toucan2.core — io.github.camsaul/toucan2 0.9.1

Convenience namespace exposing the most common parts of the library's public API for day-to-day usage (i.e., not implementing anything advanced)

batched-hydrate clj

(batched-hydrate model k rows)

changes clj

(changes instance)

Get a map with any changes made to instance since it came out of the DB. Only includes keys that have been added or given different values; keys that were removed are not counted. Returns nil if there are no changes.

compile clj macro

(compile & body)

Return the compiled query that would be executed by a form, rather than executing that form itself.

(delete/delete :table :id 1) => ["DELETE FROM table WHERE ID = ?" 1]

count clj

(count modelable & kv-args? query?)

current clj

(current instance)

Return the underlying map representing the current state of an instance.

default-connectable clj

(default-connectable model)

The default connectable that should be used when executing queries for model if no toucan2.connection/*current-connectable* is currently bound. By default, this just returns the global default connectable, :default, but you can tell Toucan to use a different default connectable for a model by implementing this method.

define-after-insert clj macro

(define-after-insert model [instance-binding] & body)

define-after-select clj macro

(define-after-select model [instance-binding] & body)

define-after-update clj macro

(define-after-update model [instance-binding] & body)

define-before-delete clj macro

(define-before-delete model [instance-binding] & body)

define-before-insert clj macro

(define-before-insert model [instance-binding] & body)

define-before-select clj macro

(define-before-select model [args-binding] & body)

(define-before-select [model query-class] [args-binding] & body)

define-before-update clj macro

(define-before-update model [row-binding] & body)

define-default-fields clj macro

(define-default-fields model & body)

deftransforms clj macro

(deftransforms model transforms)

Define type transforms to use for a specific model. transforms should be a map of

{:column-name {:in <fn>, :out <fn>}}

:in transforms are applied to values going over the wire to the database; these generally only applied to values passed at or near the top level to various functions; don't expect Toucan 2 to parse your SQL to find out which parameter corresponds to what in order to apply transforms or to apply transforms inside JOINS in hand-written HoneySQL. That said, unless you're doing something weird your transforms should generally get applied.

:out transforms are applied to values coming out of the database; since nothing weird really happens there this is done consistently.

Transform functions for either case are skipped for nil values.

Example:

(deftransforms :models/user {:type {:in name, :out keyword}})

You can also define transforms independently, and derive a model from them:

(deftransforms ::type-keyword {:type {:in name, :out keyword}})

(derive :models/user ::type-keyword) (derive :models/user ::some-other-transform)

Don't derive a model from multiple deftransforms for the same key in the same direction.

When multiple transforms match a given model they are combined into a single map of transforms with merge-with merge. If multiple transforms match a given column in a given direction, only one of them will be used; you should assume which one is used is indeterminate. (This may be made an error, or at least a warning, in the future.)

Until upstream issue https://github.com/camsaul/methodical/issues/97 is resolved, you will have to specify which method should be applied first in cases of ambiguity using [[methodical.core/prefer-method!]]:

(m/prefer-method! transformed/transforms ::user-with-location ::user-with-password)

If you want to override transforms completely for a model, and ignore transforms from ancestors of a model, you can create an :around method:

(defmethod toucan2.tools.transformed/transforms :around ::my-model [_model] {:field {:in name, :out keyword}})

delete! clj

(delete! modelable & conditions? query?)

Returns number of rows deleted.

do-with-connection clj

(do-with-connection connectable f)

exists? clj

(exists? modelable & kv-args? query?)

global-honeysql-options clj

hydrate clj

(hydrate results k & ks)

Hydrate a single object or sequence of objects.

Automagic Batched Hydration (via [[toucan2.hydrate/model-for-automagic-hydration]])

[[toucan2.hydrate/hydrate]] attempts to do a batched hydration where possible. If the key being hydrated is defined as one of some table's [[toucan2.hydrate/model-for-automagic-hydration]], hydrate will do a batched toucan2.select/select if a corresponding key (by default, the same key suffixed by -id) is found in the objects being batch hydrated. The corresponding key can be customized by implementing [[toucan2.hydrate/fk-keys-for-automagic-hydration]].

(hydrate [{:user_id 100}, {:user_id 101}] :user)

Since :user is a hydration key for :models/User, a single toucan2.select/select will used to fetch Users:

(db/select :models/User :id [:in #{100 101}])

The corresponding Users are then added under the key :user.

Function-Based Batched Hydration (via [[toucan2.hydrate/batched-hydrate]] methods)

If the key can't be hydrated auto-magically with the appropriate [[toucan2.hydrate/model-for-automagic-hydration]], [[toucan2.hydrate/hydrate]] will attempt to do batched hydration if it can find a matching method for [[toucan2.hydrate/batched-hydrate]]. If a matching function is found, it is called with a collection of objects, e.g.

(m/defmethod hydrate/batched-hydrate [:default :fields] [_model _k rows] (let [id->fields (get-some-fields rows)] (for [row rows] (assoc row :fields (get id->fields (:id row))))))

Simple Hydration (via [[toucan2.hydrate/simple-hydrate]] methods)

If the key is not eligible for batched hydration, [[toucan2.hydrate/hydrate]] will look for a matching [[toucan2.hydrate/simple-hydrate]] method. simple-hydrate is called with a single row.

(m/defmethod simple-hydrate [:default :dashboard] [_model _k {:keys [dashboard-id], :as row}] (assoc row :dashboard (select/select-one :models/Dashboard :toucan/pk dashboard-id)))

Hydrating Multiple Keys

You can hydrate several keys at one time:

(hydrate {...} :a :b) -> {:a 1, :b 2}

Nested Hydration

You can do recursive hydration by listing keys inside a vector:

(hydrate {...} [:a :b]) -> {:a {:b 1}}

The first key in a vector will be hydrated normally, and any subsequent keys will be hydrated inside the corresponding values for that key.

(hydrate {...} [:a [:b :c] :e]) -> {:a {:b {:c 1} :e 2}}

insert! clj

(insert! modelable row-or-rows)

(insert! modelable columns row-vectors)

(insert! modelable k v & more)

Returns number of rows inserted.

insert-returning-instances! clj

(insert-returning-instances! modelable row-or-rows)

(insert-returning-instances! [modelable & columns-to-return] row-or-rows)

(insert-returning-instances! modelable columns row-vectors)

(insert-returning-instances! [modelable & columns-to-return]
                             columns
                             row-vectors)

(insert-returning-instances! modelable k v & more)

(insert-returning-instances! [modelable & columns-to-return] k v & more)

Like insert!, but returns a vector of the primary keys of the newly inserted rows rather than the number of rows inserted. The primary keys are determined by model/primary-keys. For models with a single primary key, this returns a vector of single values, e.g. [1 2] if the primary key is :id and you've inserted rows 1 and 2; for composite primary keys this returns a vector of tuples where each tuple has the value of corresponding primary key as returned by model/primary-keys, e.g. for composite PK [:id :name] you might get [[1 "Cam"] [2 "Sam"]].

insert-returning-pks! clj

(insert-returning-pks! modelable row-or-rows)

(insert-returning-pks! modelable columns row-vectors)

(insert-returning-pks! modelable k v & more)

Like insert!, but returns a vector of the primary keys of the newly inserted rows rather than the number of rows inserted. The primary keys are determined by model/primary-keys. For models with a single primary key, this returns a vector of single values, e.g. [1 2] if the primary key is :id and you've inserted rows 1 and 2; for composite primary keys this returns a vector of tuples where each tuple has the value of corresponding primary key as returned by model/primary-keys, e.g. for composite PK [:id :name] you might get [[1 "Cam"] [2 "Sam"]].

instance clj

(instance model)

(instance model m)

(instance model k v & more)

instance-of? clj

(instance-of? model x)

True if x is a Toucan2 instance, and its [[protocols/model]] isa? model.

(instance-of? ::bird (instance ::toucan {})) ; -> true (instance-of? ::toucan (instance ::bird {})) ; -> false

instance? clj

(instance? x)

True if x is a Toucan2 instance, i.e. a toucan2.instance.Instance or some other class that satisfies the correct interfaces.

Toucan instances need to implement [[IModel]], [[IWithModel]], and [[IRecordChanges]].

model clj

(model this)

Get the Toucan model associated with this.

model-for-automagic-hydration clj

(model-for-automagic-hydration original-model k)

The model that should be used to automagically hydrate the key k in instances of original-model.

(model-for-automagic-hydration :some-table :user) :-> :myapp.models/user

original clj

(original instance)

Get the original version of instance as it appeared when it first came out of the DB.

primary-key-values clj

(primary-key-values instance)

(primary-key-values model m)

Return a map of primary key values for a Toucan 2 instance.

primary-keys clj

(primary-keys model)

Return a sequence of the primary key columns names, as keywords, for a model.

primary-keys-vec clj

(primary-keys-vec model)

Get the primary keys for a model as a vector.

query clj

(query queryable)

(query connectable queryable)

(query connectable modelable queryable)

query-one clj

(query-one queryable)

(query-one connectable queryable)

(query-one connectable modelable queryable)

reducible-insert clj

(reducible-insert modelable row-or-rows)

(reducible-insert modelable columns row-vectors)

(reducible-insert modelable k v & more)

reducible-insert-returning-instances clj

(reducible-insert-returning-instances modelable row-or-rows)

(reducible-insert-returning-instances [modelable & columns-to-return]
                                      row-or-rows)

(reducible-insert-returning-instances modelable columns row-vectors)

(reducible-insert-returning-instances [modelable & columns-to-return]
                                      columns
                                      row-vectors)

(reducible-insert-returning-instances modelable k v & more)

(reducible-insert-returning-instances [modelable & columns-to-return]
                                      k
                                      v
                                      &
                                      more)

reducible-insert-returning-pks clj

(reducible-insert-returning-pks modelable row-or-rows)

(reducible-insert-returning-pks modelable columns row-vectors)

(reducible-insert-returning-pks modelable k v & more)

reducible-query clj

(reducible-query queryable)

(reducible-query connectable queryable)

(reducible-query connectable modelable queryable)

reducible-select clj

(reducible-select modelable & kv-args? query?)

(reducible-select [modelable & columns] & kv-args? query?)

reducible-update clj

(reducible-update modelable
                  pk?
                  conditions-map-or-query?
                  &
                  conditions-kv-args
                  changes-map)

reducible-update-returning-pks clj

(reducible-update-returning-pks modelable
                                pk?
                                conditions-map-or-query?
                                &
                                conditions-kv-args
                                changes-map)

save! clj

(save! object)

select clj

(select modelable & kv-args? query?)

(select [modelable & columns] & kv-args? query?)

select-fn->fn clj

(select-fn->fn f1 f2 modelable & kv-args? query?)

select-fn->pk clj

(select-fn->pk f modelable & kv-args? query?)

select-fn-reducible clj

(select-fn-reducible f modelable & kv-args? query?)

select-fn-set clj

(select-fn-set f modelable & kv-args? query?)

Like select, but returns a set of values of (f instance) for the results. Returns nil if the set is empty.

select-fn-vec clj

(select-fn-vec f modelable & kv-args? query?)

Like select, but returns a vector of values of (f instance) for the results. Returns nil if the vector is empty.

select-one clj

(select-one modelable & kv-args? query?)

(select-one [modelable & columns] & kv-args? query?)

select-one-fn clj

(select-one-fn f modelable & kv-args? query?)

select-one-pk clj

(select-one-pk modelable & kv-args? query?)

select-pk->fn clj

(select-pk->fn f modelable & kv-args? query?)

select-pks-fn clj

(select-pks-fn modelable)

Return a function to get the value(s) of the primary key(s) from a row. Used by toucan2.select/select-pks-reducible and thus by toucan2.select/select-pks-set, toucan2.select/select-pks-vec, etc.

The primary keys are determined by toucan2.model/primary-keys. By default this is simply the keyword :id.

select-pks-set clj

(select-pks-set modelable & kv-args? query?)

select-pks-vec clj

(select-pks-vec modelable & kv-args? query?)

simple-hydrate clj

(simple-hydrate model k row)

Implementations should return a version of map row with the key k added.

table-name clj

(table-name model)

transforms clj

(transforms model)

Return a map of

{column-name {:in <fn>, :out <fn>}}

For a given model, all matching transforms are combined with merge-with merge in an indeterminate order, so don't try to specify multiple transforms for the same column in the same direction for a given model -- compose your transform functions instead if you want to do that. See toucan2.tools.helpers/deftransforms for more info.

update! clj

(update! modelable
         pk?
         conditions-map-or-query?
         &
         conditions-kv-args
         changes-map)

update-returning-pks! clj

(update-returning-pks! modelable
                       pk?
                       conditions-map-or-query?
                       &
                       conditions-kv-args
                       changes-map)

with-call-count clj macro

(with-call-count [call-count-fn-binding] & body)

Execute body, trackingthe number of database queries and statements executed. This number can be fetched at any time withing body by calling function bound to call-count-fn-binding:

(with-call-count [call-count] (select ...) (println "CALLS:" (call-count)) (insert! ...) (println "CALLS:" (call-count))) ;; -> CALLS: 1 ;; -> CALLS: 2

with-compiled-query clj macro

(with-compiled-query [query-binding [model query]] & body)

with-connection clj macro

(with-connection [connection-binding connectable] & body)

(with-connection [connection-binding connectable] & body)

with-model clj macro

(with-model [model-binding modelable] & body)

with-transaction clj macro

(with-transaction [conn-binding connectable] & body)