std::vector<Device *> ControllerDatabaseFactory::fetchDevices(
const std::size_t id ) const {
std::vector<Device *> devices;
DatabaseStatement * statement;
DatabaseResult * result;
DatabaseResultRow * row;
std::string query;
std::size_t deviceId;
query =
"SELECT id "
"FROM devices "
"WHERE controller_id = ";
query = query + std::to_string(id);
statement = getDbConnection()->createStatement(query);
if( statement != nullptr ) {
result = statement->execute();
if( result != nullptr ) {
while( result->hasNext() ) {
row = result->next();
deviceId = static_cast<std::size_t>(
atol(row->getColumn(0).c_str()));
devices.push_back(mDeviceContainer->get(deviceId));
delete row;
}
delete result;
}
delete statement;
}
return ( devices );
}
//-----------------------------------------------------------------------------
// 描述: 执行SQL (若 resultDataSet 为 NULL，则表示无数据集返回。若失败则抛出异常)
//-----------------------------------------------------------------------------
void MySqlQuery::doExecute(DbDataSet *resultDataSet)
{
/*
摘自MYSQL官方手册:
Upon connection, mysql_real_connect() sets the reconnect flag (part of the
MYSQL structure) to a value of 1 in versions of the API older than 5.0.3,
or 0 in newer versions. A value of 1 for this flag indicates that if a
statement cannot be performed because of a lost connection, to try reconnecting
to the server before giving up. You can use the MYSQL_OPT_RECONNECT option
to mysql_options() to control reconnection behavior.
即：只要用 mysql_real_connect() 连接到数据库(而不是 mysql_connect())，那么
在 mysql_real_query() 调用时即使连接丢失(比如TCP连接断开)，该调用也会尝试
去重新连接数据库。该特性经测试被证明属实。
注:
1. 对于 <= 5.0.3 的版本，MySQL默认会重连；此后的版本需调用 mysql_options()
明确指定 MYSQL_OPT_RECONNECT 为 true，才会重连。
2. 为了在连接丢失并重连后，能执行“数据库刚建立连接时要执行的命令”，程序明确
指定不让 mysql_real_query() 自动重连，而是由程序显式重连。
*/
for (int times = 0; times < 2; times++)
{
int r = mysql_real_query(&getConnObject(), sql_.c_str(), (int)sql_.length());
// 如果执行SQL失败
if (r != 0)
{
// 如果是首次，并且错误类型为连接丢失，则重试连接
if (times == 0)
{
int errNum = mysql_errno(&getConnObject());
if (errNum == CR_SERVER_GONE_ERROR || errNum == CR_SERVER_LOST)
{
logger().writeStr(SEM_MYSQL_LOST_CONNNECTION);
// 强制重新连接
getDbConnection()->activateConnection(true);
continue;
}
}
// 否则抛出异常
string sql(sql_);
if (sql.length() > 1024*2)
{
sql.resize(100);
sql += "...";
}
string errMsg = formatString("%s; Error: %s", sql.c_str(), mysql_error(&getConnObject()));
iseThrowDbException(errMsg.c_str());
}
else break;
}
}
std::vector<ValueType *> ValueTypeDatabaseFactory::fetchAll( void ) {
DatabaseStatement * statement;
DatabaseResult * result;
DatabaseResultRow * row;
std::vector<ValueType *> types;
std::string strId;
long bufferId;
std::size_t id;
std::string identifier;
std::string name;
std::string description;
std::string regex;
statement = getDbConnection()->createStatement(
"SELECT *"
"FROM value_types"
);
if( statement != nullptr ) {
result = statement->execute();
if( result != nullptr ) {
while( result->hasNext() ) {
row = result->next();
strId = row->getColumn(0);
identifier = row->getColumn(1);
regex = row->getColumn(2);
name = row->getColumn(3);
description = row->getColumn(4);
bufferId = atol(strId.c_str());
id = static_cast<std::size_t>(bufferId);
types.push_back(
new ValueType(id,identifier,name,description,regex)
);
delete row;
}
delete result;
}
delete statement;
}
return ( types );
}
std::vector<Controller *> ControllerDatabaseFactory::fetchAll( void ) {
std::vector<Controller *> controllers;
Controller * controller;
DatabaseStatement * statement;
DatabaseResult * result;
DatabaseResultRow * row;
std::string id;
std::string identifier;
std::string description;
std::string name;
std::string securityCode;
statement = getDbConnection()->createStatement(
"SELECT * "
"FROM controllers;"
);
if( statement != nullptr ) {
result = statement->execute();
if( result != nullptr ) {
while( result->hasNext() ) {
row = result->next();
id = row->getColumn(0);
identifier = row->getColumn(1);
securityCode = row->getColumn(2);
name = row->getColumn(3);
description = row->getColumn(4);
controller = allocateController(id,identifier,name,
description,securityCode);
controllers.push_back(controller);
delete row;
}
delete result;
}
delete statement;
}
return ( controllers );
}