My code keep return "TNS:connect descriptor is too long" massage during try connect oracle database
I can't find what is the problem.
using namespace oracle::occi;
int main() {
try {
Environment *env = Environment::createEnvironment();
Connection *conn = env->createConnection(username, password, database);
} catch (SQLException &e) {
std::cerr << "Error connecting to database: " << e.what() << std::endl;
return 1;
}
return 0;
}
I couldn't find any incorrect point from 'tnsnames.ora', '~/.bash_profile', 'etc...' .
And checked to sqlplus, but there was nothing wrong.
sqlplus ID/PW#DBSID
Connected to:
Oracle Database 19c Standard Edition 2 Release 19.0.0.0.0 - Production
Version 19.11.0.0.0
SQL> conn success
What can i do for resolve this problem?
this is my environment
instant client version : 19_18
Client OS : rocky linux9
Oracle DB version : 19_11
DB OS : CentOS 8
Related
I have a problem with a QSqlQuery when I execute a source command on my database.
This code works :
QString myRequest = "CREATE DATABASE MY_DATABASE;";
lQueryResult.Exec(myRequest);
if(!lQueryResult.GetMexec())
{
qDebug() << "Error in the request";
return false;
}
else
{
qDebug() << "The request is OK";
}
This code doesn't works, I have a syntax error :
You have an error in
your SQL syntax; check the manual that corresponds to your MariaDB
server version for the right syntax to use near 'source
./folder/myFile.sql' at line 1 QMYSQL: Unable to execute query
This is the code :
myRequest = "source myFile.sql";
lQueryResult.Exec(myRequest);
if(!lQueryResult.GetMexec())
{
qDebug() << "Error";
qDebug() << lQueryResult.LastError();
return false;
}
else
{
qDebug() << "OK";
}
I can successfully do my source with this command :
QString lCommand("mysql -uUsername -pPassword Data_Base -e \"source " + variablePath + variableFile + ".sql\"");
system(lCommandeProvisoire.toStdString().c_str());
I have no error. But, if I execute this code juste after, I have the error
No database selected QMYSQL: Unable to execute query
:
TheRequest = "SELECT * FROM MyTable;";
QueryResult.Exec(TheRequest);
if(!QueryResult.GetMexec())
{
qDebug() << QueryResult.LastError();
return false;
}
else
{
qDebug() << "OK";
}
But, If I execute a select * from MyTable in shell, it works.
Also, if I execute this in a shell logged in mysql, it works :
source myFile.sql
SOURCE is MySQL client command which means it is executed by MySQL shell, not by MySQL server, so you can't execute it via QSqlQuery. You can work around this by reading whole file and then sending it's contents to server.
I want to package my Qt application with an existing Sqlite db. I have the standard Qt database code:
m_db = QSqlDatabase::addDatabase("QSQLITE");
m_db.setDatabaseName("database.sqlite");
bool connected = m_db.open();
if (!connected) {
qDebug() << "Error: connection with database failed";
} else {
qDebug() << "Database: connection success";
QSqlQuery q(m_db);
q.prepare("SELECT * FROM people");
if (q.exec()) {
qDebug() << "Yay!";
} else {
qWarning() << "Bad exec: " << q.lastError();
qWarning() << q.executedQuery();
}
}
However, the result is:
Error: connection with database failed
I know this is because it's not finding the correct database, and is instead creating a new one. If I provide the absolute path on my development machine to m_db.setDatabaseName(), it works. But my database file is in my .qrc and will not be available in that location when I deploy... so how can I get a reliable path for this database?
in the setDatabaseName-call use the right syntax for resource files:
m_db.setDatabaseName(":database.sqlite"); // <-- note the : before the name
... presuming the database file is located in the root of your resource file system.
Greetings, Thomas
I'm trying to connect to a MS SQL Server on a remote box using QODBC in my Qt Linux application.
Here's what I have done so far:
Added QT += SQL in the .pro file.
Tested some db functions:
QStringList drivers = QSqlDatabase::drivers();
qDebug() << "Drivers: " ;
foreach(QString driver, drivers) {
qDebug() << ":: " << driver;
}
qDebug() << "Connection Names: ";
QStringList connames = QSqlDatabase::connectionNames();
foreach(QString conname, connames) {
qDebug() << ":: " << conname;
}
qDebug() << "---";
these both work, though connectionNames() is empty at this stage.
I have tried to added a database:
QString serverName = "server1";
QString dbName = "abc123";
QSqlDatabase db = QSqlDatabase::addDatabase("QODBC", "MyFirst");
db.setHostName(serverName);
QString myCon = QString("DRIVER={SQL Native Client};SERVER=%1;DATABASE=%2;Trusted_Connection = Yes").arg(serverName).arg(dbName);
db.setDatabaseName(myCon);
If I now list the connections, "MyFirst" is in the list.
Tried to open the database:
bool ok = db.open();
qDebug() << "OK: " << ok;
if (!ok) {
qDebug() << "error: " << db.lastError().text();
}
The db.open() fails with the following message:
"[unixODBC][Driver Manager]Can't open lib 'SQL Native Client' : file not found QODBC3: Unable to connect"
My questions are:
I picked up the connection string from a forum post, I figured it was as good a place to start as any, but what exactly should be in there? Where does "SQL NAtive Client" come from? What do I need to do to setup my Qt / Linux box to be able to connect to a remote MS SQL Server?
Sounds like you need to install the SQL Server ODBC Driver.
An explanation for how to do that is here:
https://technet.microsoft.com/en-us/library/hh568454(v=sql.110).aspx
In addition you need to refer to it by the correct name, which is "ODBC Driver 11 for SQL Server"
I've been trying to use the mysql++ library in my application (windows x64 based) but I can't seem to connect to my sql server.
Some information:
I used this code to connect to the server:
mysqlpp::Connection conn(db, 0, user, pass, 3306);
this definitely has the right data in it.
and then, my sql server is the standard service from the MySQL install. And I'm pretty sure I used the standard settings. I can connect to it using the MySql Workbench and I edited some new tables and such but my own program doesn't seem to connect.
I read the documentation and I can't find anything specific that might suggest something why I can't connect.
Oh, so many issues, so little time...
Have you checked that your program has permissions to access the database?
Does your program have the correct privileges?
Is your host name correct?
What errors are you getting?
What exception is thrown?
When you use the debugger, what line is the error on?
Here's my method:
sql::Connection * const
Manager ::
get_db_connection(void) const
{
//-------------------------------------------------------------------------
// Use only one connection until proven that more connections will make
// the program more efficient or have a beneficial impact on the user.
// Thus the change in returning sql::Connection * rather than a smart pointer.
// A smart pointer will delete its contents.
//-------------------------------------------------------------------------
static const char host_text[] = "tcp://127.0.0.1:3306/";
static std::string host_name;
if (!m_connection_initialized)
{
host_name = host_text;
initialize_db_driver();
host_name += m_dataset_info.m_dsn_name;
try
{
m_p_connection = m_p_sql_driver->connect(host_name.c_str(),
m_dataset_info.m_user_name.c_str(),
m_dataset_info.m_password.c_str());
}
catch (sql::SQLException &e)
{
/*
The MySQL Connector/C++ throws three different exceptions:
- sql::MethodNotImplementedException (derived from sql::SQLException)
- sql::InvalidArgumentException (derived from sql::SQLException)
- sql::SQLException (derived from std::runtime_error)
*/
wxString wx_text = wxT("# ERR: SQLException in ");
wx_text += wxT(__FILE__);
wxLogDebug(wx_text);
wx_text.Printf(wxT("# ERR: (%s) on line %d"),
__FUNCTION__,
__LINE__);
wxLogDebug(wx_text);
wx_text.Printf(wxT("# ERR: %s (MySQL error code: %d, SQLState: %s)"),
e.what(),
e.getErrorCode(),
e.getSQLState());
wxLogDebug(wx_text);
wxLogDebug(wxT("Verify that mysqlcppconn.dll is in the PATH or in the working directory."));
// throw Manager_Connection_Not_Initialized();
m_connection_initialized = false;
}
catch (...)
{
std::cout << "Unhandled database SQL exception\n" << flush;
m_connection_initialized = false;
}
m_connection_initialized = true;
}
return m_p_connection;
}
PROBLEM: What's the cause of the memory leaks?
SITUATION:
I've build a simple command line program using C++ together with MySQL using the MySQL C API
The problem is, the program has many "minor" memory leaks from the object malloc xx bytes" with xx ranging from a few bytes to 8 kb. All of the leaks links to the library libmysqlclient.18.dylib.
I've already removed all the mysql_free_result() from the code to see if that was the problem, but its still the same.
My MySQL code mainly consists of simple code like:
to connect:
MYSQL *databaseConnection()
{
// declarations
MYSQL *connection = mysql_init(NULL);
// connecting to database
if(!mysql_real_connect(connection,SERVER,USER,PASSWORD,DATABASE,0,NULL,0))
{
std::cout << "Connection error: " << mysql_error(connection) << std::endl;
}
return connection;
}
executing a query:
MYSQL_RES *getQuery(MYSQL *connection, std::string query)
{
// send the query to the database
if (mysql_query(connection, query.c_str()))
{
std::cout << "MySQL query error: " << mysql_error(connection);
exit(1);
}
return mysql_store_result(connection);
}
example of a query:
void resetTable(std::string table)
{
MYSQL *connection = databaseConnection();
MYSQL_RES *result;
std::string query = "truncate table " + table;
result = getQuery(connection, query);
mysql_close(connection);
}
First of all: Opening a new connection for every query (like you're doing in resetTable()) is incredibly wasteful. What you really want to do is open a single connection when the application starts, use that for everything (possibly by storing the connection in a global), and close it when you're done.
To answer your question, though: You need to call mysql_free_result() on result sets once you're done with them.