Witam, od kilku dni szukam sposobu na wstawienie zmiennych w zapytaniu mysql.
korzystam z Visual C++ 2010.
Oto mój prosty program łączący się z Bazą Danych, wszystko działa dane są pobieranie z bazy i wyświetlane, lecz problem pojawia się gdy do zapytania próbuje dodać zmienną...
Chodzi mi oto:
int x = 1;
query_state = mysql_query(&mysql, SELECT * FROM nns_user WHERE user_id = "+ x);
ale wyskakuje mi wtedy błąd:
error C2664: 'mysql_query' : cannot convert parameter 2 from 'System::String ^' to 'const char *'
dlatego użyłem innego sposobu przedstawionego niżej ale również nie działa...
Szukałem, sprawdzałem wszystkiego nie mam pojęcia w czym tkwi problem.
Z góry dziękuje za pomoc ;-)
program wygląda tak:
#pragma once
#include <iostream>
#include <winsock.h>
#include <mysql/mysql.h>
#include <stdio.h>
#include <string.h>
MYSQL *connection, mysql;
MYSQL_RES *result;
MYSQL_ROW row;
int query_state;
namespace MySQLProgram {
using namespace System;
using namespace System::ComponentModel;
using namespace System::Collections;
using namespace System::Windows::Forms;
using namespace System::Data;
using namespace System::Drawing;
/// <summary>
/// Summary for Form1
/// </summary>
public ref class Form1 : public System::Windows::Forms::Form
{
public:
Form1(void)
{
InitializeComponent();
//
//TODO: Add the constructor code here
//
}
protected:
/// <summary>
/// Clean up any resources being used.
/// </summary>
~Form1()
{
if (components)
{
delete components;
}
}
private: System::Windows::Forms::TextBox^ TextBox;
protected:
private: System::Windows::Forms::Button^ Aktualizuj;
private: System::Windows::Forms::TextBox^ TextBox1;
private: System::Windows::Forms::Label^ label1;
private:
/// <summary>
/// Required designer variable.
/// </summary>
System::ComponentModel::Container ^components;
#pragma region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
void InitializeComponent(void)
{
this->TextBox = (gcnew System::Windows::Forms::TextBox());
this->Aktualizuj = (gcnew System::Windows::Forms::Button());
this->TextBox1 = (gcnew System::Windows::Forms::TextBox());
this->label1 = (gcnew System::Windows::Forms::Label());
this->SuspendLayout();
//
// TextBox
//
this->TextBox->Location = System::Drawing::Point(92, 60);
this->TextBox->Multiline = true;
this->TextBox->Name = L"TextBox";
this->TextBox->Size = System::Drawing::Size(360, 133);
this->TextBox->TabIndex = 0;
//
// Aktualizuj
//
this->Aktualizuj->Location = System::Drawing::Point(195, 209);
this->Aktualizuj->Name = L"Aktualizuj";
this->Aktualizuj->Size = System::Drawing::Size(161, 32);
this->Aktualizuj->TabIndex = 1;
this->Aktualizuj->Text = L"Aktualizuj";
this->Aktualizuj->UseVisualStyleBackColor = true;
this->Aktualizuj->Click += gcnew System::EventHandler(this, &Form1::Aktualizuj_Click);
//
// TextBox1
//
this->TextBox1->Location = System::Drawing::Point(234, 12);
this->TextBox1->Name = L"TextBox1";
this->TextBox1->Size = System::Drawing::Size(48, 20);
this->TextBox1->TabIndex = 2;
this->TextBox1->Text = L"1";
//
// label1
//
this->label1->AutoSize = true;
this->label1->Location = System::Drawing::Point(192, 15);
this->label1->Name = L"label1";
this->label1->Size = System::Drawing::Size(18, 13);
this->label1->TabIndex = 3;
this->label1->Text = L"ID";
//
// Form1
//
this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
this->ClientSize = System::Drawing::Size(542, 280);
this->Controls->Add(this->label1);
this->Controls->Add(this->TextBox1);
this->Controls->Add(this->Aktualizuj);
this->Controls->Add(this->TextBox);
this->Name = L"Form1";
this->Text = L"Program";
this->Load += gcnew System::EventHandler(this, &Form1::Form1_Load);
this->ResumeLayout(false);
this->PerformLayout();
}
#pragma endregion
private: System::Void Form1_Load(System::Object^ sender, System::EventArgs^ e)
{
mysql_init(&mysql);
connection = mysql_real_connect(&mysql,"127.0.0.1","root","","datex",0,0,0);
if(connection == NULL)
{
this->TextBox->Text = L"Error: " + gcnew String(mysql_error(&mysql));
this->Aktualizuj->Enabled = false;
}
}
private: System::Void Aktualizuj_Click(System::Object^ sender, System::EventArgs^ e)
{
char sQuery[256];
const char x= 1;
sprintf_s(sQuery, "SELECT * FROM nns_user WHERE user_id = '%s'", x);
query_state = mysql_query(&mysql, sQuery);
result = mysql_store_result(connection);
while ( ( row = mysql_fetch_row(result)) != NULL )
{
this->TextBox->Text = this->TextBox->Text + L"\r\n Imie: " + gcnew String(row[1]) + L" e-mail: " + gcnew String(row[9]);
}
}
};
}