fixes #344 by special-casing MySQL SET

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Changes
 
 * 2.0.next in progress ("gold" mid-August?)
+  * Fixes #344 by no longer dropping the qualifier on columns in a `SET` clause _for the `:mysql` dialect only_; the behavior is unchanged for all other dialects.
   * Fixes #340 by making hyphen to space logic more general so _operators_ containing `-` should retain the hyphen without special cases.
   * Documentation improvements: `:fetch`, `:lift`, `:limit`, `:offset`, `:param`, `:select`; also around JSON/PostgreSQL.
   * Link to the [HoneySQL web app](https://www.john-shaffer.com/honeysql/) in both the README and **Getting Started**.

src/honey/sql.cljc

@@ -127,6 +127,11 @@
                    (symbol (name clause))
                    (keyword (name clause))))))
 
+(defn- mysql?
+  "Helper to detect if MySQL is the current dialect."
+  []
+  (= :mysql (:dialect *dialect*)))
+
 (defn- sql-server?
   "Helper to detect if SQL Server is the current dialect."
   []
@@ -641,7 +646,7 @@
   (let [[sqls params]
         (reduce-kv (fn [[sql params] v e]
                      (let [[sql' & params'] (format-expr e)]
-                       [(conj sql (str (format-entity v {:drop-ns true}) " = " sql'))
+                       [(conj sql (str (format-entity v {:drop-ns (not (mysql?))}) " = " sql'))
                         (if params' (into params params') params)]))
                    [[] []]
                    xs)]

test/honey/sql_test.cljc

@@ -378,11 +378,21 @@
   (is (=
        ["UPDATE `foo` INNER JOIN `bar` ON `bar`.`id` = `foo`.`bar_id` SET `a` = ? WHERE `bar`.`b` = ?" 1 42]
        (->
-         {:update :foo
-          :join   [:bar [:= :bar.id :foo.bar_id]]
-          :set    {:a 1}
-          :where  [:= :bar.b 42]}
-         (format {:dialect :mysql})))))
+        {:update :foo
+         :join   [:bar [:= :bar.id :foo.bar_id]]
+         :set    {:a 1}
+         :where  [:= :bar.b 42]}
+        (format {:dialect :mysql}))))
+  ;; issue 344
+  (is (=
+       ["UPDATE `foo` INNER JOIN `bar` ON `bar`.`id` = `foo`.`bar_id` SET `f`.`a` = ? WHERE `bar`.`b` = ?" 1 42]
+       (->
+        {:update :foo
+         :join   [:bar [:= :bar.id :foo.bar_id]]
+         ;; do not drop ns in set clause for MySQL:
+         :set    {:f/a 1}
+         :where  [:= :bar.b 42]}
+        (format {:dialect :mysql})))))
 
 (deftest format-arity-test
   (testing "format can be called with no options"