带有c/c++的SQLite数据库

SQLite database with c/c++

本文关键字：SQLite 数据库 c++ 带有      更新时间：2023-10-16

如何修复此错误

/home/andi/Desktop/latihan/sqlite c++/sqlite insert.cpp:37:76: error: invalid operands of types ‘const char [53]’ and ‘char [50]’ to binary ‘operator+’

这就是代码。我希望我的代码可读，很抱歉我的英语不好

# include <stdio.h>
# include <iostream>
# include <sqlite3.h>
# include <stdlib.h>
using namespace std;
int main(void)
{
sqlite3 *conn;
sqlite3_stmt *res;
int     error = 0;
int     rec_count = 0;
const char     *errMSG;
const char     *tail;
char sql_lite[900]=" ";
int x,number;
char name[50];
char username[50];
char password[50];
error = sqlite3_open("data.dat", &conn);
if (error)
{
printf("Can not open database");
}

printf("Enter the number of data to be insertedn");
scanf("%d",&x);
for(number=x;number>0;number--) 
{ 
cout<<"name : ";cin>>name;
cout<<"username : ";cin>>username;
cout<<"password : ";cin>>password;
}
sprintf(sql_lite, "INSERT INTO login (name,username,password) VALUES ('"+ username + "','" + name + "','" +  password +"');"); 
error = sqlite3_exec(conn, sql_lite, 0, 0, 0);
error = sqlite3_prepare_v2(conn, "SELECT * FROM login order by No",1000, &res, &tail);

if (error != SQLITE_OK)
{
printf("We did not get any data!");
exit(0);
}
printf("=======================================n");
while (sqlite3_step(res) == SQLITE_ROW)
{
printf("%d|", sqlite3_column_int(res, 0));
printf("%s|", sqlite3_column_text(res, 1));
printf("%s|", sqlite3_column_text(res, 2));
printf("%s|", sqlite3_column_text(res, 3));
printf("%un", sqlite3_column_int(res, 4));

rec_count++;
}
printf("=======================================n");
printf("We received %d records.nTotal rows=%dn",rec_count,SQLITE_ROW);
sqlite3_finalize(res);
sqlite3_close(conn);
return 0;
}

这里的问题与SQL无关。不能将+运算符用于char数组串联。为此，您必须使用sprintf。参见以下示例

  char buffer [50];
  char* a="aaaa", b="bbbbbbb";
  sprintf (buffer, "%s plus %s , a, b);

但是，如果您使用C++编程，我建议您使用std::string而不是char数组。

如何使用字符串

#include <iostream>
#include <string>
int main()
{
    std::string name="",username="",password="";
    std::cout << "name : "; std::cin >> name;
    std::cout << "username : "; std::cin >> username;
    std::cout << "password : "; std::cin >> password;  
    std::string query = "INSERT INTO login (name,username,password) VALUES ('" + username + "','" + name + "','" + password + "');";
    std::cout << query << std::endl;
    return 0;
}
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