code: public String selectByExample(MappedStatement ms) {
          Class<?> entityClass = getEntityClass(ms);
          //将返回值修改为实体类型
          setResultType(ms, entityClass);
          StringBuilder sql = new StringBuilder("SELECT ");
          if (isCheckExampleEntityClass()) {
              sql.append(SqlHelper.exampleCheck(entityClass));
          }
          sql.append("<if test=\"distinct\">distinct</if>");
          //支持查询指定列
          sql.append(SqlHelper.exampleSelectColumns(entityClass));
          sql.append(SqlHelper.fromTable(entityClass, tableName(entityClass)));
          sql.append(SqlHelper.exampleWhereClause());
          sql.append(SqlHelper.exampleOrderBy(entityClass));
          sql.append(SqlHelper.exampleForUpdate());
          return sql.toString();
      }
docs: 根据Example查询
  
  @param ms
  @return