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RowBuilder (clj)
(source)protocol
Protocol for building rows in various representations.
The default implementation for building hash maps: `MapResultSetBuilder`
Examples
next-jdbc
What's left to be tested:
* ReadableColumn protocol extension point"
(:require [clojure.core.protocols :as core-p]
[clojure.datafy :as d]
[clojure.string :as str]
[clojure.test :refer [deftest is testing use-fixtures]]
[next.jdbc.protocols :as p]
[next.jdbc.result-set :as rs]
[next.jdbc.specs :as specs]
[next.jdbc.test-fixtures :refer [with-test-db ds column
default-options
derby? mssql? mysql? postgres?]])
(:import (java.sql ResultSet ResultSetMetaData)))
(deftest test-mapify
(testing "no row builder is used"
(is (= [true]
(into [] (map map?) ; it looks like a real map now
(p/-execute (ds) ["select * from fruit where id = ?" 1]
{:builder-fn (constantly nil)}))))
(is (= ["Apple"]
(into [] (map :name) ; keyword selection works
(p/-execute (ds) ["select * from fruit where id = ?" 1]
{:builder-fn (constantly nil)}))))
(is (= [[2 [:name "Banana"]]]
(into [] (map (juxt #(get % "id") ; get by string key works
#(find % :name))) ; get MapEntry works
(p/-execute (ds) ["select * from fruit where id = ?" 2]
{:builder-fn (constantly nil)}))))
(is (= [{:id 3 :name "Peach"}]
(into [] (map #(select-keys % [:id :name])) ; select-keys works
(p/-execute (ds) ["select * from fruit where id = ?" 3]
{:builder-fn (constantly nil)}))))
(is (= [[:orange 4]]
(into [] (map #(vector (if (contains? % :name) ; contains works
(keyword (str/lower-case (:name %)))
:unnamed)
(get % :id 0))) ; get with not-found works
(p/-execute (ds) ["select * from fruit where id = ?" 4]
{:builder-fn (constantly nil)}))))
(is (= [{}]
(into [] (map empty) ; return empty map without building
(p/-execute (ds) ["select * from fruit where id = ?" 1]
{:builder-fn (constantly nil)})))))
(testing "count does not build a map"
(let [count-builder (fn [_1 _2]
(reify rs/RowBuilder
(column-count [_] 13)))]
(is (= [13]
(into [] (map count) ; count relies on columns, not row fields
(p/-execute (ds) ["select * from fruit where id = ?" 1]
{:builder-fn count-builder}))))))
(testing "assoc, dissoc, cons, seq, and = build maps"
(is (map? (reduce (fn [_ row] (reduced (assoc row :x 1)))
nil
(p/-execute (ds) ["select * from fruit"] {}))))
(is (= 6 (count (reduce (fn [_ row] (reduced (assoc row :x 1)))
nil
(p/-execute (ds) ["select * from fruit"] {})))))
(is (map? (reduce (fn [_ row] (reduced
(dissoc row (column :FRUIT/NAME))))
nil
(p/-execute (ds) ["select * from fruit"]
(default-options)))))
(is (= 4 (count (reduce (fn [_ row] (reduced
(dissoc row (column :FRUIT/NAME))))
nil
(p/-execute (ds) ["select * from fruit"]
(default-options))))))
(is (seq? (reduce (fn [_ row] (reduced (seq row)))
nil
(p/-execute (ds) ["select * from fruit"] {}))))
(is (seq? (reduce (fn [_ row] (reduced (cons :seq row)))
nil
(p/-execute (ds) ["select * from fruit"] {}))))
(is (= :seq (first (reduce (fn [_ row] (reduced (cons :seq row)))
nil
(p/-execute (ds) ["select * from fruit"] {})))))
(is (false? (reduce (fn [_ row] (reduced (= row {})))
nil
(p/-execute (ds) ["select * from fruit"] {}))))
(is (map-entry? (second (reduce (fn [_ row] (reduced (cons :seq row)))
nil
(p/-execute (ds) ["select * from fruit"] {})))))
(is (every? map-entry? (reduce (fn [_ row] (reduced (seq row)))
nil
(p/-execute (ds) ["select * from fruit"] {}))))
(is (map? (reduce (fn [_ row] (reduced (conj row {:a 1})))
nil
(p/-execute (ds) ["select * from fruit"] {}))))
(is (map? (reduce (fn [_ row] (reduced (conj row [:a 1])))
nil
(p/-execute (ds) ["select * from fruit"] {}))))
(is (map? (reduce (fn [_ row] (reduced (conj row {:a 1 :b 2})))
nil
(p/-execute (ds) ["select * from fruit"] {}))))
(is (= 1 (:a (reduce (fn [_ row] (reduced (conj row {:a 1})))
nil
(p/-execute (ds) ["select * from fruit"] {})))))
(is (= 1 (:a (reduce (fn [_ row] (reduced (conj row [:a 1])))
nil
(p/-execute (ds) ["select * from fruit"] {})))))
(is (= 1 (:a (reduce (fn [_ row] (reduced (conj row {:a 1 :b 2})))
nil
(p/-execute (ds) ["select * from fruit"] {})))))
(is (= 2 (:b (reduce (fn [_ row] (reduced (conj row {:a 1 :b 2})))
nil
(p/-execute (ds) ["select * from fruit"] {})))))
(is (vector? (reduce (fn [_ row] (reduced (conj row :a)))
nil
(p/-execute (ds) ["select * from fruit"]
{:builder-fn rs/as-arrays}))))
(is (= :a (peek (reduce (fn [_ row] (reduced (conj row :a)))
nil
(p/-execute (ds) ["select * from fruit"]
{:builder-fn rs/as-arrays})))))
(is (= :b (peek (reduce (fn [_ row] (reduced (conj row :a :b)))
nil
(p/-execute (ds) ["select * from fruit"]
{:builder-fn rs/as-arrays}))))))
(testing "datafiable-row builds map; with metadata"
(is (map? (reduce (fn [_ row] (reduced (rs/datafiable-row row (ds) {})))
nil
(p/-execute (ds) ["select * from fruit"] {}))))
(is (contains? (meta (reduce (fn [_ row] (reduced (rs/datafiable-row row (ds) {})))
nil
(p/-execute (ds) ["select * from fruit"] {})))
`core-p/datafy))))
(defn fruit-builder [^ResultSet rs ^ResultSetMetaData rsmeta]
(reify
rs/RowBuilder
(->row [_] (->Fruit (.getObject rs "id")
(.getObject rs "name")
(.getObject rs "appearance")
(.getObject rs "cost")
(.getObject rs "grade")))
(column-count [_] 0) ; no need to iterate over columns
(with-column [_ row i] row)
(with-column-value [_ row col v] row)
(row! [_ row] row)
rs/ResultSetBuilder
(->rs [_] (transient []))
(with-row [_ rs row] (conj! rs row))
(rs! [_ rs] (persistent! rs))
clojure.lang.ILookup ; only supports :cols and :rsmeta
(valAt [this k] (get this k nil))
(valAt [this k not-found]
(case k
:cols [:id :name :appearance :cost :grade]
:rsmeta rsmeta
not-found))))