[Issue #50] Removes keys with undefined values.

.gitignore

@@ -10,7 +10,7 @@ lib-cov
 *.out
 *.pid
 *.gz
-
+.lvimrc
 pids
 logs
 results

lib/postgresql.js

@@ -256,6 +256,7 @@ PostgreSQL.prototype._categorizeProperties = function(model, data) {
  */
 PostgreSQL.prototype.create = function (model, data, callback) {
   var self = this;
+  data = self.filterUndefined(data);
   var props = self._categorizeProperties(model, data);
 
   var sql = [];
@@ -294,6 +295,7 @@ PostgreSQL.prototype.create = function (model, data, callback) {
 /*
 PostgreSQL.prototype.updateOrCreate = function (model, data, callback) {
   var self = this;
+  data = self.filterUndefined(data);
   var props = self._categorizeProperties(model, data);
   var idColumns = props.ids.map(function(key) {
     return self.columnEscaped(model, key); }
@@ -342,6 +344,7 @@ PostgreSQL.prototype.updateOrCreate = function (model, data, callback) {
  */
 PostgreSQL.prototype.save = function (model, data, callback) {
   var self = this;
+  data = self.filterUndefined(data);
   var props = self._categorizeProperties(model, data);
 
   var sql = [];
@@ -360,6 +363,7 @@ PostgreSQL.prototype.save = function (model, data, callback) {
 PostgreSQL.prototype.update =
   PostgreSQL.prototype.updateAll = function (model, where, data, callback) {
     var whereClause = this.buildWhere(model, where);
+    data = this.filterUndefined(data);
 
     var sql = ['UPDATE ', this.tableEscaped(model), ' SET ',
       this.toFields(model, data), ' ', whereClause].join('');
@@ -373,6 +377,24 @@ PostgreSQL.prototype.update =
     });
   };
 
+/*!
+ * Filters undefined values from model instance data
+ *
+ * @param {Object} The model instance data
+ */
+
+PostgreSQL.prototype.filterUndefined = function (data) {
+  // There is no undefined in PostgreSQL and sending NULL for every
+  // undefined field prevents the database from handling default values.
+  //
+  // If you actually want to send NULL values, use NULL values.
+  Object.keys(data).forEach(function (k) {
+    if (data[k] === undefined) delete data[k];
+  });
+
+  return data;
+}
+
 /*!
  * Build a list of column name/value pairs
  *
@@ -382,6 +404,7 @@ PostgreSQL.prototype.update =
  */
 PostgreSQL.prototype.toFields = function (model, data, forCreate) {
   var self = this;
+
   var props = self._categorizeProperties(model, data);
   var dataIdNames = props.idsInData;
   var nonIdsInData = props.nonIdsInData;