Oracle ÊÓͼ ÎÊÌâ
SQL> create view c as
2 select nvl(a.n1,b.n1),nvl(a.n2,b.n2),n3,n4 from a full join b
3 on a.n1=b.n1 and a.n2=b.n2;
select nvl(a.n1,b.n1),nvl(a.n2,b.n2),n3,n4 from a full join b
*
ERROR at line 2:
ORA-00998: must name this expression with a column alias
лл ¸ÄÁË
ORA-00998: must name this expression with a column alias
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