fixes #571 by supporting empty order by clause

Signed-off-by: Sean Corfield <sean@corfield.org>

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Changes
 
+* 2.7.next in progress
+  * Fix [#571](https://github.com/seancorfield/honeysql/issues/571) by allowing `:order-by` to take an empty sequence of columns (and be omitted).
+
 * 2.7.1295 -- 2025-03-12
   * Address #570 by adding `:.:.` as special syntax for Snowflake's JSON path syntax, and `:at` as special syntax for general `[`..`]` path syntax.
   * Drop support for Clojure 1.9 [#561](https://github.com/seancorfield/honeysql/issues/561).

doc/clause-reference.md

@@ -1070,6 +1070,9 @@ The `:where` clause can have a single SQL expression, or
 a sequence of SQL expressions prefixed by either `:and`
 or `:or`. See examples of `:where` in various clauses above.
 
+If `:where` is given an empty sequence, the `WHERE` clause will
+be omitted from the generated SQL.
+
 Sometimes it is convenient to construct a `WHERE` clause that
 tests several columns for equality, and you might have a Clojure
 hash map containing those values. `honey.sql/map=` exists to
@@ -1210,12 +1213,15 @@ user=> (sql/format {:select [[[:over
 
 ## order-by
 
-`:order-by` accepts a sequence of one or more ordering
+`:order-by` accepts a sequence of zero or more ordering
 expressions. Each ordering expression is either a simple
 SQL entity or a pair of a SQL expression and a direction
 (which can be `:asc`, `:desc`, `:nulls-first`, `:desc-null-last`,
 etc -- or the symbol equivalent).
 
+If `:order-by` is given an empty sequence, the `ORDER BY` clause will
+be omitted from the generated SQL.
+
 If you want to order by an expression, you should wrap it
 as a pair with a direction:
 

src/honey/sql.cljc

@@ -1119,11 +1119,13 @@
         dirs (map #(when (sequential? %) (second %)) xs)
         [sqls params]
         (format-expr-list (map #(if (sequential? %) (first %) %) xs))]
-    (into [(str (sql-kw k) " "
+    (if (seq sqls)
-                (join ", " (map (fn [sql dir]
+      (into [(str (sql-kw k) " "
-                                  (str sql " " (sql-kw (or dir :asc))))
+                  (join ", " (map (fn [sql dir]
-                                sqls
+                                    (str sql " " (sql-kw (or dir :asc))))
-                                dirs)))] params)))
+                                  sqls
+                                  dirs)))] params)
+      [])))
 
 (defn- format-lock-strength [k xs]
   (let [[strength tables nowait] (ensure-sequential xs)]
@@ -1771,7 +1773,7 @@
        (if (seq leftover)
          (throw (ex-info (str "These SQL clauses are unknown or have nil values: "
                               (join ", " (keys leftover))
-                              "(perhaps you need [:lift {"
+                              " (perhaps you need [:lift {"
                               (first (keys leftover))
                               " ...}] here?)")
                          leftover))

test/honey/sql_test.cljc

@@ -1486,6 +1486,24 @@ ORDER BY id = ? DESC
                            (h/select :*)
                            (h/from :table)))))))
 
+(deftest issue-571
+  (testing "an empty where clause is omitted"
+    (is (= ["SELECT * FROM foo"]
+           (sut/format {:select :* :from :foo :where []})))
+    #?(:clj
+       (is (thrown? clojure.lang.ExceptionInfo
+                    (sut/format {:select :* :from :foo :where nil}))))
+    (is (= ["SELECT * FROM foo WHERE 1 = 1"]
+           (sut/format {:select :* :from :foo :where [:= 1 1]} {:inline true}))))
+  (testing "an empty order by clause is omitted"
+    (is (= ["SELECT * FROM foo"]
+           (sut/format {:select :* :from :foo :order-by []})))
+    #?(:clj
+       (is (thrown? clojure.lang.ExceptionInfo
+                    (sut/format {:select :* :from :foo :order-by nil}))))
+    (is (= ["SELECT * FROM foo ORDER BY bar ASC"]
+           (sut/format {:select :* :from :foo :order-by [:bar]})))))
+
 (comment
   ;; partial (incorrect!) workaround for #407:
   (sut/format {:select :f.* :from [[:foo [:f :for :system-time]]] :where [:= :f.id 1]})