MySQL_Exception

Table 'science_psciDB.acc_school' doesn't exist

SELECT reg_step2.* ,acc_school.name_sc,acc_school.name_sc2,acc_school.belong_sc,school_group.schGroupName 
					 ,reg_score.Score1,reg_score.Score2,reg_score.Score3,reg_score.Score4,reg_score.Score5 ,reg_score.Total ,reg_score.Result,reg_score.ResultNo
 					FROM reg_step2 
 					left Join acc_school ON reg_step2.id_sc = acc_school.id_sc 
					left Join school_group ON acc_school.schGroupCode = school_group.schGroupCode 
					left Join reg_score ON reg_step2.regStep2ID = reg_score.regStep2ID
					where   reg_step2.subID='18'   
					order by  reg_score.Total desc,reg_step2.id_sc