diff --git a/SQLBuilder/Universal/Query/SelectQuery.php b/SQLBuilder/Universal/Query/SelectQuery.php
index ac325af..57a37a5 100644
--- a/SQLBuilder/Universal/Query/SelectQuery.php
+++ b/SQLBuilder/Universal/Query/SelectQuery.php
@@ -206,7 +206,7 @@ public function groupBy($expr, array $modifiers = null)
         return $this;
     }
 
-    public function clearGroupBy()
+    public function removeGroupBy()
     {
         $this->groupByList = array();
     }
@@ -263,36 +263,42 @@ public function buildSelectClause(BaseDriver $driver, ArgumentArray $args)
         return $sql;
     }
 
-    public function buildFromClause(BaseDriver $driver, ArgumentArray $args)
+    protected function buildFromClauseMySQL(BaseDriver $driver, ArgumentArray $args)
     {
         $tableRefs = array();
-        if ($driver instanceof MySQLDriver) {
-            foreach ($this->from as $k => $v) {
-                /* "column AS alias" OR just "column" */
-                if (is_string($k)) {
-                    $sql = $driver->quoteTable($k).' AS '.$v;
-                    if ($this->definedIndexHint($v)) {
-                        $sql .= $this->buildIndexHintClauseByTableRef($v, $driver, $args);
-                    } elseif ($this->definedIndexHint($k)) {
-                        $sql .= $this->buildIndexHintClauseByTableRef($k, $driver, $args);
-                    }
-                    $tableRefs[] = $sql;
-                } else if (is_integer($k) || is_numeric($k)) {
-                    $sql = $driver->quoteTable($v);
-                    if ($this->definedIndexHint($v)) {
-                        $sql .= $this->buildIndexHintClauseByTableRef($v, $driver, $args);
-                    }
-                    $tableRefs[] = $sql;
+        foreach ($this->from as $k => $v) {
+            /* "column AS alias" OR just "column" */
+            if (is_string($k)) {
+                $sql = $driver->quoteTable($k).' AS '.$v;
+                if ($this->definedIndexHint($v)) {
+                    $sql .= $this->buildIndexHintClauseByTableRef($v, $driver, $args);
+                } elseif ($this->definedIndexHint($k)) {
+                    $sql .= $this->buildIndexHintClauseByTableRef($k, $driver, $args);
                 }
-            }
-        } else {
-            foreach ($this->from as $k => $v) {
-                /* "column AS alias" OR just "column" */
-                if (is_string($k)) {
-                    $tableRefs[] = $driver->quoteTable($k).' AS '.$v;
-                } elseif (is_integer($k) || is_numeric($k)) {
-                    $tableRefs[] = $driver->quoteTable($v);
+                $tableRefs[] = $sql;
+            } else if (is_integer($k) || is_numeric($k)) {
+                $sql = $driver->quoteTable($v);
+                if ($this->definedIndexHint($v)) {
+                    $sql .= $this->buildIndexHintClauseByTableRef($v, $driver, $args);
                 }
+                $tableRefs[] = $sql;
+            }
+        }
+        if (!empty($tableRefs)) {
+            return ' FROM '.join(', ', $tableRefs);
+        }
+        return '';
+    }
+
+    protected function buildFromClause(BaseDriver $driver, ArgumentArray $args)
+    {
+        $tableRefs = array();
+        foreach ($this->from as $k => $v) {
+            /* "column AS alias" OR just "column" */
+            if (is_string($k)) {
+                $tableRefs[] = $driver->quoteTable($k).' AS '.$v;
+            } elseif (is_integer($k) || is_numeric($k)) {
+                $tableRefs[] = $driver->quoteTable($v);
             }
         }
         if (!empty($tableRefs)) {
@@ -324,7 +330,7 @@ public function buildGroupByClause(BaseDriver $driver, ArgumentArray $args)
         return $sql;
     }
 
-    public function buildLockModifierClause()
+    public function buildLockModifierClauseMySQL()
     {
         if ($this->lockModifier) {
             return ' '.$this->lockModifier;
@@ -343,18 +349,31 @@ public function buildHavingClause(BaseDriver $driver, ArgumentArray $args)
 
     public function toSql(BaseDriver $driver, ArgumentArray $args)
     {
+        if ($driver instanceof MySQLDriver) {
+            return 'SELECT'
+                .$this->buildOptionClause()
+                .$this->buildSelectClause($driver, $args)
+                .$this->buildFromClauseMySQL($driver, $args)
+                .$this->buildPartitionClause($driver, $args)
+                .$this->buildJoinClause($driver, $args)
+                .$this->buildWhereClause($driver, $args)
+                .$this->buildGroupByClause($driver, $args)
+                .$this->buildHavingClause($driver, $args)
+                .$this->buildOrderByClause($driver, $args)
+                .$this->buildPagingClause($driver, $args)
+                .$this->buildLockModifierClauseMySQL()
+                ;
+        }
         return 'SELECT'
             .$this->buildOptionClause()
             .$this->buildSelectClause($driver, $args)
             .$this->buildFromClause($driver, $args)
-            .$this->buildPartitionClause($driver, $args)
             .$this->buildJoinClause($driver, $args)
             .$this->buildWhereClause($driver, $args)
             .$this->buildGroupByClause($driver, $args)
             .$this->buildHavingClause($driver, $args)
             .$this->buildOrderByClause($driver, $args)
             .$this->buildPagingClause($driver, $args)
-            .$this->buildLockModifierClause()
             ;
     }
 
diff --git a/SQLBuilder/Universal/Traits/OptionTrait.php b/SQLBuilder/Universal/Traits/OptionTrait.php
index f0fd70a..a0422d0 100644
--- a/SQLBuilder/Universal/Traits/OptionTrait.php
+++ b/SQLBuilder/Universal/Traits/OptionTrait.php
@@ -41,8 +41,6 @@ public function buildOptionClause()
         if (empty($this->options)) {
             return '';
         }
-        $sql = ' '.implode(' ', $this->options);
-
-        return $sql;
+        return ' '.join(' ', $this->options);
     }
 }