I can't connecte mysql database?

[foxgod]

my version is QT5.2.1 and there is qmysql.dll in plugins\sqldrivers ,mysql version is mysql-5.5.28-winx64 .my os is windows7. but when i connecte database ,there is some eroor----QSqlDatabase: QMYSQL driver not loaded, i don't know why,

there is anthoer question .only one man can connect mysql by qt5.2.1,but he can't update database table by
int USessionId= 100;
query.prepare("UPDATE users SET SessionId = ? WHERE UserId = userID");
query.bindValue(0,USessionId);
query.exec();
QSqlError(2036, "QMYSQL3: Unable to bind value", "Using unsupported buffer type: 3735604 (parameter: 1)")
who can tell where is worng?

[MrMNight]

first question: in program folder you must create directory "sqldrivers" and put there file "qsqlmysql4.dll" (for qt 4.8.x, for qt5 i think something simillar).
In your program folder you have to put files: libmysql.dll, QtSql4.dll (obv for Qt5 i think it would be QtSql5.dll)

[foxgod]

NO ，there is folder int C:\Qt5.2.1\5.2.1\mingw48_32\plugins\sqldrivers

there is also libmysql.dll Qt5Sql.dll in C:\Qt5.2.1\5.2.1\mingw48_32\bin

who can tell me where is worng?

[MrMNight]

Do you trying to build your program or directly run binary file you already builded?