move SQL out of code using HugSQL

project.clj

@@ -13,7 +13,8 @@
                  [ring-middleware-format "0.7.2"]
                  [org.clojure/data.json "0.2.6"]
                  [ring/ring-json "0.4.0"]
-                 [ring/ring-jetty-adapter "1.4.0"]]
+                 [ring/ring-jetty-adapter "1.4.0"]
+                 [com.layerware/hugsql "0.4.8"]]
   :plugins [[lein-ring "0.9.7"] [lein-environ "1.1.0"]]
   :ring {:handler aretherecookies.app/app}
   :profiles

src/aretherecookies/db.clj

@@ -1,66 +1,32 @@
 (ns aretherecookies.db
-    (:require
-            [clojure.java.jdbc :as jdbc]
+  (:require [clojure.java.jdbc :as jdbc]
             [environ.core :refer [env]]
-            [clojure.string :as str])
-    (:import com.mchange.v2.c3p0.ComboPooledDataSource))
+            [clojure.string :as str]
+            [hugsql.core :as hugsql])
+  (:import com.mchange.v2.c3p0.ComboPooledDataSource))
 
-(def db-spec {
-    :uri (env :database-jdbc-uri)
-    :password (env :database-password)
-    :user (env :database-user)
-    :name (env :database-name)
-})
+(hugsql/def-db-fns "aretherecookies/queries.sql")
+
+(def db-spec {:uri (env :database-jdbc-uri)
+              :password (env :database-password)
+              :user (env :database-user)
+              :name (env :database-name)})
 
 (defn pool
-    [spec]
-    (let [cpds (doto (ComboPooledDataSource.)
-        (.setDriverClass "org.postgresql.Driver")
-        (.setJdbcUrl (str "jdbc:" (:uri spec)))
-        (.setUser (:user spec))
-        (.setPassword (:password spec))
+  [spec]
+  (let [cpds (doto (ComboPooledDataSource.)
+               (.setDriverClass "org.postgresql.Driver")
+               (.setJdbcUrl (str "jdbc:" (:uri spec)))
+               (.setUser (:user spec))
+               (.setPassword (:password spec))
         ;; expire excess connections after 30 minutes of inactivity:
-        (.setMaxIdleTimeExcessConnections (* 30 60))
+               (.setMaxIdleTimeExcessConnections (* 30 60))
         ;; expire connections after 3 hours of inactivity:
-        (.setMaxIdleTime (* 3 60 60)))]
+               (.setMaxIdleTime (* 3 60 60)))]
     (println (str "jdbc:" (:url spec)))
     {:datasource cpds}))
 
-(def pooled-db (delay (pool db-spec)))
+(defonce pooled-db (delay (pool db-spec)))
 
-(def location-query "
-SELECT
-    id,
-    name,
-    place_id,
-    category,
-    images,
-    thumbImage,
-    ST_AsGeoJSON(loc) as location,
-    ST_Distance(
-    loc, 
-    @LOCATION@
-    ) / 1609 as distance
-FROM food_items 
-WHERE 
-    ST_DWithin(
-    loc,
-    @LOCATION@,
-    @DISTANCE@ * 1609
-    )
-ORDER BY distance ASC;")
-
-(defn point-text [lng lat] 
-    (-> 
-        "ST_GeogFromText('SRID=4326;POINT(@LONGITUDE@ @LATITUDE@)')" 
-        (str/replace "@LONGITUDE@" (str lng)) 
-        (str/replace "@LATITUDE@" (str lat))))
-
-(defn build-fooditems-query [lng lat dist]
-    (-> 
-        location-query
-        (str/replace "@LOCATION@" (point-text (str lng) (str lat)))
-        (str/replace "@DISTANCE@" (str dist))))
-
-(defn query-food-items [query]
-    (jdbc/query @pooled-db [query]))
+(defn query-food-items-by-distance [{:keys [lat lng radius]}]
+  (food-items-by-distance @pooled-db {:dist radius :lng lng :lat lat}))

src/aretherecookies/handler.clj

@@ -1,5 +1,5 @@
 (ns aretherecookies.handler
-  (:require [aretherecookies.db :refer [query-food-items build-fooditems-query]]
+  (:require [aretherecookies.db :refer [query-food-items-by-distance]]
             [compojure.core :refer :all]
             [compojure.route :as route]
             [clojure.data.json :as json]
@@ -41,8 +41,10 @@
      (hash-map
       :orderby orderby
       :filter filter
-      :fooditems (food-items-to-json
-                  (query-food-items (build-fooditems-query lng lat (get filter "radius")))))
+      :fooditems (food-items-to-json 
+        (query-food-items-by-distance {:lat lat
+                                                                    :lng lng
+                                                                    :radius (get filter "radius")})))
      :value-fn uuid-to-string)))
 
 (defroutes app-routes

src/aretherecookies/queries.sql

@@ -0,0 +1,13 @@
+-- :name food-items-by-distance :raw
+SELECT
+    id,
+    name,
+    place_id,
+    category,
+    images,
+    thumbImage,
+    ST_AsGeoJSON(loc) as location,
+    ST_Distance(loc, ST_SetSRID(ST_Point(:lng, :lat),4326)::geography) / 1609 as distance
+FROM food_items 
+WHERE ST_DWithin(loc, ST_SetSRID(ST_Point(:lng, :lat),4326)::geography, :dist * 1609)
+ORDER BY distance ASC