我试图将C++连接到MySql，但无法正常工作。我从Oracle网站使用Windows的最新MySql和C++/Connector。我也使用VS2010。

它可以编译，并且除了getString之外，其他所有方法都可以正常工作!我使用了他们提供的一些调整示例:

#include "stdafx.h"


#include <stdlib.h>
#include <iostream>
#include <sstream>
#include <stdexcept>

#include <driver/mysql_public_iface.h>

#include "examples.h"

using namespace std;

int main(int argc, const char **argv)
{
string url(argc >= 2 ? argv[1] : EXAMPLE_HOST);
const string user(argc >= 3 ? argv[2] : EXAMPLE_USER);
const string pass(argc >= 4 ? argv[3] : EXAMPLE_PASS);
const string database(argc >= 5 ? argv[4] : EXAMPLE_DB);

/* sql::ResultSet.rowsCount() returns size_t */
size_t row;
stringstream sql;
stringstream msg;
int i, affected_rows;

cout << boolalpha;
cout << "1..1" << endl;
cout << "# Connector/C++ connect basic usage example.." << endl;
cout << "#" << endl;

try {
    sql::Driver * driver = sql::mysql::get_driver_instance();
    /* Using the Driver to create a connection */
    std::auto_ptr< sql::Connection > con(driver->connect("localhost", "root", "root"));

    /* Creating a "simple" statement - "simple" = not a prepared statement */
    std::auto_ptr< sql::Statement > stmt(con->createStatement());

    /* Create a test table demonstrating the use of sql::Statement.execute() */
    stmt->execute("USE publications");
    cout << "#\t Test table created" << endl;

    /* Populate the test table with data */

    cout << "#\t Test table populated" << endl;

    {
        /*
        Run a query which returns exactly one result set like SELECT
        Stored procedures (CALL) may return more than one result set
        */
        std::auto_ptr< sql::ResultSet > res(stmt->executeQuery("SELECT id, task FROM to_do_list ORDER BY id ASC"));
        cout << "#\t Running 'SELECT id, task FROM to_do_list ORDER BY id ASC'" << endl;

        /* Number of rows in the result set */
        cout << "#\t\t Number of rows\t";
        cout << "res->rowsCount() = " << res->rowsCount() << endl;
        if (res->rowsCount() != EXAMPLE_NUM_TEST_ROWS) {
            msg.str("");
            msg << "Expecting " << EXAMPLE_NUM_TEST_ROWS << "rows, found " << res->rowsCount();
            throw runtime_error(msg.str());
        }

        /* Fetching data */
        row = 0;
        while (res->next()) {
            cout << "#\t\t Fetching row " << row << "\t";
            /* You can use either numeric offsets... */
            cout << "id = " << res->getInt("id");
            /* ... or column names for accessing results. The latter is recommended. */
            cout << ", task = '" << res->getString("task") << "'" << endl;
            row++;
            system("PAUSE");
        }
    }

1..1
# Connector/C++ connect basic usage example..
#
#        Test table created
#        Test table populated
#        Running 'SELECT id, task FROM to_do_list ORDER BY id ASC'
#                Number of rows res->rowsCount() = 4
#                Fetching row 0 id = 3, task = ''
Press any key to continue . . .
#                Fetching row 1 id = 7, task = ''
Press any key to continue . . .
   ☼   Ñ╤½x R=  I>             ☼   £I> task  ↕ 4å@ xQ@ ♦   ☼   ☻    ocalhost ½xÇ
'
Press any key to continue . . .

mysql> use publications
Database changed
mysql> select id, task from to_do_list;
+----+---------------------------+
| id | task                      |
+----+---------------------------+
|  9 | prepare for calculus      |
|  3 | buy jeans                 |
|  8 | buy new scale             |
|  7 | buy Ethics book for class |
+----+---------------------------+
4 rows in set (0.00 sec)

msvcp90d.dll!104e8dcb()
[Frames below may be incorrect and/or missing, no symbols loaded for msvcp90d.dll]
try_mysql_native.exe!std::operator<<(std::basic_ostream > & os={...}, const sql::SQLString & str={...}) Line 196 + 0x1f bytes C++ try_mysql_native.exe!main(int argc=1, const char * * argv=0x003e63e8) Line 115 + 0xa5 bytes C++ try_mysql_native.exe!__tmainCRTStartup() Line 586 + 0x19 bytes C try_mysql_native.exe!mainCRTStartup() Line 403 C kernel32.dll!7c817077()

最佳答案

您确定任务栏没有设置二进制排序规则吗？如果是这样，连接器可能会为同一列返回不同的元数据。

更新:

另外，请检查连接器是否已使用与项目相同的运行时进行编译。如果使用VS，我敢打赌另一个是用/MT编译的，另一个是用/MD编译的。这样，他们使用不同的堆，将无法正常工作。

关于c++ - MySql C++连接器getString()不能正常工作，而getInt可以正常工作，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/4822958/