where trim(translate(col,'0123456789.',' ')) is null;
显示10个字段且显示是重复数据,不用GROUP BY 分组,可有其他更好的方法。谢谢
GROUP BY 为何不支持 如 group by *
group by * 有什么意义
如果取n个字段,那不是把n 个字段都写在group by内,这是不是会造成sql语句效率低呢
取 a,b,c,d,e,f,g...字段想在group by 只用 a,c,d进行分组显示列表数据 select a,b,c,d,e,f,g... from t1,t2,t3 where t1.id = t2.id,t1.id2=t3.id2 group by a,c,d having(count(*))>1 提示缺少表达式
分组显示不能这样实现。 try: select a,b,c,d,e,f,g... from t1,t2,t3 where t1.id = t2.id,t1.id2=t3.id2 union select distinct a,c,d from t1,t2,t3;
sorry!try: select a,c,d,b,e,..from t1,t2,t3 where t1.id = t2.id,t1.id2=t3.id2 union select distinct a,c,d,'','','',... from t1,t2,t3;
select a,b,c,d,e,f,g... from t1,t2,t3
where t1.id = t2.id,t1.id2=t3.id2
group by a,c,d having(count(*))>1 提示缺少表达式
try:
select a,b,c,d,e,f,g... from t1,t2,t3
where t1.id = t2.id,t1.id2=t3.id2
union
select distinct a,c,d from t1,t2,t3;
select a,c,d,b,e,..from t1,t2,t3
where t1.id = t2.id,t1.id2=t3.id2
union
select distinct a,c,d,'','','',... from t1,t2,t3;
oracle有没有 StringBuffer这个函数。
因为定义一个函数返回的是string,提示字符文体中字符太多,何有解决。 谢谢