remove skipUselessParentheses

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/parsing/lexer/LexerEngine.java

@@ -96,14 +96,6 @@ public final class LexerEngine {
         return result.toString();
     }
     
-    /**
-     * 跳过无用的嵌套小括号.
-     */
-    public void skipUselessParentheses() {
-        while (skipIfEqual(Symbol.LEFT_PAREN)) { }
-        while (skipIfEqual(Symbol.RIGHT_PAREN)) { }
-    }
-    
     /**
      * 断言当前词法标记类型与传入值相等并跳过.
      *

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/parsing/parser/statement/dql/select/AbstractSelectParser.java

@@ -108,9 +108,7 @@ public abstract class AbstractSelectParser implements SQLStatementParser {
     
     private void parseTable(final SelectStatement selectStatement) {
         if (lexerEngine.skipIfEqual(Symbol.LEFT_PAREN)) {
-            lexerEngine.skipUselessParentheses();
             selectStatement.setSubQueryStatement(parseInternal());
-            lexerEngine.skipUselessParentheses();
             if (lexerEngine.equalAny(DefaultKeyword.WHERE, Assist.END)) {
                 return;
             }

sharding-jdbc-core/src/test/resources/sql/dql/select_sub_query.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <sqls>
-    <sql id="assertSelectSubQuerySingleTableWithParentheses" value="SELECT t.* FROM ((SELECT o.* FROM t_order o WHERE o.order_id IN (%s, %s))) t ORDER BY t.order_id" type="MySQL,PostgreSQL,SQLServer,Oracle" />
-    <sql id="assertSelectSubQueryMultiTableWithParentheses" value="SELECT t.* FROM ((SELECT i.* FROM t_order o, t_order_item i WHERE o.order_id = i.order_id and o.order_id IN (%s, %s))) t ORDER BY t.item_id" type="MySQL,PostgreSQL,SQLServer,Oracle" />
+    <sql id="assertSelectSubQuerySingleTableWithParentheses" value="SELECT t.* FROM (SELECT o.* FROM t_order o WHERE o.order_id IN (%s, %s)) t ORDER BY t.order_id" type="MySQL,PostgreSQL,SQLServer,Oracle" />
+    <sql id="assertSelectSubQueryMultiTableWithParentheses" value="SELECT t.* FROM (SELECT i.* FROM t_order o, t_order_item i WHERE o.order_id = i.order_id and o.order_id IN (%s, %s)) t ORDER BY t.item_id" type="MySQL,PostgreSQL,SQLServer,Oracle" />
     <sql id="assertSelectSubQueryWithOrderBy" value="SELECT COUNT(1) as orders_count FROM (SELECT * FROM t_order ORDER BY order_id desc) t" type="MySQL,PostgreSQL,Oracle" />
     <sql id="assertSelectSubQueryWithGroupBy" value="SELECT COUNT(1) as order_items_count FROM (SELECT order_id FROM t_order_item GROUP BY order_id) t" type="MySQL,PostgreSQL,Oracle" />
 </sqls>