Added support for casts of the form CAST(foo AS type)

src/honeysql/format.clj

@@ -99,6 +99,11 @@
 (defmethod fn-handler "distinct-on" [_ & args]
   (str "DISTINCT ON (" (comma-join (map to-sql args)) ")"))
 
+(defmethod fn-handler "cast" [_ field cast-to-type]
+  (str "CAST" (paren-wrap (str (to-sql field)
+                               " AS "
+                               (to-sql cast-to-type)))))
+
 (defmethod fn-handler "=" [_ a b & more]
   (if (seq more)
     (apply expand-binary-ops "=" a b more)

test/honeysql/core_test.clj

@@ -55,3 +55,9 @@
               "bort" "gabba" 2])))
     (testing "SQL data prints and reads correctly"
       (is (= m1 (read-string (pr-str m1)))))))
+
+(deftest test-cast
+  (is (= ["SELECT foo, CAST(bar AS integer)"]
+         (sql/format {:select [:foo (sql/call :cast :bar :integer)]})))
+  (is (= ["SELECT foo, CAST(bar AS integer)"]
+         (sql/format {:select [:foo (sql/call :cast :bar 'integer)]}))))