单引号需要用双引号包括起来(" ' ")不然条件会失效
sql = "select * from user where createdtime='"+ "%s" %created_time + "'" + " group by username;"
单引号需要用双引号包括起来(" ' ")不然条件会失效
sql = "select * from user where createdtime='"+ "%s" %created_time + "'" + " group by username;"