diff --git a/README.md b/README.md
index 6f9d441..11e59e4 100644
--- a/README.md
+++ b/README.md
@@ -23,7 +23,9 @@ README readability; honeysql does not generate pretty-printed SQL.
 ## Usage
 
 ```clojure
+(refer-clojure :exclude '[for group-by set update])
 (require '[honey.sql :as sql]
+         ;; caution: this overwrites for, group-by, set, and update
          '[honey.sql.helpers :refer :all :as helpers])
 ```
 
@@ -407,22 +409,38 @@ Valid `:dialect` options are `:ansi` (the default, use this for PostgreSQL),
 
 #### Locking
 
-_This is not implemented yet._
+The ANSI/PostgreSQL/SQLServer dialects support locking selects via a `FOR` clause as follows:
 
-To issue a locking select, add a `:lock` to the query or use the lock helper. The lock value must be a map with a `:mode` value. The built-in
-modes are the standard `:update` (FOR UPDATE) or the vendor-specific `:mysql-share` (LOCK IN SHARE MODE) or `:postresql-share` (FOR SHARE). The
-lock map may also provide a `:wait` value, which if false will append the NOWAIT parameter, supported by PostgreSQL.
+* `:for [<lock-strength> <table(s)> <nowait>]` where `<lock-strength>` is required and may be one of:
+  * `:update`
+  * `:no-key-update`
+  * `:share`
+  * `:key-share`
+* Both `<table(s)>` and `<nowait>` are optional but if present, `<table(s)>` must either be:
+  * a single table name (as a keyword) or
+  * a sequence of table names (as keywords)
+* `<nowait>` must be `:nowait` if it is present.
+
+If `<table(s)>` and `<nowait>` are both omitted, you may also omit the `[`..`]` and just say `:for :update` etc.
 
 ```clojure
 (-> (select :foo.a)
     (from :foo)
     (where [:= :foo.a "baz"])
-    (lock :mode :update)
-    (sql/format))
-=> ["SELECT foo.a FROM foo WHERE foo.a = ? FOR UPDATE" "baz"]
+    (for :update)
+    (format))
+=> ["SELECT foo.a FROM foo WHERE (foo.a = ?) FOR UPDATE" "baz"]
 ```
 
-To support novel lock modes, implement the `format-lock-clause` multimethod.
+If the `:mysql` dialect is selected, an additional locking clause is available:
+`:lock :in-share-mode`.
+```clojure
+(sql/format {:select [:*] :from :foo
+             :where [:= :name [:inline "Jones"]]
+             :lock [:in-share-mode]}
+            {:dialect :mysql :quoted false})
+=> ["SELECT * FROM foo WHERE name = 'Jones' LOCK IN SHARE MODE"]
+```
 
 To be able to use dashes in quoted names, you can pass ```:allow-dashed-names true``` as an argument to the ```format``` function.
 ```clojure
@@ -430,8 +448,8 @@ To be able to use dashes in quoted names, you can pass ```:allow-dashed-names tr
   {:select [:f.foo-id :f.foo-name]
    :from [[:foo-bar :f]]
    :where [:= :f.foo-id 12345]}
-  :allow-dashed-names? true
-  :quoting :ansi)
+  {:allow-dashed-names? true ; not implemented yet
+   :quoted true})
 => ["SELECT \"f\".\"foo-id\", \"f\".\"foo-name\" FROM \"foo-bar\" \"f\" WHERE \"f\".\"foo-id\" = ?" 12345]
 ```
 
@@ -443,7 +461,7 @@ Here's a big, complicated query. Note that Honey SQL makes no attempt to verify
 (def big-complicated-map
   (-> (select :f.* :b.baz :c.quux [:b.bla "bla-bla"]
               [[:now]] [[:raw "@x := 10"]])
-      (modifiers :distinct) ; this is not implemented yet
+      #_(modifiers :distinct) ; this is not implemented yet
       (from [:foo :f] [:baz :b])
       (join :draq [:= :f.b :draq.x])
       (left-join [:clod :c] [:= :f.a :c.d])
@@ -453,7 +471,7 @@ Here's a big, complicated query. Note that Honey SQL makes no attempt to verify
                [:< 1 2 3]
                [:in :f.e [1 [:param :param2] 3]]
                [:between :f.e 10 20]])
-      (group :f.a :c.e)
+      (group-by :f.a :c.e)
       (having [:< 0 :f.e])
       (order-by [:b.baz :desc] :c.quux [:f.a :nulls-first])
       (limit 50)
diff --git a/src/honey/sql.cljc b/src/honey/sql.cljc
index 138899c..c1b3ece 100644
--- a/src/honey/sql.cljc
+++ b/src/honey/sql.cljc
@@ -13,6 +13,7 @@
 
 ;; dynamic dialect handling for formatting
 
+(declare clause-format)
 (def ^:private default-clause-order
   "The (default) order for known clauses. Can have items added and removed."
   [:with :with-recursive :intersect :union :union-all :except :except-all
@@ -20,7 +21,7 @@
    :columns :composite :set :from
    :join :left-join :right-join :inner-join :outer-join :full-join
    :cross-join
-   :where :group-by :having :order-by :limit :offset :values
+   :where :group-by :having :order-by :limit :offset :for :values
    :on-conflict :on-constraint :do-nothing :do-update-set
    :returning])
 
@@ -44,10 +45,15 @@
   {:ansi      {:quote #(str \" % \")}
    :sqlserver {:quote #(str \[ % \])}
    :mysql     {:quote #(str \` % \`)
-               :clause-order-fn #(add-clause-before
-                                  (filterv (complement #{:set}) %)
-                                  :set
-                                  :where)}
+               :clause-order-fn (fn [order]
+                                  ;; :lock is like :for
+                                  (swap! clause-format assoc :lock
+                                         (get @clause-format :for))
+                                  ;; MySQL :set has different priority
+                                  ;; and :lock is between :for and :values
+                                  (-> (filterv (complement #{:set}) order)
+                                      (add-clause-before :set :where)
+                                      (add-clause-before :lock :values)))}
    :oracle    {:quote #(str \" % \") :as false}})
 
 ; should become defonce
@@ -256,6 +262,21 @@
                                     sqls
                                     dirs)))] params)))
 
+(defn- format-lock-strength [k xs]
+  (let [[strength tables nowait] (if (sequential? xs) xs [xs])]
+    [(str (sql-kw k) " " (sql-kw strength)
+          (when tables
+            (str
+              (cond (= :nowait tables)
+                    (str " NOWAIT")
+                    (sequential? tables)
+                    (str " OF "
+                         (str/join ", " (map #'format-entity tables)))
+                    :else
+                    (str " OF " (format-entity tables)))
+              (when nowait
+                (str " NOWAIT")))))]))
+
 (defn- format-values [k xs]
   (cond (sequential? (first xs))
         ;; [[1 2 3] [4 5 6]]
@@ -356,6 +377,7 @@
          :order-by       #'format-order-by
          :limit          #'format-on-expr
          :offset         #'format-on-expr
+         :for            #'format-lock-strength
          :values         #'format-values
          :on-conflict    #'format-on-conflict
          :on-constraint  #'format-selector
@@ -381,7 +403,7 @@
    ;:delete-from 80
    ;:truncate 85
    ;:columns 90
-   :composite 95
+   ;:composite 95
    ;; no longer needed/supported :set0 100 ; low-priority set clause
    ;:from 110
    ;:join 120
diff --git a/src/honey/sql/helpers.cljc b/src/honey/sql/helpers.cljc
index dd2ed59..c78ed1a 100644
--- a/src/honey/sql/helpers.cljc
+++ b/src/honey/sql/helpers.cljc
@@ -2,7 +2,7 @@
 
 (ns honey.sql.helpers
   "Helper functions for the built-in clauses in honey.sql."
-  (:refer-clojure :exclude [update set group-by])
+  (:refer-clojure :exclude [update set group-by for])
   (:require [honey.sql :as h]))
 
 (defn- default-merge [current args]
@@ -56,6 +56,7 @@
 (defn order-by [& args] (generic :order-by args))
 (defn limit [& args] (generic :limit args))
 (defn offset [& args] (generic :offset args))
+(defn for [& args] (generic :for args))
 (defn values [& args] (generic :values args))
 (defn on-conflict [& args] (generic :on-conflict args))
 (defn on-constraint [& args] (generic :on-constraint args))
diff --git a/src/readme.clj b/src/readme.clj
index f9f7e46..0da2a2d 100644
--- a/src/readme.clj
+++ b/src/readme.clj
@@ -23,13 +23,15 @@
 
 
 (seancorfield.readme/defreadme readme-25
+(refer-clojure :exclude '[for group-by set update])
 (require '[honey.sql :as sql]
+         ;; caution: this overwrites for, group-by, set, and update
          '[honey.sql.helpers :refer :all :as helpers])
 )
 
 
 
-(seancorfield.readme/defreadme readme-32
+(seancorfield.readme/defreadme readme-34
 (def sqlmap {:select [:a :b :c]
              :from   [:foo]
              :where  [:= :f.a "baz"]})
@@ -41,7 +43,7 @@
 
 
 
-(seancorfield.readme/defreadme readme-44
+(seancorfield.readme/defreadme readme-46
 (sql/format sqlmap)
 => ["SELECT a, b, c FROM foo WHERE f.a = ?" "baz"]
 )
@@ -62,7 +64,7 @@
 
 
 
-(seancorfield.readme/defreadme readme-65
+(seancorfield.readme/defreadme readme-67
 (def q-sqlmap {:select [:foo/a :foo/b :foo/c]
                :from   [:foo]
                :where  [:= :foo/a "baz"]})
@@ -76,7 +78,7 @@
 
 
 
-(seancorfield.readme/defreadme readme-79
+(seancorfield.readme/defreadme readme-81
 (-> (select :a :b :c)
     (from :foo)
     (where [:= :f.a "baz"]))
@@ -84,7 +86,7 @@
 
 
 
-(seancorfield.readme/defreadme readme-87
+(seancorfield.readme/defreadme readme-89
 (= (-> (select :*) (from :foo))
    (-> (from :foo) (select :*)))
 => true
@@ -92,14 +94,14 @@
 
 
 
-(seancorfield.readme/defreadme readme-95
+(seancorfield.readme/defreadme readme-97
 (-> sqlmap (select :d))
 => '{:from [:foo], :where [:= :f.a "baz"], :select [:a :b :c :d]}
 )
 
 
 
-(seancorfield.readme/defreadme readme-102
+(seancorfield.readme/defreadme readme-104
 (-> sqlmap
     (dissoc :select)
     (select :*)
@@ -110,7 +112,7 @@
 
 
 
-(seancorfield.readme/defreadme readme-113
+(seancorfield.readme/defreadme readme-115
 (-> (select :*)
     (from :foo)
     (where [:= :a 1] [:< :b 100])
@@ -121,7 +123,7 @@
 
 
 
-(seancorfield.readme/defreadme readme-124
+(seancorfield.readme/defreadme readme-126
 (-> (select :a [:b :bar] :c [:d :x])
     (from [:foo :quux])
     (where [:= :quux.a 1] [:< :bar 100])
@@ -138,7 +140,7 @@
 
 
 
-(seancorfield.readme/defreadme readme-141
+(seancorfield.readme/defreadme readme-143
 (-> (insert-into :properties)
     (columns :name :surname :age)
     (values
@@ -157,7 +159,7 @@ VALUES (?, ?, ?), (?, ?, ?), (?, ?, ?)
 
 
 
-(seancorfield.readme/defreadme readme-160
+(seancorfield.readme/defreadme readme-162
 (-> (insert-into :properties)
     (values [{:name "John" :surname "Smith" :age 34}
              {:name "Andrew" :surname "Cooper" :age 12}
@@ -176,7 +178,7 @@ VALUES (?, ?, ?), (?, ?, ?), (?, ?, ?)
 
 
 
-(seancorfield.readme/defreadme readme-179
+(seancorfield.readme/defreadme readme-181
 (let [user-id 12345
       role-name "user"]
   (-> (insert-into :user_profile_to_role)
@@ -194,7 +196,7 @@ VALUES (?, (SELECT id FROM role WHERE name = ?))
 "user"]
 )
 
-(seancorfield.readme/defreadme readme-197
+(seancorfield.readme/defreadme readme-199
 (-> (select :*)
     (from :foo)
     (where [:in :foo.a (-> (select :a) (from :bar))])
@@ -206,7 +208,7 @@ VALUES (?, (SELECT id FROM role WHERE name = ?))
 
 
 
-(seancorfield.readme/defreadme readme-209
+(seancorfield.readme/defreadme readme-211
 (-> (insert-into :comp_table)
     (columns :name :comp_column)
     (values
@@ -224,7 +226,7 @@ VALUES (?, (?, ?)), (?, (?, ?))
 
 
 
-(seancorfield.readme/defreadme readme-227
+(seancorfield.readme/defreadme readme-229
 (-> (helpers/update :films)
     (set {:kind "dramatic"
            :watched [:+ :watched 1]})
@@ -250,7 +252,7 @@ WHERE kind = ?
 
 
 
-(seancorfield.readme/defreadme readme-253
+(seancorfield.readme/defreadme readme-255
 (-> (delete-from :films)
     (where [:<> :kind "musical"])
     (sql/format))
@@ -259,7 +261,7 @@ WHERE kind = ?
 
 
 
-(seancorfield.readme/defreadme readme-262
+(seancorfield.readme/defreadme readme-264
 (-> (delete [:films :directors])
     (from :films)
     (join :directors [:= :films.director_id :directors.id])
@@ -276,7 +278,7 @@ WHERE kind <> ?
 
 
 
-(seancorfield.readme/defreadme readme-279
+(seancorfield.readme/defreadme readme-281
 (-> (truncate :films)
     (sql/format))
 => ["TRUNCATE films"]
@@ -286,7 +288,7 @@ WHERE kind <> ?
 
 
 
-(seancorfield.readme/defreadme readme-289
+(seancorfield.readme/defreadme readme-291
 (sql/format {:union [(-> (select :*) (from :foo))
                      (-> (select :*) (from :bar))]})
 => ["SELECT * FROM foo UNION SELECT * FROM bar"]
@@ -296,11 +298,11 @@ WHERE kind <> ?
 
 
 
-(seancorfield.readme/defreadme readme-299
+(seancorfield.readme/defreadme readme-301
 (-> (select :%count.*) (from :foo) sql/format)
 => ["SELECT count(*) FROM foo"]
 )
-(seancorfield.readme/defreadme readme-303
+(seancorfield.readme/defreadme readme-305
 (-> (select :%max.id) (from :foo) sql/format)
 => ["SELECT max(id) FROM foo"]
 )
@@ -311,7 +313,7 @@ WHERE kind <> ?
 
 
 
-(seancorfield.readme/defreadme readme-314
+(seancorfield.readme/defreadme readme-316
 (-> (select :id)
     (from :foo)
     (where [:= :a :?baz])
@@ -324,19 +326,19 @@ WHERE kind <> ?
 
 
 
-(seancorfield.readme/defreadme readme-327
+(seancorfield.readme/defreadme readme-329
 (def call-qualify-map
   (-> (select [[:foo :bar]] [[:raw "@var := foo.bar"]])
       (from :foo)
       (where [:= :a [:param :baz]] [:= :b [:inline 42]])))
 )
-(seancorfield.readme/defreadme readme-333
+(seancorfield.readme/defreadme readme-335
 call-qualify-map
 => '{:where [:and [:= :a [:param :baz]] [:= :b [:inline 42]]]
      :from (:foo)
      :select [[[:foo :bar]] [[:raw "@var := foo.bar"]]]}
 )
-(seancorfield.readme/defreadme readme-339
+(seancorfield.readme/defreadme readme-341
 (sql/format call-qualify-map {:params {:baz "BAZ"}})
 => ["SELECT foo(bar), @var := foo.bar FROM foo WHERE (a = ?) AND (b = 42)" "BAZ"]
 )
@@ -346,7 +348,7 @@ call-qualify-map
 
 
 
-(seancorfield.readme/defreadme readme-349
+(seancorfield.readme/defreadme readme-351
 (-> (insert-into :sample)
     (values [{:location [:ST_SetSRID
                          [:ST_MakePoint 0.291 32.621]
@@ -372,7 +374,7 @@ VALUES (ST_SetSRID(ST_MakePoint(?, ?), CAST(? AS integer)))
 
 
 
-(seancorfield.readme/defreadme readme-375
+(seancorfield.readme/defreadme readme-377
 (-> (select :*)
     (from :foo)
     (where [:< :expired_at [:raw ["now() - '" 5 " seconds'"]]])
@@ -380,7 +382,7 @@ VALUES (ST_SetSRID(ST_MakePoint(?, ?), CAST(? AS integer)))
 => ["SELECT * FROM foo WHERE expired_at < now() - '? seconds'" 5]
 )
 
-(seancorfield.readme/defreadme readme-383
+(seancorfield.readme/defreadme readme-385
 (-> (select :*)
     (from :foo)
     (where [:< :expired_at [:raw ["now() - '" [:param :t] " seconds'"]]])
@@ -397,7 +399,7 @@ VALUES (ST_SetSRID(ST_MakePoint(?, ?), CAST(? AS integer)))
 
 
 
-(seancorfield.readme/defreadme readme-400
+(seancorfield.readme/defreadme readme-402
 (-> (select :foo.a)
     (from :foo)
     (where [:= :foo.a "baz"])
@@ -413,25 +415,43 @@ VALUES (ST_SetSRID(ST_MakePoint(?, ?), CAST(? AS integer)))
 
 
 
-(seancorfield.readme/defreadme readme-416
-(-> (select :foo.a)
-    (from :foo)
-    (where [:= :foo.a "baz"])
-    (lock :mode :update)
-    (sql/format))
-=> ["SELECT foo.a FROM foo WHERE foo.a = ? FOR UPDATE" "baz"]
-)
+
+
+
+
+
+
 
 
 
 
 (seancorfield.readme/defreadme readme-428
+(sql/format {:select [:*] :from :foo
+             :where [:= :name [:inline "Jones"]]
+             :lock [:in-share-mode]}
+            {:dialect :mysql :quoted false})
+=> ["SELECT * FROM foo WHERE name = 'Jones' LOCK IN SHARE MODE"]
+)
+
+(seancorfield.readme/defreadme readme-436
+(-> (select :foo.a)
+    (from :foo)
+    (where [:= :foo.a "baz"])
+    (for :update)
+    (format))
+=> ["SELECT foo.a FROM foo WHERE (foo.a = ?) FOR UPDATE" "baz"]
+)
+
+
+
+
+(seancorfield.readme/defreadme readme-448
 (sql/format
   {:select [:f.foo-id :f.foo-name]
    :from [[:foo-bar :f]]
    :where [:= :f.foo-id 12345]}
-  :allow-dashed-names? true
-  :quoting :ansi)
+  {:allow-dashed-names? true ; not implemented yet
+   :quoted true})
 => ["SELECT \"f\".\"foo-id\", \"f\".\"foo-name\" FROM \"foo-bar\" \"f\" WHERE \"f\".\"foo-id\" = ?" 12345]
 )
 
@@ -439,11 +459,11 @@ VALUES (ST_SetSRID(ST_MakePoint(?, ?), CAST(? AS integer)))
 
 
 
-(seancorfield.readme/defreadme readme-442
+(seancorfield.readme/defreadme readme-462
 (def big-complicated-map
   (-> (select :f.* :b.baz :c.quux [:b.bla "bla-bla"]
               [[:now]] [[:raw "@x := 10"]])
-      (modifiers :distinct) ; this is not implemented yet
+      #_(modifiers :distinct) ; this is not implemented yet
       (from [:foo :f] [:baz :b])
       (join :draq [:= :f.b :draq.x])
       (left-join [:clod :c] [:= :f.a :c.d])
@@ -453,13 +473,13 @@ VALUES (ST_SetSRID(ST_MakePoint(?, ?), CAST(? AS integer)))
                [:< 1 2 3]
                [:in :f.e [1 [:param :param2] 3]]
                [:between :f.e 10 20]])
-      (group :f.a :c.e)
+      (group-by :f.a :c.e)
       (having [:< 0 :f.e])
       (order-by [:b.baz :desc] :c.quux [:f.a :nulls-first])
       (limit 50)
       (offset 10)))
 )
-(seancorfield.readme/defreadme readme-462
+(seancorfield.readme/defreadme readme-482
 big-complicated-map
 => {:select [:f.* :b.baz :c.quux [:b.bla "bla-bla"]
              [[:now]] [[:raw "@x := 10"]]]
@@ -479,7 +499,7 @@ big-complicated-map
     :limit 50
     :offset 10}
 )
-(seancorfield.readme/defreadme readme-482
+(seancorfield.readme/defreadme readme-502
 (sql/format big-complicated-map {:param1 "gabba" :param2 2})
 => ["
 SELECT DISTINCT f.*, b.baz, c.quux, b.bla AS bla_bla, now(), @x := 10
@@ -496,7 +516,7 @@ OFFSET ?
 "
 "bort" "gabba" 1 2 2 3 1 2 3 10 20 0 50 10]
 )
-(seancorfield.readme/defreadme readme-499
+(seancorfield.readme/defreadme readme-519
 ;; Printable and readable
 (= big-complicated-map (read-string (pr-str big-complicated-map)))
 => true
@@ -508,7 +528,7 @@ OFFSET ?
 
 
 
-(seancorfield.readme/defreadme readme-511
+(seancorfield.readme/defreadme readme-531
 (defmethod fmt/fn-handler "betwixt" [_ field lower upper]
   (str (fmt/to-sql field) " BETWIXT "
        (fmt/to-sql lower) " AND " (fmt/to-sql upper)))
@@ -519,23 +539,23 @@ OFFSET ?
 
 
 
-(seancorfield.readme/defreadme readme-522
+(seancorfield.readme/defreadme readme-542
 ;; Takes a MapEntry of the operator & clause data, plus the entire SQL map
 (defmethod fmt/format-clause :foobar [[op v] sqlmap]
   (str "FOOBAR " (fmt/to-sql v)))
 )
-(seancorfield.readme/defreadme readme-527
+(seancorfield.readme/defreadme readme-547
 (sql/format {:select [:a :b] :foobar :baz})
 => ["SELECT a, b FOOBAR baz"]
 )
-(seancorfield.readme/defreadme readme-531
+(seancorfield.readme/defreadme readme-551
 (require '[honeysql.helpers :refer [defhelper]])
 
 ;; Defines a helper function, and allows 'build' to recognize your clause
 (defhelper foobar [m args]
   (assoc m :foobar (first args)))
 )
-(seancorfield.readme/defreadme readme-538
+(seancorfield.readme/defreadme readme-558
 (-> (select :a :b) (foobar :baz) sql/format)
 => ["SELECT a, b FOOBAR baz"]
 
@@ -543,7 +563,7 @@ OFFSET ?
 
 
 
-(seancorfield.readme/defreadme readme-546
+(seancorfield.readme/defreadme readme-566
 (fmt/register-clause! :foobar 110)
 )
 
diff --git a/test/honey/sql/helpers_test.cljc b/test/honey/sql/helpers_test.cljc
new file mode 100644
index 0000000..2c37b4a
--- /dev/null
+++ b/test/honey/sql/helpers_test.cljc
@@ -0,0 +1,6 @@
+;; copyright (c) sean corfield, all rights reserved
+
+(ns honey.sql.helpers-test
+  (:require #?(:clj [clojure.test :refer [deftest is testing]]
+               :cljs [cljs.test :refer-macros [deftest is testing]])
+            [honey.sql.helpers :as sut]))
diff --git a/test/honey/sql_test.cljc b/test/honey/sql_test.cljc
index 8071fb1..915e4a4 100644
--- a/test/honey/sql_test.cljc
+++ b/test/honey/sql_test.cljc
@@ -402,6 +402,46 @@
                   :from [[:foo :f]]
                   :cross-join [[:bar :b]]}))))
 
+(deftest locking-select-tests
+  (testing "PostgreSQL/ANSI FOR"
+    (is (= ["SELECT * FROM foo FOR UPDATE"]
+           (format {:select [:*] :from :foo :for :update})))
+    (is (= ["SELECT * FROM foo FOR NO KEY UPDATE"]
+           (format {:select [:*] :from :foo :for :no-key-update})))
+    (is (= ["SELECT * FROM foo FOR SHARE"]
+           (format {:select [:*] :from :foo :for :share})))
+    (is (= ["SELECT * FROM foo FOR KEY SHARE"]
+           (format {:select [:*] :from :foo :for :key-share})))
+    (is (= ["SELECT * FROM foo FOR UPDATE"]
+           (format {:select [:*] :from :foo :for [:update]})))
+    (is (= ["SELECT * FROM foo FOR NO KEY UPDATE"]
+           (format {:select [:*] :from :foo :for [:no-key-update]})))
+    (is (= ["SELECT * FROM foo FOR SHARE"]
+           (format {:select [:*] :from :foo :for [:share]})))
+    (is (= ["SELECT * FROM foo FOR KEY SHARE"]
+           (format {:select [:*] :from :foo :for [:key-share]})))
+    (is (= ["SELECT * FROM foo FOR UPDATE NOWAIT"]
+           (format {:select [:*] :from :foo :for [:update :nowait]})))
+    (is (= ["SELECT * FROM foo FOR UPDATE OF bar NOWAIT"]
+           (format {:select [:*] :from :foo :for [:update :bar :nowait]})))
+    (is (= ["SELECT * FROM foo FOR UPDATE OF bar, quux"]
+           (format {:select [:*] :from :foo :for [:update [:bar :quux]]}))))
+  (testing "MySQL for/lock"
+    ;; these examples come from:
+    (is (= ["SELECT * FROM t1 WHERE c1 = (SELECT c1 FROM t2) FOR UPDATE"] ; portable
+           (format {:select [:*] :from :t1
+                    :where [:= :c1 {:select [:c1] :from :t2}]
+                    :for [:update]})))
+    (is (= ["SELECT * FROM t1 WHERE c1 = (SELECT c1 FROM t2 FOR UPDATE) FOR UPDATE"]
+           (format {:select [:*] :from :t1
+                    :where [:= :c1 {:select [:c1] :from :t2 :for [:update]}]
+                    :for [:update]})))
+    (is (= ["SELECT * FROM foo WHERE name = 'Jones' LOCK IN SHARE MODE"] ; MySQL-specific
+           (format {:select [:*] :from :foo
+                    :where [:= :name [:inline "Jones"]]
+                    :lock [:in-share-mode]}
+                   {:dialect :mysql :quoted false})))))
+
 (deftest insert-example-tests
   ;; these examples are taken from https://www.postgresql.org/docs/13/sql-insert.html
   (is (= ["