fix #139, allow embedded queries in FROM

lib/db/index.js

@@ -320,6 +320,16 @@ Db.prototype.createQuery = function () {
   return new Query(this);
 };
 
+/**
+ * Create a create query.
+ *
+ * @return {Query} The query instance.
+ */
+Db.prototype.create = function () {
+  var query = this.createQuery();
+  return query.create.apply(query, arguments);
+};
+
 /**
  * Create a select query.
  *

lib/db/statement.js

@@ -330,7 +330,16 @@ Statement.prototype.buildStatement = function () {
   if (state.from && state.from.length) {
     statement.push('FROM');
     statement.push(state.from.map(function (item) {
-      if (typeof item === 'string') {
+      if (typeof item === 'function') {
+        var child = new Statement(self.db);
+        child._state.paramIndex = self._state.paramIndex;
+        item(child);
+        return '(' + child.toString() + ')';
+      }
+      else if (item instanceof Statement) {
+        return '(' + item.toString() + ')';
+      }
+      else if (typeof item === 'string') {
         return item;
       }
       else {

test/db/statement-test.js

@@ -180,6 +180,16 @@ COMMIT \n\
       this.statement.select().from('(SELECT * FROM OUser)');
       this.statement.buildStatement().should.equal('SELECT * FROM (SELECT * FROM OUser)');
     });
+    it('should select from a subquery', function () {
+      this.statement.select().from((new Statement(this.db).select().from('OUser')));
+      this.statement.buildStatement().should.equal('SELECT * FROM (SELECT * FROM OUser)');
+    });
+    it('should select from a subquery, using a function', function () {
+      this.statement.select().from(function (s) {
+        s.select().from('OUser');
+      });
+      this.statement.buildStatement().should.equal('SELECT * FROM (SELECT * FROM OUser)');
+    });
   });
 
   describe('Statement::to()', function () {