Added validation ns.

project.clj

@@ -17,7 +17,7 @@
                  [mysql/mysql-connector-java "5.1.26"]
                  [slingshot "0.10.3"]
                  [sqlingvo "0.5.6"]]
-  :profiles {:dev {:dependencies [[validation-clj "0.5.5"]
+  :profiles {:dev {:dependencies [[validation-clj "0.5.6"]
                                   [org.slf4j/slf4j-log4j12 "1.7.5"]
                                   [c3p0/c3p0 "0.9.1.2"]
                                   [com.jolbox/bonecp "0.7.1.RELEASE"]]

src/datumbazo/validation.clj

@@ -0,0 +1,28 @@
+(ns datumbazo.validation
+  (:refer-clojure :exclude [replace])
+  (:require [clojure.string :refer [blank?]]
+            [datumbazo.core :refer [select from limit run1 where]]))
+
+(defn new-record? [record]
+  (blank? (str (:id record))))
+
+(defn uniqueness-of
+  "Validates that the record's attributes are unique."
+  [db table columns & {:keys [error] :as opts}]
+  (fn [record]
+    (let [error (or error "has already been taken")
+          columns (if (sequential? columns) columns [columns])
+          vals (map record columns)
+          condition `(and ~@(map (fn [c v] `(= ~c ~v)) columns vals))]
+      (if (and (or (nil? (:if opts))
+                   ((:if opts) record))
+               (run1 db (select columns
+                          (from table)
+                          (where condition)
+                          (limit 1))))
+        (reduce
+         (fn [record column]
+           (with-meta record
+             (assoc-in (meta record) [:errors column] error)))
+         record columns)
+        record))))

test/datumbazo/core_test.clj

@@ -5,6 +5,7 @@
             [clojure.java.io :refer [file]]
             [environ.core :refer [env]]
             [validation.core :refer :all]
+            [datumbazo.validation :refer [new-record? uniqueness-of]]
             [slingshot.slingshot :refer [try+]])
   (:use clojure.test
         datumbazo.core

test/datumbazo/validation_test.clj

@@ -0,0 +1,15 @@
+(ns datumbazo.validation-test
+  (:require [clojure.test :refer :all]
+            [datumbazo.core :refer [run1]]
+            [datumbazo.validation :refer :all]
+            [slingshot.slingshot :refer [try+]]
+            [sqlingvo.core :refer [sql]]
+            [validation.core :refer :all]))
+
+(deftest test-uniqueness-of
+  (with-redefs [run1 (fn [db stmt]
+                       (is (= ["SELECT \"nick\" FROM \"users\" WHERE (\"nick\" = ?) LIMIT 1" "Bob"]
+                              (sql stmt)))
+                       [])]
+    (let [errors (:errors (meta ((uniqueness-of nil :users :nick) {:nick "Bob"})))]
+      (is (= "has already been taken" (:nick errors))))))