address #415 by supporting multi-column add/alter/modify

src/honey/sql.cljc

@@ -959,10 +959,14 @@
         (str/join ", " (map #'format-single-column xs))
         ")")])
 
-(defn- format-add-item [k spec]
+(defn- format-add-single-item [k spec]
   (if (contains? #{:if-not-exists 'if-not-exists} (last spec))
-    [(str (sql-kw k) " " (sql-kw :if-not-exists) " " (format-single-column (butlast spec)))]
-    [(str (sql-kw k) " " (format-single-column spec))]))
+    (str (sql-kw k) " " (sql-kw :if-not-exists) " " (format-single-column (butlast spec)))
+    (str (sql-kw k) " " (format-single-column spec))))
+
+(defn- format-add-item [k spec]
+  (let [items (if (and (sequential? spec) (sequential? (first spec))) spec [spec])]
+    [(str/join ", " (for [item items] (format-add-single-item k item)))]))
 
 (defn- format-rename-item [k [x y]]
   [(str (sql-kw k) " " (format-entity x) " TO " (format-entity y))])

src/honey/sql/helpers.cljc

@@ -138,6 +138,12 @@
       (helper-merge data k args))
     (helper-merge {} k args)))
 
+(defn- generic-grouped [k args]
+  (if (map? (first args))
+    (let [[data & args] args]
+      (helper-merge data k [args]))
+    (helper-merge {} k [args])))
+
 (defn- generic-1 [k [data arg]]
   (if (map? data)
     (assoc data k arg)
@@ -169,7 +175,7 @@
 
   (add-column :name [:varchar 32] [:not nil])"
   [& col-elems]
-  (generic :add-column col-elems))
+  (generic-grouped :add-column col-elems))
 
 (defn drop-column
   "Takes one or more column names (use with `alter-table`).
@@ -188,7 +194,7 @@
 
   (alter-column :name [:varchar 64] [:not nil])"
   [& col-elems]
-  (generic :alter-column col-elems))
+  (generic-grouped :alter-column col-elems))
 
 (defn modify-column
   "Like add-column, accepts any number of SQL elements
@@ -199,7 +205,7 @@
   MySQL-specific, deprecated. Use `alter-column` and
   specify the MySQL dialect to get `MODIFY COLUMN`."
   [& col-elems]
-  (generic :modify-column col-elems))
+  (generic-grouped :modify-column col-elems))
 
 (defn rename-column
   "Accepts two column names: the original name and the

test/honey/sql/helpers_test.cljc

@@ -631,6 +631,11 @@
   (is (= (sql/format (-> (alter-table :fruit)
                          (add-column :id :int [:not nil])))
          ["ALTER TABLE fruit ADD COLUMN id INT NOT NULL"]))
+  (is (= (sql/format (-> (alter-table :fruit)
+                         (add-column :id :int [:not nil])
+                         (add-column :a1 :int nil)
+                         (add-column :be :text [:not nil])))
+         ["ALTER TABLE fruit ADD COLUMN id INT NOT NULL, ADD COLUMN a1 INT NULL, ADD COLUMN be TEXT NOT NULL"]))
   (is (= (sql/format (alter-table :fruit
                                   (add-column :id :int [:not nil])
                                   (drop-column :ident)