Oracle某表某字段存在空值,如何将其属性强制为“非空"?
什么意思?如果要将该字段加上非空约束
SQL> create table tttt as select 1 id,2 num from dual
2 union all select 2,null from dual;
Table created
SQL> alter table tttt modify num not null;
alter table tttt modify num not null
ORA-02296: 无法启用 (W.) - 找到空值
SQL> alter table tttt modify num not null enable novalidate;
Table altered
SQL> insert into tttt values(3,null);
insert into tttt values(3,null)
ORA-01400: 无法将 NULL 插入 ("W"."TTTT"."NUM")
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转载自panshaobinsb.iteye.com/blog/1597431
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