clj-sql-pred

Convert simple sql statements to predicates for filtering collections of Clojure/ ClojureScript maps.

The sql-pred function in the core namespace takes a sql like string and returns a Clojure predicate function that works on maps.

allowed sql keywords: and, or, =, not, in, >, >=, <, <=

Clojars

[clj-sql-pred "0.1.1"]

Example usage:

clj-sql-pred.core> (def coll [{:a "clouds" :c 20} {:a "trains" :b "red" :c 35}])
#'clj-sql-pred.core/coll

clj-sql-pred.core> (filter (sql-pred "c = 20" :keywordize-keys? true) coll)
({:a "clouds", :c 20})

clj-sql-pred.core> (filter (sql-pred "c > 20" :keywordize-keys? true) coll)
({:a "trains", :b "red", :c 35})

clj-sql-pred.core> (filter (sql-pred "c > 19 and c < 50" :keywordize-keys? true) coll)
({:a "clouds", :c 20} {:a "trains", :b "red", :c 35})

clj-sql-pred.core> (filter (sql-pred "c > 19 or c < 50" :keywordize-keys? true) coll)
({:a "clouds", :c 20} {:a "trains", :b "red", :c 35})

clj-sql-pred.core> (filter (sql-pred "a = clouds" :keywordize-keys? true) coll)
({:a "clouds", :c 20})

clj-sql-pred.core> (filter (sql-pred "a in (clouds, trains, bikes, rocks)" :keywordize-keys? true) coll)
({:a "clouds", :c 20} {:a "trains", :b "red", :c 35})

clj-sql-pred.core> (filter (sql-pred "a not in (clouds, bikes, rocks)" :keywordize-keys? true) coll)
({:a "trains", :b "red", :c 35})

clj-sql-pred.core> (filter (sql-pred "a not in (clouds, bikes, rocks) or c = 20" :keywordize-keys? true) coll)
({:a "clouds", :c 20} {:a "trains", :b "red", :c 35})

clj-sql-pred.core> (filter (sql-pred "c not = 20" :keywordize-keys? true) coll)
({:a "trains", :b "red", :c 35})

The keywordize-keys? optional boolean argument determines whether the keywords in your sql-like statement e.g. 'c' is converted to a clojure keyword, e.g. :c before any comparisons are done. In the above examples, that's necessary as the maps in the collection contain :c not "c".

License

MIT