Fix grammar bugs

DataStorage/Database/DataMapperAbstract.php

@@ -2239,11 +2239,14 @@ class DataMapperAbstract implements DataMapperInterface
      */
     public static function getPrimaryKeyBy($refKey, string $ref) : array
     {
-        $query = self::getQuery();
-        $query->select(static::$primaryField)
+        $query = new Builder(self::$db);
+        $query->prefix(self::$db->getPrefix())
+            ->select(static::$table . '.' . static::$primaryField)
             ->from(static::$table)
             ->where(static::$table . '.' . $ref, '=', $refKey);
 
+        var_dump($query->toSql());
+
         $sth = self::$db->con->prepare($query->toSql());
         $sth->execute();
 
@@ -2493,6 +2496,6 @@ class DataMapperAbstract implements DataMapperInterface
             }
         }
 
-        throw \Exception();
+        throw new \Exception('Invalid member name');
     }
 }

DataStorage/Database/GrammarAbstract.php

@@ -172,7 +172,7 @@ abstract class GrammarAbstract
 
         foreach ($elements as $key => $element) {
             if (is_string($element) && $element !== '*') {
-                if(strpos($element, '.')) {
+                if(strpos($element, '.') === false) {
                     $prefix = '';
                 }
 
@@ -191,6 +191,37 @@ abstract class GrammarAbstract
         return rtrim($expression, ', ');
     }
 
+    /**
+     * Expressionize elements.
+     *
+     * @param array  $elements Elements
+     * @param string $prefix   Prefix for table
+     *
+     * @return string
+     *
+     * @since  1.0.0
+     */
+    protected function expressionizeTable(array $elements, string $prefix = '') : string
+    {
+        $expression = '';
+
+        foreach ($elements as $key => $element) {
+            if (is_string($element) && $element !== '*') {
+                $expression .= $this->compileSystem($element, $prefix) . ', ';
+            } elseif (is_string($element) && $element === '*') {
+                $expression .= '*, ';
+            } elseif ($element instanceof \Closure) {
+                $expression .= $element() . ', ';
+            } elseif ($element instanceof BuilderAbstract) {
+                $expression .= $element->toSql() . ', ';
+            } else {
+                throw new \InvalidArgumentException();
+            }
+        }
+
+        return rtrim($expression, ', ');
+    }
+
     /**
      * Compile system.
      *

DataStorage/Database/Query/Grammar/Grammar.php

@@ -169,7 +169,7 @@ class Grammar extends GrammarAbstract
      */
     protected function compileFrom(Builder $query, array $table) : string
     {
-        $expression = $this->expressionizeTableColumn($table, $query->getPrefix());
+        $expression = $this->expressionizeTable($table, $query->getPrefix());
 
         if ($expression === '') {
             return '';