Fixes #162 by adding composite/:composite

Relies on paren-wrapping within subqueries which is the context for 
values.

CHANGES.md

@@ -3,6 +3,7 @@
 * Fix #248 by treating alias as "not a subquery" when generating SQL for it. (@seancorfield)
 * Fix #247 by reverting #132 / #131 so the default behavior is friendlier for namespace-qualified keywords used for table and column names, but adds `honeysql.format/*allow-namespaced-names?*` to restore the previous behavior. A `:allow-namespaced-names?` option has been adding to `format` to set this more easily.
 * Fix #235 by adding `set0` (`:set0`) and `set1` (`:set1`) variants of `sset` (`:set`) to support different placements of `SET` (before `FROM` or after `JOIN` respectively) that different databases require. See also #200. (@seancorfield)
+* Fix #162 by adding `composite`/`:composite` constructor for values. (@seancorfield)
 * Fix #139 by checking arguments to `columns`/`merge-columns` and throwing an exception if a single collection is supplied (instead of varargs). (@seancorfield)
 * Fix #128 by adding `truncate` support. (@seancorfield)
 * Fix #99 by adding a note to the first use of `select` in the README that column names can be keywords or symbols but not strings. (@seancorfield)

README.md

@@ -186,6 +186,21 @@ The column values do not have to be literals, they can be nested queries:
     "user"]
 ```
 
+Composite types are supported:
+
+```clojure
+(-> (insert-into :comp_table)
+    (columns :name :comp_column)
+    (values
+     [["small" (composite 1 "inch")]
+      ["large" (composite 10 "feet")]])
+    sql/format)
+=> [#sql/regularize
+    "INSERT INTO comp_table (name, comp_column)
+     VALUES (?, (?, ?)), (?, (?, ?))"
+    "small" 1 "inch" "large" 10 "feet"]
+```
+
 Updates are possible too (note the double S in `sset` to avoid clashing
 with `clojure.core/set`):
 

src/honeysql/format.cljc

@@ -226,6 +226,7 @@
    :delete-from 80
    :truncate 85
    :columns 90
+   :composite 95
    :set0 100 ; low-priority set clause
    :from 110
    :join 120
@@ -612,6 +613,9 @@
 (defmethod format-clause :columns [[_ fields] _]
   (str "(" (comma-join (map to-sql fields)) ")"))
 
+(defmethod format-clause :composite [[_ fields] _]
+  (comma-join (map to-sql fields)))
+
 (defmethod format-clause :values [[_ values] _]
   (if (sequential? (first values))
     (str "VALUES " (comma-join (for [x values]

src/honeysql/helpers.cljc

@@ -250,6 +250,12 @@
     (check-varargs :merge-columns fields)
     (build-clause :merge-columns m fields)))
 
+(macros/usetime
+ (defhelper composite [m ms]
+   (if (nil? ms)
+     m
+     (assoc m :composite (collify ms)))))
+
 (defmethod build-clause :values [_ m vs]
   (assoc m :values vs))