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 (except for some natural grouping of related clauses).
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.
DDL clauses are listed first, followed by SQL clauses.
The examples herein assume:
(refer-clojure :exclude '[partition-by])
(require '[honey.sql :as sql]
'[honey.sql.helpers :as h :refer [select from join-by left-join join
where order-by over partition-by window]])
DDL Clauses
HoneySQL supports the following DDL clauses as a data DSL.
Several of these include column specifications and HoneySQL provides some special syntax (functions) to support that. See Column Descriptors in Special Syntax for more details.
Google BigQuery support:
[:bigquery/array :string]as a column type producesARRAY<STRING>and[:bigquery/struct col1-spec col2-spec]as a column type producesSTRUCT<col1, col2>(wherecolN-specis a vector specifying a named column).
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
:add-column [:id :int [:not nil] :if-not-exists]})
["ALTER TABLE fruit ADD COLUMN IF NOT EXISTS 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
:drop-column [:if-exists :ident]})
["ALTER TABLE fruit DROP COLUMN IF EXISTS 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"]
user=> (sql/format {:alter-table [:fruit
{:add-column [:id :int [:not nil]]}
{:add-column [:name [:varchar 32]]}
{:drop-column :ident}
{:modify-column [:appearance :text]}]})
["ALTER TABLE fruit ADD COLUMN id INT NOT NULL, ADD COLUMN name VARCHAR(32), DROP COLUMN ident, MODIFY COLUMN appearance TEXT"]
user=> (sql/format {:alter-table [:fruit
{:add-column [:id :int [:not nil] :if-not-exists]}
{:drop-column [:if-exists :ident]}]})
["ALTER TABLE fruit ADD COLUMN IF NOT EXISTS id INT NOT NULL, DROP COLUMN IF EXISTS 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"]
You can use :add-index to add a primary key to an existing table, as follows:
user=> (-> (h/alter-table :fruit)
(h/add-index :primary-key :id)
(sql/format))
["ALTER TABLE fruit ADD PRIMARY KEY(id)"]
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-tosince there is aRENAME TABLE old_name TO new_nameSQL 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]]})
["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, that allow things like CHECK for a
constraint, FOREIGN KEY (with a column name), REFERENCES
(with a pair of column names). See Column Descriptors in Special Syntax for more details.
create-table-as
:create-table-as can accept a single table name or a sequence
that starts with a table name, optionally followed by
a flag indicating the creation should be conditional
(:if-not-exists or the symbol if-not-exists),
optionally followed by a {:columns ..} clause to specify
the columns to use in the created table, optionally followed
by special syntax to specify TABLESPACE etc.
For example:
user=> (sql/format {:create-table-as [:metro :if-not-exists
{:columns [:foo :bar :baz]}
[:tablespace [:entity :quux]]],
:select [:*],
:from [:cities],
:where [:= :metroflag "y"],
:with-data false}
{:pretty true})
["
CREATE TABLE IF NOT EXISTS metro (foo, bar, baz) TABLESPACE quux AS
SELECT *
FROM cities
WHERE metroflag = ?
WITH NO DATA
" "y"]
Without the {:columns ..} clause, the table will be created
based on the columns in the query that follows.
A more concise version of the above can use the TABLE clause:
user=> (sql/format {:create-table-as [:metro :if-not-exists
{:columns [:foo :bar :baz]}
[:tablespace [:entity :quux]]],
:table :cities,
:where [:= :metroflag "y"],
:with-data false}
{:pretty true})
["
CREATE TABLE IF NOT EXISTS metro (foo, bar, baz) TABLESPACE quux AS
TABLE cities
WHERE metroflag = ?
WITH NO DATA
" "y"]
create-extension
:create-extension can accept a single extension name or a pair
of the extension name, followed by
a flag indicating the creation should be conditional
(:if-not-exists or the symbol if-not-exists).
See the PostgreSQL section for examples.
create-view, create-materialized-view, refresh-materialized-view
:create-view, :create-materialized-view, and
:refresh-materialized-view all accept a single view name
or a sequence of optional modifiers, followed by the view name,
followed by a flag indicating the creation should be conditional
(:if-not-exists or the symbol if-not-exists):
user=> (sql/format {:create-view :products
:select [:*]
:from [:items]
:where [:= :category "product"]})
["CREATE VIEW products AS SELECT * FROM items WHERE category = ?" "product"]
user=> (sql/format {:create-view [:products :if-not-exists]
:select [:*]
:from [:items]
:where [:= :category "product"]})
["CREATE VIEW IF NOT EXISTS products AS SELECT * FROM items WHERE category = ?" "product"]
user=> (sql/format {:refresh-materialized-view [:concurrently :products]
:with-data false})
["REFRESH MATERIALIZED VIEW CONCURRENTLY products WITH NO DATA"]
drop-table, drop-extension, drop-view, drop-materialized-view
:drop-table et al can accept a single table (extension, view) name or a sequence of
table (extension, view) 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 (extension, view) 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"]
SQL Pseudo-Syntax Clauses
The following data DSL clauses are supported to let you modify how SQL clauses are generated, if the default generation is incorrect or unsupported.
See also the Extending HoneySQL section.
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.
raw
This is pseudo-syntax that lets you insert a complete
SQL clause as a string, if HoneySQL doesn't support
some exotic SQL construct. It should rarely be
needed and it is mostly present to provide the same
functionality for clauses that [:raw ..] provides
for expressions (which usage is likely to be more common).
SQL Clauses
HoneySQL supports the following SQL clauses as a data DSL. These are listed in precedence order (i.e., matching the order they would appear in a valid SQL statement).
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, table
: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]
Here, :select has a three expressions as its argument. The first is
a simple column name. The second is an expression with no alias, which
is why it is still double-nested. The third is a simple column name and its alias.
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]
Here, :select has a three expressions as its argument. The first is
a simple column name. The second is an expression and its alias. The
third is a simple column name and its alias.
:select-distinct works the same way but produces SELECT DISTINCT.
Google BigQuery support: to provide
SELECT * EXCEPT ..andSELECT * REPLACE ..syntax, HoneySQL supports a vector starting with:*or the symbol*followed by except columns and/or replace expressions as columns:
user=> (sql/format {:select [[:* :except [:a :b :c]]] :from [:table]})
["SELECT * EXCEPT (a, b, c) FROM table"]
user=> (sql/format {:select [[:* :replace [[[:* :a [:inline 100]] :b] [[:inline 2] :c]]]] :from [:table]})
["SELECT * REPLACE (a * 100 AS b, 2 AS c) FROM table"]
user=> (sql/format {:select [[:* :except [:a :b] :replace [[[:inline 2] :c]]]] :from [:table]})
["SELECT * EXCEPT (a, b) REPLACE (2 AS c) FROM table"]
The :table clause is equivalent to :select :* :from and accepts just
a simple table name -- :create-table-as above for an example.
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"]
select-top, select-distinct-top
:select-top and :select-distinct-top are variants of :select
and :select-distinct, respectively, that provide support for
MS SQL Server's TOP modifier on a SELECT statement.
They accept a sequence that starts with an expression to be
used as the TOP limit value, followed by SQL entities as
supported by :select above.
The TOP expression can either be a general SQL expression
or a sequence whose first element is a general SQL expression,
followed by qualifiers for :percent and/or :with-ties (or
the symbols percent and/or with-ties).
user=> (sql/format {:select-top [[10 :percent :with-ties] :foo :baz] :from :bar :order-by [:quux]})
["SELECT TOP(?) PERCENT WITH TIES foo, baz FROM bar ORDER BY quux ASC" 10]
into
Used for selecting rows into a new table, optional in another database:
user=> (sql/format '{select * into newtable from mytable})
["SELECT * INTO newtable FROM mytable"]
user=> (sql/format '{select * into [newtable otherdb] from mytable})
["SELECT * INTO newtable IN otherdb FROM mytable"]
bulk-collect-into
Used for selecting rows into an array variable, with an optional limit:
user=> (sql/format '{select * bulk-collect-into arrv from mytable})
["SELECT * BULK COLLECT INTO arrv FROM mytable"]
user=> (sql/format '{select * bulk-collect-into [arrv 100] from mytable})
["SELECT * BULK COLLECT INTO arrv LIMIT ? FROM mytable" 100]
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 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"]
Note: if you specify
:columnsfor an:insert-intothat also includes column names, you will get invalid SQL. Similarly, if you specify:columnswhen:valuesis based on hash maps, you will get invalid SQL. Since clauses are generated independently, there is no cross-checking performed if you provide an illegal combination of clauses.
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.x 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
:fromclause is currently identical to the formatting of a:selectclause.
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
:usingclause is currently identical to the formatting of a:selectclause.
join-by
This is a convenience that allows for an arbitrary sequence of JOIN
operations to be performed in a specific order. It accepts either a sequence
of alternating join operation name (keyword or symbol) and the clause that join
would take, or a sequence of JOIN clauses as hash maps:
user=> (sql/format {:select [:t.ref :pp.code]
:from [[:transaction :t]]
:join-by [:left [[:paypal-tx :pp]
[:using :id]]
:join [[:logtransaction :log]
[:= :t.id :log.id]]]
:where [:= "settled" :pp.status]}
{:pretty true})
["
SELECT t.ref, pp.code
FROM transaction AS t
LEFT JOIN paypal_tx AS pp USING (id) INNER JOIN logtransaction AS log ON t.id = log.id
WHERE ? = pp.status
" "settled"]
;; or the equivalent using helpers:
user=> (sql/format (-> (select :t.ref :pp.code)
(from [:transaction :t])
(join-by (left-join [:paypal-tx :pp]
[:using :id])
(join [:logtransaction :log]
[:= :t.id :log.id]))
(where := "settled" :pp.status))
{:pretty true})
["
SELECT t.ref, pp.code
FROM transaction AS t
LEFT JOIN paypal_tx AS pp USING (id) INNER JOIN logtransaction AS log ON t.id = log.id
WHERE ? = pp.status
" "settled"]
Without :join-by, a :join would normally be generated before a :left-join.
To avoid repetition, :join-by allows shorthand versions of the join clauses
using a keyword (or symbol) without the -join suffix, as shown in this example.
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]
:join is shorthand for :inner-join.
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 expressions. Each expression can either be a
simple table name (keyword or symbol) or a pair of a
table expression and an alias.
user=> (sql/format {:select [:foo.id [:x.id :x_id] :x.value]
:cross-join [[[:lateral
[:jsonb_to_recordset :foo.json_value]]
[[:raw "x(id text, value jsonb)"]]]]
:from [:foo]})
["SELECT foo.id, x.id AS x_id, x.value FROM foo CROSS JOIN LATERAL JSONB_TO_RECORDSET(foo.json_value) x(id text, value jsonb)"]
Here, :cross-join has a one expression as its argument, which is a
table expression and an alias. The table expression is [:lateral ..]
and the alias expression is double-nested so that it is read as a
function call: an invocation of :raw.
Note: the actual formatting of a
:cross-joinclause is currently identical to the formatting of a:selectclause.
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.
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
convert a hash map of values into a condition that you can use
in a WHERE clause to match against those columns and values:
user=> (sql/format {:select :* :from :transaction :where (sql/map= {:type "sale" :productid 123})})
["SELECT * FROM transaction WHERE (type = ?) AND (productid = ?)" "sale" 123]
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]}]}
{:pretty true})
["
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)))
{:pretty true})
["
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, :desc, :nulls-first, :desc-null-last,
etc -- 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, fetch
Some databases, including MySQL, support :limit and :offset
for paginated queries, other databases support :offset and
:fetch for that (which is ANSI-compliant and should be
preferred if your database supports it). All three expect a
single SQL expression:
user=> (sql/format {:select [:id :name]
:from [:table]
:limit 10 :offset 20})
["SELECT id, name FROM table LIMIT ? OFFSET ?" 10 20]
user=> (sql/format {:select [:id :name]
:from [:table]
:offset 20 :fetch 10})
["SELECT id, name FROM table OFFSET ? ROWS FETCH NEXT ? ROWS ONLY" 20 10]
All three are available in all dialects for HoneySQL so it is up to you to choose the correct pair for your database.
If you use :offset and :limit together, OFFSET will just have
the number of rows. If you use :offset and :fetch together,
OFFSET will have the number of rows and the ROWS keyword. If
you use :offset on its own, it will have just the number
of rows, unless you have the :sqlserver dialect selected,
it which case it will have the ROWS keywords as well.
This seemed to be the least risky change in 2.0.0 RC 5 to avoid introducing a breaking change.
If the number of rows is one, ROW will be used instead of ROWS.
If :fetch is specified without :offset, FIRST will be used instead of NEXT.
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.
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
either NULL or DEFAULT values for any missing keys (columns).
By default, NULL is used but you can specify a set of columns
to get DEFAULT values, via the :values-default-columns option.
In the latter case -- a sequence of sequences --
all of the rows are padded to the same length by adding nil
values if needed (since :values does not know how or if column
names are being used in this case).
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"]
user=> (sql/format '{insert-into table
values ({id 1 name "Sean"}
{id 2}
{name "Extra"})}
{:values-default-columns #{'id}})
["INSERT INTO table (id, name) VALUES (?, ?), (?, NULL), (DEFAULT, ?)" 1 "Sean" 2 "Extra"]
Note: the
:values-default-columnsoption must match how the columns are specified, i.e., as symbols or keywords.
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 a sequence of zero or more
SQL entities (keywords or symbols), optionally
followed by a single SQL clause (hash map). It can also
accept either a single SQL entity or a single SQL clause.
The SQL entities are column names and the SQL clause can be an
:on-constraint clause or a:where clause.
[For convenience of use with the on-conflict helper, this clause can also accept any of those arguments, wrapped in a sequence; it can also accept an empty sequence, and just produce ON CONFLICT, so that it can be combined with other clauses directly]
: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"]
;; empty :on-conflict combined with :on-constraint clause:
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"]
on-duplicate-key-update
This is the MySQL equivalent of on-update-set described above.
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
:returningclause is currently identical to the formatting of a:selectclause.
with-data
:with-data accepts a single boolean argument and produces
either WITH DATA, for a true argument, or WITH NO DATA,
for a false argument.
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