A.Its members adopt a common currency.
B.Its members have a common economic policy.
C.It removes barriers to imports and exports among its members.
[单选题]Four countries operate within a customs union. One country proposes moving
[试题]union和union all有什么不同?
[多选题] 有关union和union all,以下说法正确的是()A . union比union all多执行了distinct操作B . 两者查询返回的结果集一样C . 两者效率一样D . union all可以代替inner join使用
[试题]union和union all有什么不同?查出比经理薪水还高的员工信息:
[多选题] 可以使用UNION子句的语句()A . INSERTB . SELECTC . CREATEVIEWD . FOR
[单选题]In a purely competitive market, economic losses indicate that:A.Price is be
[试题]下面对 union 的描述正确的是( )A.union 只连接结果集完全一样的查询语句B.union 可以连接结果集中数据类型个数相同的多个结果集C.union 是筛选关键词,对结果集再进行操作D.任何查询语句都可以用 union 来连接
[单选题]已知: union { int i; char c; float a; }st;则sizeof(st)的值是______。A.4B.5C.6D.7
[主观题]struct w{ char low;char high;};union u{ struct w byte;short word;}uw;main( ){ int result;uw.word=0x1234;printf(“word value:%04x/n”,uw.word);printf(“high byte:%02x/n”,uw.byte.high);printf(“low byte:%02x/n”,uw.byte.low);uw.byte.low=0x74;printf(“word va
[单选题]有以下程序:main(){ union{ unsigned int n; unsigned char c; }u1; u1.c='A'; printf("%c/n",u1.n);}执行后输出结果是( )。A.产生语法错B.随机值C.AD.65