SQL Clauses Supported

This section lists all the SQL clauses that HoneySQL supports out of the box, in the order that they are processed for formatting.

Clauses can be specified as keywords or symbols. Use - in the clause name where the formatted SQL would have a space (e.g., :left-join is formatted as LEFT JOIN).

Except as noted, these clauses apply to all the SQL dialects that HoneySQL supports.

alter-table, add-column, drop-column, modify-column, rename-column

:alter-table can accept either a single table name or a sequence that begins with a table name and is followed by clauses that manipulate columns (or indices, see below).

If a single table name is provided, a single column (or index) operation can provided in the hash map DSL:

user=> (sql/format {:alter-table :fruit
                    :add-column [:id :int [:not nil]]})
["ALTER TABLE fruit ADD COLUMN id INT NOT NULL"]
user=> (sql/format {:alter-table :fruit
                    :drop-column :ident})
["ALTER TABLE fruit DROP COLUMN ident"]
user=> (sql/format {:alter-table :fruit
                    :modify-column [:id :int :unsigned nil]})
["ALTER TABLE fruit MODIFY COLUMN id INT UNSIGNED NULL"]
user=> (sql/format {:alter-table :fruit
                    :rename-column [:look :appearance]})
["ALTER TABLE fruit RENAME COLUMN look TO appearance"]

If a sequence of a table name and various clauses is provided, the generated ALTER statement will have comma-separated clauses:

user=> (sql/format {:alter-table [:fruit
                                  {:add-column [:id :int [:not nil]]}
                                  {:drop-column :ident}]})
["ALTER TABLE fruit ADD COLUMN id INT NOT NULL, DROP COLUMN ident"]

As can be seen above, :add-column and :modify-column both accept a column description (as a sequence of simple expressions); :drop-column accepts a single column name, and :rename-column accepts a sequence with two column names: the "from" and the "to" names.

add-index, drop-index

Used with :alter-table, :add-index accepts a single (function) expression that describes an index, and :drop-index accepts a single index name:

user=> (sql/format {:alter-table :fruit
                    :add-index [:index :look :appearance]})
["ALTER TABLE fruit ADD INDEX look(appearance)"]
user=> (sql/format {:alter-table :fruit
                    :add-index [:unique nil :color :appearance]})
["ALTER TABLE fruit ADD UNIQUE(color,appearance)"]
user=> (sql/format {:alter-table :fruit :drop-index :look})
["ALTER TABLE fruit DROP INDEX look"]

rename-table

Used with :alter-table, :rename-table accepts a single table name:

user=> (sql/format {:alter-table :fruit :rename-table :vegetable})
["ALTER TABLE fruit RENAME TO vegetable"]

Note: this would be better as :rename-to since there is a RENAME TABLE old_name TO new_name SQL statement. [I may yet add a variant to support that specifically]

create-table, with-columns

:create-table can accept a single table name or a pair containing a table name and a flag indicating the creation should be conditional (:if-not-exists or the symbol if-not-exists, although any truthy value will work). :create-table should be used with :with-columns to specify the actual columns in the table:

user=> (sql/format {:create-table :fruit
                    :with-columns
                    [[:id :int [:not nil]]
                     [:name [:varchar 32] [:not nil]]
                     [:cost :float :null]]})
;; reformatted for clarity:
["CREATE TABLE fruit (
  id INT NOT NULL,
  name VARCHAR(32) NOT NULL,
  cost FLOAT NULL
)"]

The :with-columns clause is formatted as if {:inline true} was specified so nothing is parameterized. In addition, everything except the first element of a column description will be uppercased (mostly to give the appearance of separating the column name from the SQL keywords).

Various function-like expressions can be specified, as shown in the example above, but allow things like CHECK for a constraint, FOREIGN KEY (with a column name), REFERENCES (with a pair of column names). See Clause Descriptors in Special Syntax for more details.

create-view

:create-view accepts a single view name:

user=> (sql/format {:create-view :products
                    :select [:*]
                    :from [:items]
                    :where [:= :category "product"]})
["CREATE VIEW products AS SELECT * FROM items WHERE category = ?" "product"]

drop-table

:drop-table can accept a single table name or a sequence of table names. If a sequence is provided and the first element is :if-exists (or the symbol if-exists) then that conditional clause is added before the table names:

user=> (sql/format '{drop-table (if-exists foo bar)})
["DROP TABLE IF EXISTS foo, bar"]
user=> (sql/format {:drop-table [:foo :bar]})
["DROP TABLE foo, bar"]

nest

This is pseudo-syntax that lets you wrap a substatement in an extra level of parentheses. It should rarely be needed and it is mostly present to provide the same functionality for clauses that [:nest ..] provides for expressions.

with, with-recursive

These provide CTE support for SQL Server. The argument to :with (or :with-recursive) is a sequences of pairs, each of a result set name (or description) and a basic SQL statement. The result set can either be a SQL entity (a simple name) or a pair of a SQL entity and a set of column names.

user=> (sql/format '{with ((stuff {select (:*) from (foo)}),
                           (nonsense {select (:*) from (bar)}))
                     select (foo.id,bar.name)
                     from (stuff, nonsense)
                     where (= status 0)})
["WITH stuff AS (SELECT * FROM foo), nonsense AS (SELECT * FROM bar) SELECT foo.id, bar.name FROM stuff, nonsense WHERE status = ?" 0]

You can specify a list of columns for the CTE like this:

user=> (sql/format {:with [[[:stuff {:columns [:id :name]}]
                            {:select [:*] :from [:foo]}]]
                    :select [:id :name]
                    :from [:stuff]
                    :where [:= :status 0]})
["WITH stuff (id, name) AS (SELECT * FROM foo) SELECT id, name FROM stuff WHERE status = ?" 0]

You can use a VALUES clause in the CTE:

user=> (sql/format {:with [[[:stuff {:columns [:id :name]}]
                            {:values [[1 "Sean"] [2 "Jay"]]}]]
                    :select [:id :name]
                    :from [:stuff]})
["WITH stuff (id, name) AS (VALUES (?, ?), (?, ?)) SELECT id, name FROM stuff" 1 "Sean" 2 "Jay"]

:with-recursive follows the same rules as :with and produces WITH RECURSIVE instead of just WITH.

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.

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 and :select-distinct expect 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:

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:

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.

HoneySQL does not yet support SELECT .. INTO .. or SELECT .. BULK COLLECT INTO ...

select-distinct-on

Similar to :select-distinct above but the first element in the sequence should be a sequence of columns for the DISTINCT ON clause and the remaining elements are the columns to be selected:

user=> (sql/format '{select-distinct-on [[a b] c d]
                     from [table]})
["SELECT DISTINCT ON(a, b) c, d FROM table"]

insert-into

There are three use cases with :insert-into.

The first case takes just a table specifier (either a table name or a table/alias pair), and then you can optionally specify the columns (via a :columns clause).

The second case takes a pair of a table specifier (either a table name or table/alias pair) and a sequence of column names (so you do not need to also use :columns).

The third case takes a pair of either a table specifier or a table/column specifier and a SQL query.

For the first and second cases, you'll use the :values clause to specify rows of values to insert.

;; first case -- table specifier:
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"]
;; with an alias:
user=> (sql/format {:insert-into [:transport :t]
                    :values [[1 "Car"] [2 "Boat"] [3 "Bike"]]})
["INSERT INTO transport AS t VALUES (?, ?), (?, ?), (?, ?)" 1 "Car" 2 "Boat" 3 "Bike"]
user=> (sql/format {:insert-into [:transport :t]
                    :columns [:id :name]
                    :values [[1 "Car"] [2 "Boat"] [3 "Bike"]]})
["INSERT INTO transport AS t (id, name) VALUES (?, ?), (?, ?), (?, ?)" 1 "Car" 2 "Boat" 3 "Bike"]
;; second case -- table specifier and columns:
user=> (sql/format {:insert-into [:transport [:id :name]]
                    :values [[1 "Car"] [2 "Boat"] [3 "Bike"]]})
["INSERT INTO transport (id, name) VALUES (?, ?), (?, ?), (?, ?)" 1 "Car" 2 "Boat" 3 "Bike"]
;; with an alias:
user=> (sql/format {:insert-into [[:transport :t] [:id :name]]
                    :values [[1 "Car"] [2 "Boat"] [3 "Bike"]]})
["INSERT INTO transport AS t (id, name) VALUES (?, ?), (?, ?), (?, ?)" 1 "Car" 2 "Boat" 3 "Bike"]
;; third case -- table/column specifier and query:
user=> (sql/format '{insert-into (transport {select (id, name) from (cars)})})
["INSERT INTO transport SELECT id, name FROM cars"]
;; with columns:
user=> (sql/format '{insert-into ((transport (id, name)) {select (*) from (cars)})})
["INSERT INTO transport (id, name) SELECT * FROM cars"]
;; with an alias:
user=> (sql/format '{insert-into ((transport t) {select (id, name) from (cars)})})
["INSERT INTO transport AS t SELECT id, name FROM cars"]
;; with columns:
user=> (sql/format '{insert-into ((transport (id, name)) {select (*) from (cars)})})
["INSERT INTO transport (id, name) SELECT * FROM cars"]
;; with an alias and columns:
user=> (sql/format '{insert-into (((transport t) (id, name)) {select (*) from (cars)})})
["INSERT INTO transport AS t (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:

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:

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):

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).

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:

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]

Note: the actual formatting of a :from clause is currently identical to the formatting of a :select clause.

using

:using 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.

:using is intended to be used as a simple join with a :delete-from clause (see PostgreSQL DELETE statement for more detail).

Note: the actual formatting of a :using clause is currently identical to the formatting of a :select clause.

join, left-join, right-join, inner-join, outer-join, full-join

All these join clauses have the same structure: they accept a sequence of alternating SQL entities (table names) and conditions that specify how to perform the join. The table names can either be simple names or a pair of a table name and an alias:

user=> (sql/format {:select [:u.username :s.name]
                    :from [[:user :u]]
                    :join [[:status :s] [:= :u.statusid :s.id]]
                    :where [:= :s.id 2]})
["SELECT u.username, s.name FROM user AS u INNER JOIN status AS s ON u.statusid = s.id WHERE s.id = ?" 2]

An alternative to a join condition is a USING expression:

user=> (sql/format {:select [:t.ref :pp.code]
                    :from [[:transaction :t]]
                    :left-join [[:paypal-tx :pp]
                                [:using :id]]
                    :where [:= "settled" :pp.status]})
["SELECT t.ref, pp.code FROM transaction AS t LEFT JOIN paypal_tx AS pp USING (id) WHERE ? = pp.status" "settled"]

cross-join

:cross-join 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.

Note: the actual formatting of a :cross-join clause is currently identical to the formatting of a :select clause.

set (MySQL)

This is the precedence of the :set clause for the MySQL dialect. It is otherwise identical to the :set clause described above.

where

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.

group-by

:group-by accepts a sequence of one or more SQL expressions.

user=> (sql/format '{select (*) from (table)
                     group-by (status, (year created-date))})
["SELECT * FROM table GROUP BY status, YEAR(created_date)"]

having

The :having clause works identically to :where above but is rendered into the SQL later in precedence order.

window, partition-by (and over)

:window accepts a pair of SQL entity (the window name) and the window "function" as a SQL clause (a hash map).

:partition-by accepts the same arguments as :select above (even though the allowable SQL generated is much more restrictive).

These are expected to be used with the :over expression (special syntax).

user=> (sql/format {:select [:id
                             [[:over
                               [[:avg :salary]
                                {:partition-by [:department]
                                 :order-by [:designation]}
                                :Average]
                               [[:max :salary]
                                :w
                                :MaxSalary]]]]
                    :from [:employee]
                    :window [:w {:partition-by [:department]}]})
["SELECT id, AVG(salary) OVER (PARTITION BY department ORDER BY designation ASC) AS Average, MAX(salary) OVER w AS MaxSalary FROM employee WINDOW w AS (PARTITION BY department)"]
;; easier to write with helpers (and easier to read!):
user=> (sql/format (-> (select :id
                               (over [[:avg :salary] (-> (partition-by :department) (order-by :designation)) :Average]
                                     [[:max :salary] :w :MaxSalary]))
                       (from :employee)
                       (window :w (partition-by :department))))
["SELECT id, AVG(salary) OVER (PARTITION BY department ORDER BY designation ASC) AS Average, MAX(salary) OVER w AS MaxSalary FROM employee WINDOW w AS (PARTITION BY department)"]

The window function in the :over expression may be {} or nil:

user=> (sql/format {:select [:id
                             [[:over
                               [[:avg :salary]
                                {}
                                :Average]
                               [[:max :salary]
                                nil
                                :MaxSalary]]]]
                    :from [:employee]})
["SELECT id, AVG(salary) OVER () AS Average, MAX(salary) OVER () AS MaxSalary FROM employee"]
;; easier to write with helpers (and easier to read!):
user=> (sql/format (-> (select :id
                               (over [[:avg :salary] {} :Average]
                                     [[:max :salary] nil :MaxSalary]))
                       (from :employee)))
["SELECT id, AVG(salary) OVER () AS Average, MAX(salary) OVER () AS MaxSalary FROM employee"]

order-by

:order-by accepts a sequence of one 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 or :desc -- or the symbol equivalent).

If you want to order by an expression, you should wrap it as a pair with a direction:

user=> (sql/format '{select (*) from table
                     ;; simple orderings:
                     order-by (status, created-date)})
["SELECT * FROM table ORDER BY status ASC, created_date ASC"]
user=> (sql/format '{select (*) from table
                     ;; explicit direction provided:
                     order-by ((status asc), ((year created-date) asc))})
["SELECT * FROM table ORDER BY status ASC, YEAR(created_date) ASC"]

The default direction is ascending and if you provide a wrapped expression you can omit the direction if you want:

user=> (sql/format {:select [:*] :from :table
                    ;; expression without direction is still wrapped:
                    :order-by [:status, [[:year :created-date]]]})
["SELECT * FROM table ORDER BY status ASC, YEAR(created_date) ASC"]

limit, offset (MySQL)

Both :limit and :offset expect a single SQL expression:

user=> (sql/format {:select [:id :name]
                    :from [:table]
                    :limit 20 :offset 20})
["SELECT id, name FROM table LIMIT ? OFFSET ?" 20 20]

Note: In the prerelease, these MySQL-specific clauses are in the default dialect but these will be moved to the :mysql dialect.

for

The :for clause accepts either a single item -- the lock strength -- or a sequence of up to three items of which the first is the lock strength, followed by an optional table name (or sequence of table names), followed by how to deal with the lock:

user=> (sql/format '{select (*) from (table)
                     for update})
["SELECT * FROM table FOR UPDATE"]
user=> (sql/format '{select (*) from (table)
                     for no-key-update})
["SELECT * FROM table FOR NO KEY UPDATE"]
user=> (sql/format '{select (*) from (table)
                     for (key-share wait)})
["SELECT * FROM table FOR KEY SHARE WAIT"]
user=> (sql/format '{select (*) from (table)
                     for (update bar wait)})
["SELECT * FROM table FOR UPDATE OF bar WAIT"]
user=> (sql/format '{select (*) from (table)
                     for (update (bar quux) wait)})
["SELECT * FROM table FOR UPDATE OF bar, quux WAIT"]

The lock strength can be any SQL keyword or phrase represented as a Clojure keyword (or symbol), with spaces represented by -.

The three SQL keywords/phrases that are recognized as not being a table name in the second slot are NOWAIT, SKIP LOCKED, and WAIT.

However, in the case where a table name (or sequence of table names) is present, no check is made on the keyword or phrase in that third slot (although it is expected to be just one of those three mentioned above).

lock (MySQL)

The syntax accepted for MySQL's :lock is exactly the same as the :for clause above.

Note: In the prerelease, this MySQL-specific clauses is in the default dialect but this will be moved to the :mysql dialect.

values

:values accepts either a sequence of hash maps representing row values or a sequence of sequences, also representing row values.

In the former case, all of the rows are augmented to have nil values for any missing keys (columns). In the latter, all of the rows are padded to the same length by adding nil values if needed.

user=> (sql/format {:insert-into :table
                    :values [[1 2] [2 3 4 5] [3 4 5]]})
["INSERT INTO table VALUES (?, ?, NULL, NULL), (?, ?, ?, ?), (?, ?, ?, NULL)" 1 2 2 3 4 5 3 4 5]
user=> (sql/format '{insert-into table
                     values ({id 1 name "Sean"}
                             {id 2}
                             {name "Extra"})})
["INSERT INTO table (id, name) VALUES (?, ?), (?, NULL), (NULL, ?)" 1 "Sean" 2 "Extra"]

on-conflict, on-constraint, do-nothing, do-update-set

These are grouped together because they are handled as if they are separate clauses but they will appear in pairs: ON ... DO ....

:on-conflict accepts either a single SQL entity (a keyword or symbol), or a SQL clause, or a pair of a SQL entity and a SQL clause. The SQL entity is a column name and the SQL clause can be an :on-constraint clause or a:where clause.

:on-constraint accepts a single SQL entity that identifies a constraint name.

Since :do-nothing is a SQL clause but has no associated data, it still has to have an arbitrary value because clauses are hash maps and that value will be ignored so :do-nothing true is a reasonable choices.

:do-update-set accepts either a single SQL entity (a keyword or symbol), or hash map of columns and values, like :set (above), or a hash map of fields (a sequence of SQL entities) and a where clause. For convenience of building clauses with helpers, it also accepts a sequence of one or more column names followed by an optional hash map: this is treated as an alternative form of the hash map with fields and a where clause. The single SQL entity and the list of fields produce SET clauses using EXCLUDED:

user=> (sql/format {:insert-into :companies
                    :values [{:name "Microsoft"}]
                    :on-conflict :name
                    :do-update-set :name})
["INSERT INTO companies (name) VALUES (?) ON CONFLICT (name) DO UPDATE SET name = EXCLUDED.name" "Microsoft"]
user=> (sql/format {:insert-into :companies
                    :values [{:name "Microsoft"}]
                    :on-conflict :name
                    :do-update-set {:name [:|| "was: " :EXCLUDED.name]}})
["INSERT INTO companies (name) VALUES (?) ON CONFLICT (name) DO UPDATE SET name = ? || EXCLUDED.name" "Microsoft" "was: "]
user=> (sql/format {:insert-into :companies
                    :values [{:name "Microsoft"}]
                    :on-conflict :name
                    :do-update-set {:fields [:name]
                                    :where [:<> :name nil]}})
["INSERT INTO companies (name) VALUES (?) ON CONFLICT (name) DO UPDATE SET name = EXCLUDED.name WHERE name IS NOT NULL" "Microsoft"]
user=> (sql/format {:insert-into :companies
                    :values [{:name "Microsoft"}]
                    :on-conflict {:on-constraint :name-idx}
                    :do-nothing true})
["INSERT INTO companies (name) VALUES (?) ON CONFLICT ON CONSTRAINT name_idx DO NOTHING" "Microsoft"]

returning

:returning 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.

Note: the actual formatting of a :returning clause is currently identical to the formatting of a :select clause.