如何从字符串C ++向sqlite表插入数据？

Question

I was trying to get some data from user and insert it to sql table. I thought it might be smtg like that but it does not work. Please tell me how can I add entered in console data to sqlite table?

    string s;
    getline(cin, s);
    cout << s << endl;

    sql = "INSERT INTO Contracts (ID_Con, ID_Shop, ID_Ven, PRICE) "  \
    "VALUES ('%s', s);"; 

/* Execute SQL statement */
   rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);
   if( rc != SQLITE_OK ){
      fprintf(stderr, "SQL error: %s\n", zErrMsg);
      sqlite3_free(zErrMsg);
   }else{
      fprintf(stdout, "Records created successfully\n");
   }

I thought I can write 1001,2004,5001,50.4 and it will be inputed to "VALUES ('%s', s);" but it doesn't. Please help

Answer 1

You can't do parameterised insertion into a string, as you have tried here, in a string assignment operator in C++. There are a number of other ways of doing it.

You could allocate an old-fashioned C string, and use a sprintf call to substitute your string variable into the resulting string using a %s placeholder.

But I'd probably use a C++ ostringstream to build your string in a more readable way, without all the format string hieroglyphics. Something like this should do the trick for the example you have above (assuming you have already declared sql as a string):

#include <sstream>

...

string s;
getline(cin, s);
cout << s << endl;

ostringstream oss;

oss << "INSERT INTO Contracts (ID_Con, ID_Shop, ID_Ven, PRICE) "
    << "VALUES ("
    << s
    << ");" ; 

sql = oss.str();