Question

大家。我想使用C ++连接Mysql，但它不起作用：错误信息是：

error LNK2019: unresolved external symbol "__declspec(dllimport) public: char const * __thiscall sql::SQLString::c_str(void)const " (__imp_?c_str@SQLString@sql@@QBEPBDXZ) referenced in function __catch$?RunConnectMySQL@@YAXXZ$0
error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall sql::SQLString::~SQLString(void)" (__imp_??1SQLString@sql@@QAE@XZ) referenced in function "void __cdecl RunConnectMySQL(void)" (?RunConnectMySQL@@YAXXZ)
error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall sql::SQLString::SQLString(char const * const)" (__imp_??0SQLString@sql@@QAE@QBD@Z) referenced in function "void __cdecl RunConnectMySQL(void)" (?RunConnectMySQL@@YAXXZ)
error LNK2019: unresolved external symbol "__declspec(dllimport) class sql::mysql::MySQL_Driver * __cdecl sql::mysql::get_driver_instance(void)" (__imp_?get_driver_instance@mysql@sql@@YAPAVMySQL_Driver@12@XZ) referenced in function "class sql::mysql::MySQL_Driver * __cdecl sql::mysql::get_mysql_driver_instance(void)" (?get_mysql_driver_instance@mysql@sql@@YAPAVMySQL_Driver@12@XZ)

我在stackoverflow中搜索了同样的问题，但它没有正确的答案。我的代码是：

#include <iostream>
#include <string>
#include <mysql_connection.h>
#include <mysql_driver.h>
#include <cppconn/driver.h>
#include <cppconn/exception.h>
#include <cppconn/resultset.h>
#include <cppconn/statement.h>
#include <cppconn/prepared_statement.h>
using namespace std;

void RunConnectMySQL()
{
    sql::mysql::MySQL_Driver *driver = NULL;
    sql::Connection *con = NULL; 
    Statement *state = NULL;
    ResultSet *result = NULL;
    try
    {
        driver = sql::mysql::get_mysql_driver_instance();
        con = driver->connect("tcp://127.0.0.1:3306","root","");
        state = con->createStatement();
        state->execute("use monitor");
        result = state->executeQuery("select * from address");
    }
    catch(sql::SQLException & ex)
    {
        cout<<ex.what()<<endl;
        return;
    }

    while(result->next())
    {
        cout<<"source: "<<result->getString("source").c_str()<<endl;
    }
    state->close();
}

int main()
{
    RunConnectMySQL();
    system("pause");
    return 0;
}

感谢。

Answer 1

您需要将MySQL连接器库链接到可执行文件。在此之前，您需要决定选择哪种链接。 MySQL连接器支持两种不同的链接：静态或动态。

在official website上有一个教程，展示了如何在Netbeans中创建一个具有链接类型的简单项目。我不知道你是否使用Netbeans，但我很确定你能够在任何其他IDE上复制所描述的操作。

最后，请确保已正确安装MySQL连接器。请查看official documentation以了解如何为您的操作系统执行此操作。

mysql c ++连接器链接错误

1 个答案: