I want to add some variable to char array while creating it. How can I do this? sqlite3_prepare_v2
need char[]
. thanks
unsigned int keyid = 10;
char buffer2[] = "SELECT * FROM table WHERE id = " + keyid; // problem (convert to char and merge)
sqlite3_prepare_v2(db, buffer2, strlen(buffer2), &stmt, 0);
Put the string inside a string
:)
std::string buffer2 = "SELECT * FROM table WHERE id = " + std::to_string(keyid);
sqlite3_prepare_v2(db, buffer2.c_str(), buffer2.length(), &stmt, 0);
You should be binding your parameter instead. This also prevents any potential for SQL injection attacks.
unsigned int keyid = 10;
const char buffer2[] = "SELECT * FROM table WHERE id = ?";
sqlite3_prepare_v2(db, buffer2, -1, &stmt, 0);
sqlite3_bind_int(&stmt, 1, keyid);
Well the most obvious solution for C++ is to use std::string
std::string buffer2 = "SELECT * FROM table WHERE id = " + std::to_string(keyid);
sqlite3_prepare_v2(db, buffer2.c_str() , buffer2.size() , &stmt, 0);
You could stream the different types since you are using C++
#include <sstream>
//...
std::stringstream buffer2;
buffer2 << "SELECT * FROM table WHERE id = " << keyid;
and then use the string's c_str
where ac style string is needed.
buffer2.str().c_str()'
but since this is SQL, using parameters in your query is much better.
Look into sprintf, eg
sprintf(buffer2, "SELECT * FROM table WHERE id = %d", keyID);
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.