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我試圖連接到我的應用程序中的QMYSQL數據庫,但每次使用此代碼異常「無法打開數據庫」引發。 Mysql服務器正在運行,沒有任何阻塞連接。難道我做錯了什麼?無法連接到QMYSQL數據庫
這是我來自的類。 .H:
class DatabaseConnection
{
public:
DatabaseConnection(){};
virtual ~DatabaseConnection() {};
protected:
void createConnection
(const char* dbtype, const char* connection,
const char* hostname, const char* dbName, const char* username,
const char* password, int port);
void closeDb();
bool isOpen() const;
QSqlDatabase& getDb(const char* connection);
private:
QSqlDatabase db;
};
的.cpp
#include "DatabaseConnection.h"
void DatabaseConnection::createConnection(const char* dbtype, const char* connection,
const char* hostname, const char* username, const char* dbName, const char* password, int port)
{
db = QSqlDatabase::addDatabase(dbtype, connection);
db.setHostName(hostname);
db.setDatabaseName(dbName);
db.setUserName(username);
db.setPassword(password);
db.setPort(port);
}
void DatabaseConnection::closeDb()
{
db.close();
}
bool DatabaseConnection::isOpen() const
{
return db.isOpen();
}
QSqlDatabase& DatabaseConnection::getDb(const char* connection)
{
return db;
}
這就是我如何使用它。 .H:
class AuthorizeUser : private DatabaseConnection
{
public:
explicit AuthorizeUser()
{
createConnection("QMYSQL", "", "", "users", "root", "root", 3306);
};
~AuthorizeUser() { closeDb(); };
....
的.cpp
#include "Authorization.h"
void AuthorizeUser::checkCredentials(const QString& m_login, const QString& m_password)
{
if (!isOpen())
throw "Cannot open DB!";
getUsersQuery.exec("SELECT * FROM users");
....
您應該嘗試分析'QSqlDatabase'中的'lastError' –