语句1:select vin, engineno from syjk_ccs_rkmx group by vin, engineno haiving count(vin)=1;
语句2:select * from syjk_ccs_rkmx
where (vin, engineno) in
(select vin, engineno from syjk_ccs_rkmx group by vin, engineno haiving count(vin)=1);
语句1:select vin, engineno from syjk_ccs_rkmx group by vin, engineno haiving count(vin)=1; 语句2:select * from syjk_ccs_rkmx where (vin, engineno) in (select vin, engineno from syjk_ccs_rkmx group by vin, engineno haiving count(vin)=1); 问题: 语句1 能够查询出数据,而
select * from syjk_ccs_rkmx as t1
where (t1.vin, t1.engineno) in
(select t2.vin, t2.engineno from syjk_ccs_rkmx as t2 group by t2.vin, t2.engineno haiving count(t2.vin)=1);