sql语句错误一

sql语句错误一

select * from ticketinstance as t
 left outer join batch on t.Col_Batch = batch.Col_ObjId
 left outer join ticket on t.Col_ObjId = ticket.Col_ObjId
 where t.Col_ObjId =2 and Col_Batch = 2

正确

select * from ticketinstance as 't'
 left outer join batch on t.Col_Batch = batch.Col_ObjId
 left outer join ticket on t.Col_ObjId = ticket.Col_ObjId
 where t.Col_ObjId =2 and Col_Batch = 2

错误