[TOC] ### mappedStatement 對應xml文件中的某一sql節點的封裝   ### BoundSql 對應xml文件中的某一sql節點的sql語句的封裝，表示動態生成的SQL語句以及相應的參數信息 當調用SqlSource的getBoundSql方法，傳入的就是parameterMappings相對應的參數,最終生成BoundSql對象,有了BoundSql就可以執行sql語句了  生成BoundSql ~~~ conn = sqlSession.getConfiguration().getEnvironment().getDataSource().getConnection(); ps = conn.prepareStatement(countSql); BoundSql cntBoundSql = new BoundSql(mappedStatement.getConfiguration(), countSql, boundSql.getParameterMappings(), parameter); ReflectHelper.copyFieldValue(boundSql, cntBoundSql, "additionalParameters"); ReflectHelper.copyFieldValue(boundSql, cntBoundSql, "metaParameters"); ParameterHandler parameterHandler = new DefaultParameterHandler(mappedStatement, parameter, cntBoundSql); parameterHandler.setParameters(ps); rs = ps.executeQuery(); if (rs.next()) { int var13 = rs.getInt(1); return var13; ~~~