Oracle数据库连接池在C++中的实现

在C++中实现Oracle数据库连接池，可以使用Oracle官方提供的Oracle Call Interface (OCI) 库

1. 首先，确保已经安装了Oracle客户端库和OCI库。可以从Oracle官网下载并安装。

2. 包含必要的头文件：

#include <occi.h> #include<iostream> #include<vector> #include <mutex> #include<condition_variable> 

3. 定义一个连接池类，如下所示：

class OracleConnectionPool { public:     OracleConnectionPool(const std::string& connectionString, const std::string& userName, const std::string& password, int poolSize);     ~OracleConnectionPool();      oracle::occi::Connection* getConnection();     void releaseConnection(oracle::occi::Connection* connection);  private:     std::vector<oracle::occi::Connection*> connections_;     std::vector<bool> connectionStatus_;     std::mutex mutex_;     std::condition_variable cv_; }; 

4. 实现连接池类的构造函数、析构函数、获取连接和释放连接的方法：

OracleConnectionPool::OracleConnectionPool(const std::string& connectionString, const std::string& userName, const std::string& password, int poolSize) {     for (int i = 0; i< poolSize; ++i) {         oracle::occi::Environment* env = oracle::occi::Environment::createEnvironment(oracle::occi::Environment::DEFAULT);         oracle::occi::Connection* conn = env->createConnection(userName, password, connectionString);         connections_.push_back(conn);         connectionStatus_.push_back(true);     } }  OracleConnectionPool::~OracleConnectionPool() {     for (auto conn : connections_) {         conn->close();         oracle::occi::Environment::terminateEnvironment(conn->getEnvironment());     } }  oracle::occi::Connection* OracleConnectionPool::getConnection() {     std::unique_lock<std::mutex> lock(mutex_);     cv_.wait(lock, [this] { return std::any_of(connectionStatus_.begin(), connectionStatus_.end(), [](bool status) { return status; }); });      auto it = std::find(connectionStatus_.begin(), connectionStatus_.end(), true);     size_t index = std::distance(connectionStatus_.begin(), it);     connectionStatus_[index] = false;      return connections_[index]; }  void OracleConnectionPool::releaseConnection(oracle::occi::Connection* connection) {     std::unique_lock<std::mutex> lock(mutex_);     auto it = std::find(connections_.begin(), connections_.end(), connection);     size_t index = std::distance(connections_.begin(), it);     connectionStatus_[index] = true;     cv_.notify_one(); } 

5. 使用连接池：

int main() {     OracleConnectionPool pool("localhost:1521/XE", "username", "password", 5);      oracle::occi::Connection* conn = pool.getConnection();     oracle::occi::Statement* stmt = conn->createStatement("SELECT * FROM your_table");     oracle::occi::ResultSet* rs = stmt->executeQuery();      while (rs->next()) {         // 处理查询结果     }      stmt->closeResultSet(rs);     conn->terminateStatement(stmt);     pool.releaseConnection(conn);      return 0; } 

这样就实现了一个简单的Oracle数据库连接池。请注意，这个实现仅作为示例，实际应用中可能需要根据需求进行调整和优化。