急！！！sql绑定到datagrid中不显示（使用其他sql语句可以显示）

sql = "SELECT a.upps as 隐患上传部门, a.istop as 一线员工人数, a.titletotal as 问题或建议总数, b.canyu as 一线员工参与人数, LTRIM(CONVERT(NUMERIC(9, 2), b.canyu * 100.0 / a.istop)) + '%' AS 参与度"
+"FROM (SELECT upps, istop, COUNT(company) AS titletotal FROM allpro WHERE (istop <> 0) GROUP BY upps, istop) AS a LEFT OUTER JOIN"
+" (SELECT upps, COUNT(DISTINCT person1) AS canyu FROM allpro WHERE (position = '一线员工') GROUP BY upps) AS b ON a.upps = b.upps";

SQL语句里面缺少必要的空格