Document more clauses

doc/clause-reference.md

@@ -61,25 +61,173 @@ user=> (sql/format {:with [[:stuff {:columns [:id :name]}]
 > Note: HoneySQL 0.6.2 introduced support for CTEs a long time ago and it expected the pair (of result set and query) to be wrapped in a sequence, even though you can only have a single CTE. For backward compatibility, HoneySQL 2.0 accepts that format but it should be considered deprecated.
 
 ## intersect, union, union-all, except, except-all
+
+These all expect a sequence of SQL clauses, those clauses
+will be wrapped in parentheses, and the SQL keyword interspersed
+between those clauses.
+
+```clojure
+user=> (sql/format '{union [{select (id,status) from (table-a)}
+                            {select (id,(event status) from (table-b))}]})
+["(SELECT id, status FROM table_a) UNION (SELECT id, event AS status, from, table_b)"]
+```
+
 ## select, select-distinct
+
+`:select` expects a sequence of SQL entities (column names
+or expressions). Any of the SQL entities can be a pair of entity and alias. If you are selecting an expression, you would most
+often provide an alias for the expression, but it can be omitted
+as in the following:
+
+```clojure
+user=> (sql/format '{select (id, ((* cost 2)), (event status))
+                     from (table)})
+["SELECT id, cost * ?, event AS status FROM table" 2]
+```
+
+With an alias on the expression:
+
+```clojure
+user=> (sql/format {:select [:id, [[:* :cost 2] :total], [:event :status]]
+                    :from [:table]})
+["SELECT id, cost * ? AS total, event AS status FROM table" 2]
+```
+
+`:select-distinct` works the same way but produces `SELECT DISTINCT`.
+
 ## insert-into
+
+There are two use cases with `:insert-into`. The first case
+takes just a simple SQL entity (the table name). The more
+complex case takes a pair of a SQL entity and a SQL query.
+In that second case, you can specify the columns by using
+a pair of the table name and a sequence of column names.
+
+For the first case, you'll use the `:values` clause and you
+may use the `:columns` clause as well.
+
+```clojure
+user=> (sql/format {:insert-into :transport
+                    :values [[1 "Car"] [2 "Boat"] [3 "Bike"]]})
+["INSERT INTO transport VALUES (?, ?), (?, ?), (?, ?)" 1 "Car" 2 "Boat" 3 "Bike"]
+user=> (sql/format {:insert-into :transport
+                    :columns [:id :name]
+                    :values [[1 "Car"] [2 "Boat"] [3 "Bike"]]})
+["INSERT INTO transport (id, name) VALUES (?, ?), (?, ?), (?, ?)" 1 "Car" 2 "Boat" 3 "Bike"]
+```
+
+The second case:
+
+```clojure
+user=> (sql/format '{insert-into (transport {select (id, name) from (cars)})})
+["INSERT INTO transport SELECT id, name FROM cars"]
+user=> (sql/format '{insert-into ((transport (id, name)) {select (*) from (cars)})})
+["INSERT INTO transport (id, name) SELECT * FROM cars"]
+```
+
 ## update
+
+`:update` expects either a simple SQL entity (table name)
+or a pair of the table name and an alias:
+
+```clojure
+user=> (sql/format {:update :transport
+                    :set {:name "Yacht"}
+                    :where [:= :id 2]})
+["UPDATE transport SET name = ? WHERE id = ?" "Yacht" 2]
+```
+
 ## delete, delete-from
+
+`:delete-from` is the simple use case here, accepting just a
+SQL entity (table name). `:delete` allows for deleting from
+multiple tables, accepting a sequence of either table names
+or aliases:
+
+```clojure
+user=> (sql/format '{delete-from transport where (= id 1)})
+["DELETE FROM transport WHERE id = ?" 1]
+user=> (sql/format {:delete [:order :item]
+                    :from [:order]
+                    :join [:item [:= :order.item-id :item.id]]
+                    :where [:= :item.id 42]})
+["DELETE order, item FROM order INNER JOIN item ON order.item_id = item.id WHERE item.id = ?" 42]
+```
+
 ## truncate
+
+`:truncate` accepts a simple SQL entity (table name):
+
+```clojure
+user=> (sql/format '{truncate transport})
+["TRUNCATE transport"]
+```
+
 ## columns
+
+Wherever you need just a list of column names `:columns`
+accepts a sequence of SQL entities (names). We saw an
+example above with `:insert-into`.
+
 ## set (ANSI)
+
+`:set` accepts a hash map of SQL entities and the values
+that they should be assigned. This precedence -- between
+`:columns` and `:from` -- corresponds to ANSI SQL which
+is correct for most databases. The MySQL dialect that
+HoneySQL 2.0 supports has a different precedence (below).
+
+```clojure
+user=> (sql/format {:update :order
+                    :set {:line-count [:+ :line-count 1]}
+                    :where [:= :item-id 42]})
+["UPDATE order SET line_count = line_count + ? WHERE item_id = ?" 1 42]
+```
+
 ## from
+
+`:from` accepts a single sequence argument that lists
+one or more SQL entities. Each entity can either be a
+simple table name (keyword or symbol) or a pair of a
+table name and an alias:
+
+```clojure
+user=> (sql/format {:select [:username :name]
+                    :from [:user :status]
+                    :where [:and [:= :user.statusid :status.id]
+                                 [:= :user.id 9]]})
+["SELECT username, name FROM user, status WHERE (user.statusid = status.id) AND (user.id = ?)" 9]
+user=> (sql/format {:select [:u.username :s.name]
+                    :from [[:user :u] [:status :s]]
+                    :where [:and [:= :u.statusid :s.id]
+                                 [:= :u.id 9]]})
+["SELECT u.username, s.name FROM user AS u, status AS s WHERE (u.statusid = s.id) AND (u.id = ?)" 9]
+```
+
 ## using
+
 ## join, left-join, right-join, inner-join, outer-join, full-join
+
 ## cross-join
+
 ## set (MySQL)
+
 ## where
+
 ## group-by
+
 ## having
+
 ## order-by
+
 ## limit, offset (MySQL)
+
 ## for
+
 ## lock (MySQL)
+
 ## values
+
 ## on-conflict, on-constraint, do-nothing, do-update-set
+
 ## returning

src/honey/sql/helpers.cljc

@@ -44,8 +44,8 @@
     (assoc {} k data)))
 
 (defn nest [& args] (generic :nest args))
-(defn with [& args] (generic :with args))
+(defn with [& args] (generic-1 :with args))
-(defn with-recursive [& args] (generic :with-recursive args))
+(defn with-recursive [& args] (generic-1 :with-recursive args))
 ;; these five need to supply an empty hash map since they wrap
 ;; all of their arguments:
 (defn intersect [& args] (generic :intersect (cons {} args)))