> query$from
$p
person
$c
city
$n
nation
attr(,"join_types")
[1] "inner join" "inner join"
attr(,"join_conditions")
attr(,"join_conditions")[[1]]
p.hometown == c.name
attr(,"join_conditions")[[2]]
c.county == n.name
I would like to have a datafame that has each table name and it's alias, and a second table with the join criteria. What is the easiest way to do this dynamically so that I don't have to adjust code between scanning different scripts?
Sources
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