diff options
Diffstat (limited to 'src/clojure_sql/dsl.clj')
| -rw-r--r-- | src/clojure_sql/dsl.clj | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/src/clojure_sql/dsl.clj b/src/clojure_sql/dsl.clj index 6ba81bc..0a05763 100644 --- a/src/clojure_sql/dsl.clj +++ b/src/clojure_sql/dsl.clj @@ -177,7 +177,8 @@ (and (nil? (:group query)) (nil? (:having query)) (nil? (:take query)) - (nil? (:drop query)))) + (nil? (:drop query)) + (nil? (:set-operation query)))) (defn ^:private convert-to-subquery [query] (-> (table query) @@ -195,7 +196,7 @@ (def ^:private valid-join-type? (comp boolean #{:cross :inner :outer :full-outer})) (defn join - "Join two queries into one query The fields of the resultant query + "Join two queries into one query. The fields of the resultant query will be the union of the argument queries. If `type` is not provided then the join type will be automatically @@ -376,3 +377,22 @@ (if-let [old-drop (:drop query)] (assoc query :drop (+ old-drop n)) (assoc query :drop n)))) + +(defn ^:private union-compatible? [& queries] + (apply = (map (comp set keys :fields) queries))) + +(defn union + "Combine the results of two queries" + [& queries] + (assert (apply union-compatible? queries) "Unioned queries must expose the same fields.") + (assoc (q/->Query) + :set-operation :union + :queries queries)) + +(defn intersection + "Take the common rows in two queries" + [& queries] + (assert (apply union-compatible? queries) "Unioned queries must expose the same fields.") + (assoc (q/->Query) + :set-operation :intersect + :queries queries)) |