fix(belongsTo): now correctly creates foreign key constraints when targetyKey is…

… a unique key and table has a primary key, closes #4455

changelog.md

@@ -4,6 +4,7 @@
 - [FIXED] Reload doesn't synchronize a null include [#4353](https://github.com/sequelize/sequelize/issues/4353)
 - [FIXED] commit/rollback multiple times on same transaction [#4491](https://github.com/sequelize/sequelize/issues/4491)
 - [FIXED] memory leak / options mangle for scopes with include [#4470](https://github.com/sequelize/sequelize/issues/4470)
+- [FIXED] custom `targetKey` for belongsTo on a target with a primary key will now correctly create foreign key constraints [#4455](https://github.com/sequelize/sequelize/issues/4455)
 
 # 3.8.0
 - [ADDED] `version` on `Sequelize` returning the current npm/package.json version [#4459](https://github.com/sequelize/sequelize/pull/4459)

lib/associations/belongs-to.js

@@ -61,6 +61,8 @@ var BelongsTo = function(source, target, options) {
   }
 
   this.targetKey = this.options.targetKey || this.target.primaryKeyAttribute;
+  this.targetKeyField = this.target.rawAttributes[this.targetKey].field || this.targetKey;
+
   this.targetIdentifier = this.targetKey;
   this.associationAccessor = this.as;
   this.options.useHooks = options.useHooks;
@@ -115,7 +117,7 @@ BelongsTo.prototype.injectAttributes = function() {
     this.options.onUpdate = this.options.onUpdate || 'CASCADE';
   }
 
-  Helpers.addForeignKeyConstraints(newAttributes[this.foreignKey], this.target, this.source, this.options);
+  Helpers.addForeignKeyConstraints(newAttributes[this.foreignKey], this.target, this.source, this.options, this.targetKeyField);
   Utils.mergeDefaults(this.source.rawAttributes, newAttributes);
 
   this.identifierField = this.source.rawAttributes[this.foreignKey].field || this.foreignKey;

lib/associations/helpers.js

@@ -12,7 +12,7 @@ function checkNamingCollision (association) {
   }
 }
 
-function addForeignKeyConstraints (newAttribute, source, target, options) {
+function addForeignKeyConstraints (newAttribute, source, target, options, key) {
   // FK constraints are opt-in: users must either set `foreignKeyConstraints`
   // on the association, or request an `onDelete` or `onUpdate` behaviour
 
@@ -20,8 +20,8 @@ function addForeignKeyConstraints (newAttribute, source, target, options) {
 
     // Find primary keys: composite keys not supported with this approach
     var primaryKeys = Utils._.chain(source.rawAttributes).keys()
-      .filter(function(key) { return source.rawAttributes[key].primaryKey; })
-      .map(function(key) { return source.rawAttributes[key].field || key; }).value();
+      .filter(function($key) { return source.rawAttributes[$key].primaryKey; })
+      .map(function($key) { return source.rawAttributes[$key].field || $key; }).value();
 
     if (primaryKeys.length === 1) {
       if (!!source.options.schema) {
@@ -38,7 +38,7 @@ function addForeignKeyConstraints (newAttribute, source, target, options) {
         newAttribute.references = { model: source.tableName };
       }
 
-      newAttribute.references.key = primaryKeys[0];
+      newAttribute.references.key = key || primaryKeys[0];
       newAttribute.onDelete = options.onDelete;
       newAttribute.onUpdate = options.onUpdate;
     }

test/integration/associations/belongs-to.test.js

@@ -616,9 +616,10 @@ describe(Support.getTestDialectTeaser('BelongsTo'), function() {
       });
     });
 
-    it('should support a non-primary key as the association column', function() {
+    it('should support a non-primary key as the association column on a target without a primary key', function() {
       var User = this.sequelize.define('User', { username: DataTypes.STRING })
         , Task = this.sequelize.define('Task', { title: DataTypes.STRING });
+
       User.removeAttribute('id');
       Task.belongsTo(User, { foreignKey: 'user_name', targetKey: 'username'});
 
@@ -637,6 +638,35 @@ describe(Support.getTestDialectTeaser('BelongsTo'), function() {
       });
     });
 
+    it('should support a non-primary unique key as the association column', function() {
+      var User = this.sequelize.define('User', {
+            username: {
+              type: DataTypes.STRING,
+              field: 'user_name',
+              unique: true
+            }
+          })
+        , Task = this.sequelize.define('Task', {
+            title: DataTypes.STRING
+          });
+
+      Task.belongsTo(User, { foreignKey: 'user_name', targetKey: 'username'});
+
+      return this.sequelize.sync({ force: true }).then(function() {
+        return User.create({ username: 'bob' }).then(function(newUser) {
+          return Task.create({ title: 'some task' }).then(function(newTask) {
+            return newTask.setUser(newUser).then(function() {
+              return Task.findOne({title: 'some task'}).then(function (foundTask) {
+                return foundTask.getUser().then(function (foundUser) {
+                  expect(foundUser.username).to.equal('bob');
+                });
+              });
+            });
+          });
+        });
+      });
+    });
+
     it('should support a non-primary key as the association column with a field option', function() {
       var User = this.sequelize.define('User', {
           username: {