我有一张表如下:
emp_name emp_address sex matial_status
uuuu eee m s
iiii iii f s
uuuu eee m s
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我想基于3个字段emp_name,emp_address和sex删除重复的条目.我的结果表(在删除重复之后)应该看起来像 -
emp_name emp_address sex marital_status
uuuu eee m s
iiii iii f s
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我无法回想起如何为此编写SQL查询.有人帮忙吗?
我必须消除字符串1中出现的字符串2,并找到两个字符串的交集.
这是我尝试过的:
#include "stdafx.h"
#include "stdio.h"
#include "conio.h"
#include "string.h"
class operation
{
public:
char string1[100];
char string2[50];
operation(){};
operation(char a[100], char b[50]);
operation operator+(operation);
operation operator-(operation);
operation operator*(operation);
};
operation::operation(char a[100], char b[50])
{
strcpy(string1, a);
strcpy(string2, b);
}
operation operation::operator +(operation param)
{
operation temp;
strcpy(param.string1, temp.string1);
strcpy(param.string2, temp.string2);
strcat(temp.string1, temp.string2);
return (temp);
}
operation operation::operator -(operation param)
{
operation temp;
strcpy(param.string1, temp.string1);
strcpy(param.string2, temp.string2) ;
for (int i = 0; i<strlen(temp.string2); i++)
{
temp.string1.erase(i, 1);
}
return …Run Code Online (Sandbox Code Playgroud)