为什么
SELECT c.* FROM CUSTOMER WHERE CUSTOMER_NAME like '%汕头市奔腾科技有限公司%' and (CUSTOMER.pkcorp='1081' or customer.customer_pk in (select customer_pk from customermaster where pkcorp = '1081'));
结果一条记录;
SELECT c.* FROM CUSTOMER c,customermaster cm where c.CUSTOMER_NAME like '%汕头市奔腾科技有限公司%' and (c.pkcorp='1081' or (c.customer_pk=cm.customer_pk and cm.pkcorp='1081'));
结果68万条记录;(customermaster这个表正好一共68万条记录)
小弟比较初级,麻烦同志们帮忙解释一下,再次谢过了。
SELECT c.* FROM CUSTOMER WHERE CUSTOMER_NAME like '%汕头市奔腾科技有限公司%' and (CUSTOMER.pkcorp='1081' or customer.customer_pk in (select customer_pk from customermaster where pkcorp = '1081'));
结果一条记录;
SELECT c.* FROM CUSTOMER c,customermaster cm where c.CUSTOMER_NAME like '%汕头市奔腾科技有限公司%' and (c.pkcorp='1081' or (c.customer_pk=cm.customer_pk and cm.pkcorp='1081'));
结果68万条记录;(customermaster这个表正好一共68万条记录)
小弟比较初级,麻烦同志们帮忙解释一下,再次谢过了。
解决方案 »
- ORACLE或者hibernate高手快来哦。。。。
- 数据文件出错
- 十万火急!ORACLE9i经常报Ora-06502,ora-06512错误
- 求sql:根据表的一个字段合并记录
- 关于jdbc的Oracle连接
- 有关oracle的数据库连接打database link的问题,请指教THANKS?
- 如果在一个存储过程里调用另一个存储过程,在线等,马上结贴
- 请教nomount、mount和open的区别,谢谢
- 请教一个性能的问题:
- 可是我如果两台机器都装win2k advance server,用oracle能做C/S模式么
- oracle 导入库时报错 IMP-00003: 遇到 ORACLE 错误 1115
- oracle10G统计表如何进行快速拆分?
应该是
SELECT * FROM CUSTOMER WHERE CUSTOMER_NAME like '%汕头市奔腾科技有限公司%' and (CUSTOMER.pkcorp='1081' or customer.customer_pk in (select customer_pk from customermaster where pkcorp = '1081'));
你的第二个的结果说明:
CUSTOMER表中存在一条CUSTOMER_NAME like '%汕头市奔腾科技有限公司%' and pkcorp='1081'的记录
如果
CUSTOMER表中存在两条CUSTOMER_NAME like '%汕头市奔腾科技有限公司%' and pkcorp='1081'的记录
则你的结果应是68W*2条记录