我开始学习mysql c ++连接器。 我正在尝试通过互联网提供的示例代码。 但它随机崩溃。 它在发布模式下工作正常。但是当我使用调试模式时它会崩溃。 我是否需要为调试模式提供（添加）任何特定的链接选项？
/* Standard C++ headers */
#include <iostream>
#include <sstream>
#include <memory>
#include <string>
#include <stdexcept>
/* MySQL Connector/C++ specific headers */
#include <driver.h>
#include <connection.h>
#include <statement.h>
#include <prepared_statement.h>
#include <resultset.h>
#include <metadata.h>
#include <resultset_metadata.h>
#include <exception.h>
#include <warning.h>
#define DBHOST "tcp://127.0.0.1:3306"
#define USER "vivek"
#define PASSWORD "vivek"
#define DATABASE "user2"
#define NUMOFFSET 100
#define COLNAME 200
using namespace std;
using namespace sql;
static void retrieve_data_and_print (ResultSet *rs, int type, int colidx, string colname) {
/* retrieve the row count in the result set */
cout << "\nRetrieved " << rs -> rowsCount() << " row(s)." << endl;
cout << "\nCityName" << endl;
cout << "--------" << endl;
/* fetch the data : retrieve all the rows in the result set */
while (rs->next()) {
if (type == NUMOFFSET) {
cout << rs -> getString(colidx) << endl;
} else if (type == COLNAME) {
cout << rs -> getString(colname) << endl;
} // if-else
} // while
cout << endl;
} // retrieve_data_and_print()
static void retrieve_dbmetadata_and_print (Connection *dbcon) {
if (dbcon -> isClosed()) {
throw runtime_error("DatabaseMetaData FAILURE - database connection closed");
}
cout << "\nDatabase Metadata" << endl;
cout << "-----------------" << endl;
cout << boolalpha;
/* The following commented statement won't work with Connector/C++ 1.0.5 and later */
//auto_ptr < DatabaseMetaData > dbcon_meta (dbcon -> getMetaData());
DatabaseMetaData *dbcon_meta = dbcon -> getMetaData();
cout << "Database Product Name: " << dbcon_meta -> getDatabaseProductName() << endl;
cout << "Database Product Version: " << dbcon_meta -> getDatabaseProductVersion() << endl;
cout << "Database User Name: " << dbcon_meta -> getUserName() << endl << endl;
cout << "Driver name: " << dbcon_meta -> getDriverName() << endl;
cout << "Driver version: " << dbcon_meta -> getDriverVersion() << endl << endl;
cout << "Database in Read-Only Mode?: " << dbcon_meta -> isReadOnly() << endl;
cout << "Supports Transactions?: " << dbcon_meta -> supportsTransactions() << endl;
cout << "Supports DML Transactions only?: " << dbcon_meta -> supportsDataManipulationTransactionsOnly() << endl;
cout << "Supports Batch Updates?: " << dbcon_meta -> supportsBatchUpdates() << endl;
cout << "Supports Outer Joins?: " << dbcon_meta -> supportsOuterJoins() << endl;
cout << "Supports Multiple Transactions?: " << dbcon_meta -> supportsMultipleTransactions() << endl;
cout << "Supports Named Parameters?: " << dbcon_meta -> supportsNamedParameters() << endl;
cout << "Supports Statement Pooling?: " << dbcon_meta -> supportsStatementPooling() << endl;
cout << "Supports Stored Procedures?: " << dbcon_meta -> supportsStoredProcedures() << endl;
cout << "Supports Union?: " << dbcon_meta -> supportsUnion() << endl << endl;
cout << "Maximum Connections: " << dbcon_meta -> getMaxConnections() << endl;
cout << "Maximum Columns per Table: " << dbcon_meta -> getMaxColumnsInTable() << endl;
cout << "Maximum Columns per Index: " << dbcon_meta -> getMaxColumnsInIndex() << endl;
cout << "Maximum Row Size per Table: " << dbcon_meta -> getMaxRowSize() << " bytes" << endl;
cout << "\nDatabase schemas: " << endl;
auto_ptr < ResultSet > rs ( dbcon_meta -> getSchemas());
cout << "\nTotal number of schemas = " << rs -> rowsCount() << endl;
cout << endl;
int row = 1;
while (rs -> next()) {
cout << "\t" << row << ". " << rs -> getString("TABLE_SCHEM") << endl;
++row;
} // while
cout << endl << endl;
} // retrieve_dbmetadata_and_print()
static void retrieve_rsmetadata_and_print (ResultSet *rs) {
if (rs -> rowsCount() == 0) {
throw runtime_error("ResultSetMetaData FAILURE - no records in the result set");
}
cout << "ResultSet Metadata" << endl;
cout << "------------------" << endl;
/* The following commented statement won't work with Connector/C++ 1.0.5 and later */
//auto_ptr < ResultSetMetaData > res_meta ( rs -> getMetaData() );
ResultSetMetaData *res_meta = rs -> getMetaData();
int numcols = res_meta -> getColumnCount();
cout << "\nNumber of columns in the result set = " << numcols << endl << endl;
cout.width(20);
cout << "Column Name/Label";
cout.width(20);
cout << "Column Type";
cout.width(20);
cout << "Column Size" << endl;
for (int i = 0; i < numcols; ++i) {
cout.width(20);
cout << res_meta -> getColumnLabel (i+1);
cout.width(20);
cout << res_meta -> getColumnTypeName (i+1);
cout.width(20);
cout << res_meta -> getColumnDisplaySize (i+1) << endl << endl;
}
cout << "\nColumn \"" << res_meta -> getColumnLabel(1);
cout << "\" belongs to the Table: \"" << res_meta -> getTableName(1);
cout << "\" which belongs to the Schema: \"" << res_meta -> getSchemaName(1) << "\"" << endl << endl;
} // retrieve_rsmetadata_and_print()
int main(int argc, const char *argv[]) {
Driver *driver;
Connection *con;
Statement *stmt;
ResultSet *res;
PreparedStatement *prep_stmt;
Savepoint *savept;
int updatecount = 0;
/* initiate url, user, password and database variables */
string url(argc >= 2 ? argv[1] : DBHOST);
const string user(argc >= 3 ? argv[2] : USER);
const string password(argc >= 4 ? argv[3] : PASSWORD);
const string database(argc >= 5 ? argv[4] : DATABASE);
try {
driver = get_driver_instance();
/* create a database connection using the Driver */
con = driver -> connect(url, user, password);
/* alternate syntax using auto_ptr to create the db connection */
//auto_ptr con (driver -> connect(url, user, password));
/* turn off the autocommit */
con -> setAutoCommit(0);
cout << "\nDatabase connection\'s autocommit mode = " << con -> getAutoCommit() << endl;
/* select appropriate database schema */
con -> setSchema(database);
/* retrieve and display the database metadata */
retrieve_dbmetadata_and_print (con);
/* create a statement object */
stmt = con -> createStatement();
cout << "Executing the Query: \"SELECT * FROM City\" .." << endl;
/* run a query which returns exactly one result set */
res = stmt -> executeQuery ("show datbases");
cout << "Retrieving the result set .." << endl;
/* retrieve the data from the result set and display on stdout */
//retrieve_data_and_print (res, NUMOFFSET, 1, string("CityName"));
con -> commit();
/* Clean up */
delete res;
delete stmt;
delete prep_stmt;
con -> close();
delete con;
} catch (SQLException &e) {
cout << "ERROR: SQLException in " << __FILE__;
cout << " (" << __func__<< ") on line " << __LINE__ << endl;
cout << "ERROR: " << e.what();
cout << " (MySQL error code: " << e.getErrorCode();
cout << ", SQLState: " << e.getSQLState() << ")" << endl;
if (e.getErrorCode() == 1047) {
/*
Error: 1047 SQLSTATE: 08S01 (ER_UNKNOWN_COM_ERROR)
Message: Unknown command
*/
cout << "\nYour server does not seem to support Prepared Statements at all. ";
cout << "Perhaps MYSQL < 4.1?" << endl;
}
return EXIT_FAILURE;
} catch (std::runtime_error &e) {
cout << "ERROR: runtime_error in " << __FILE__;
cout << " (" << __func__ << ") on line " << __LINE__ << endl;
cout << "ERROR: " << e.what() << endl;
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
} // main()
答案 0 :(得分：0)
我发现很可能是错误。该库正在为您创建内容，您正在删除它们。 这可能是使用不同的堆管理器，因此会导致问题。
如果这样做，那么API非常差。它应该为您提供删除。是吗？
我在their site找到了类似的东西并告诉他们我的想法：
答案 1 :(得分：0)
这是因为连接器使用的C ++运行时库版本与应用程序不同。连接器创建的对象初始化的方式与应用程序库的方式不同。然后，当你摧毁这个物体时，你会错误地摧毁它。您需要下载连接器的源代码并自行编译。
要下载源代码，请转到http://www.mysql.com/downloads/connector/cpp/#downloads并为平台类型选择“源代码”。
答案 2 :(得分：0)
在调试模式下，为库而不是opt选择调试文件夹。