描述

java.sql.Connection是JDBC规范中代表Java程序与数据库之间物理连接的核心接口，用于建立JDBC客户端到数据库的连接，也是所有数据库操作的“基础入口”。无论是执行SQL语句、调用存储过程，还是管理事务，都必须先通过Connection建立与数据库的连接，通过DriverManager.getConnection(url, user, password) 方法获取。

详细接口说明请参考JDBC官方网站 (opens new window)。

方法

YashanDB JDBC驱动对connection接口有如下方法（单机部署/共享集群/分布式集群部署）：

方法	返回类型	备注
createStatement()	Statement	-
createClob()	Clob	-
createBlob()	Blob	-
createStatement(int resultSetType, int resultSetConcurrency)	Statement	-
createStatement(int resultSetType, int resultSetConcurrency, int resultSetHoldability)	Statement	-
prepareStatement(String sql, int resultSetType, int resultSetConcurrency, int resultSetHoldability)	PreparedStatement	-
prepareStatement(String sql)	PreparedStatement	-
prepareStatement(String sql, int resultSetType,int resultSetConcurrency)	PreparedStatement	-
prepareStatement(String sql, int autoGeneratedKeys)	PreparedStatement	-
PreparedStatement prepareStatement(String sql, int columnIndexes[])	PreparedStatement	-
PreparedStatement prepareStatement(String sql, String columnNames[])	PreparedStatement	-
prepareCall(String sql)	CallableStatement	-
setAutoCommit(boolean autoCommit)	void	-
getAutoCommit()	boolean	-
commit()	void	-
rollback()	void	-
close()	void	-
isClosed()	boolean	-
getMetaData()	DatabaseMetaData	-
isReadOnly()	boolean	-
setTransactionIsolation(int level)	void	支持以下三个值： Connection.TRANSACTION_READ_COMMITTED = 2 Connection.TRANSACTION_SERIALIZABLE = 8 YasConnection.TRANSACTION_READ_CURRENT_COMMITTED = 3
getTransactionIsolation()	int	-
getTypeMap()	java.util.Map<String,Class<?>>	-
setTypeMap(java.util.Map<String,Class<?>> map)	void	-
getHoldability()	int	-
setSavepoint()	Savepoint	-
setSavepoint(String name)	Savepoint	-
Struct	createStruct(String typeName, Object[] attributes)	-
rollback(Savepoint savepoint)	void	-
isValid(int timeout)	boolean	-
setSchema(String schema)	void	-
getSchema()	String	-
abort(Executor executor)	void	-
setNetworkTimeout(Executor executor, int milliseconds)	void	-
getNetworkTimeout()	int	-
prepareCall(String sql, int resultSetType, int resultSetConcurrency)	CallableStatement	-
prepareCall(String sql, int resultSetType, int resultSetConcurrency,int resultSetHoldability)	CallableStatement	-
createSQLXML()	SQLXML	-
releaseSavepoint(Savepoint savepoint)	void	-

YashanDB JDBC驱动对connection接口有如下方法（存算一体分布式集群部署）：

方法	返回类型	备注
createStatement()	Statement	-
createStatement(int resultSetType, int resultSetConcurrency)	Statement	-
createStatement(int resultSetType, int resultSetConcurrency, int resultSetHoldability)	Statement	-
prepareStatement(String sql, int resultSetType, int resultSetConcurrency, int resultSetHoldability)	PreparedStatement	-
prepareCall(String sql)	CallableStatement	-
prepareCall(String sql, int resultSetType, int resultSetConcurrency)	CallableStatement	-
prepareCall(String sql, int resultSetType, int resultSetConcurrency,int resultSetHoldability)	CallableStatement	-
prepareStatement(String sql, int resultSetType,int resultSetConcurrency)	PreparedStatement	-
prepareStatement(String sql)	PreparedStatement	-
setAutoCommit(boolean autoCommit)	void	-
getAutoCommit()	boolean	-
commit()	void	-
rollback()	void	-
close()	void	-
isClosed()	boolean	-
getMetaData()	DatabaseMetaData	-
isReadOnly()	boolean	-
getTypeMap()	java.util.Map<String,Class<?>>	-
setTypeMap(java.util.Map<String,Class<?>> map)	void	-
getHoldability()	int	-
isValid(int timeout)	boolean	-
setSchema(String schema)	void	-
getSchema()	String	-
abort(Executor executor)	void	-
setNetworkTimeout(Executor executor, int milliseconds)	void	-
getNetworkTimeout()	int	-
createClob()	Clob	-
createBlob()	Blob	-
setSavepoint()	Savepoint	-
setSavepoint(String name)	Savepoint	-
Struct	createStruct(String typeName, Object[] attributes)	-
rollback(Savepoint savepoint)	void	-
createSQLXML()	SQLXML	-
setHoldability(int holdability)	void	-
setTransactionIsolation(int level)	void	只支持一个取值：Connection.TRANSACTION_READ_COMMITTED = 2
getTransactionIsolation()	int	-
releaseSavepoint(Savepoint savepoint)	void	-

YashanDB JDBC驱动YasConnection扩展接口功能：

方法	返回类型	备注
setClientPrepare(boolean clientPrepare)	void	表示对于绑定参数执行场景，是否开启直接执行；默认不开启，JDBC客户端会先向服务端发送prepare命令然后发送绑定参数执行；若开启，则会将prepareStatement的SQL语句和要绑定的参数一次性发给服务端，减少交互次数。 示例： Connection conn = getConnection("sales", "sales"); ((YasConnection)conn).setClientPrepare(true);
getClientPrepare();	boolean	是否开启直接执行。
registerTAFCallback(YasFailover yasFailover, Object ctxt)	void	注册TAF回调函数的实现类，如果注册了回调函数，failoverRetries和failoverDelay参数不生效，TAF链接失败时不会尝试进行重连。详细见TAF相关接口
createArray(String typeName, Object[] elements)	Array	根据Array的Name创建Array对象，用来替代createArrayOf接口
getDefaultFetchSize()	int	-
setDefaultFetchSize(int fetchSize)	void	-
getSessionTimeZoneOffset()	string	获取当前连接的时区偏移量。
setSessionTimeZoneOffset(String timeZone)	void	设置当前连接的时区偏移量。

示例

package quickstart;

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.Savepoint;
import java.sql.SQLException;
import java.util.Properties;

public class ConnectionManager {

    public static Connection getConnection() throws SQLException {
        String url = "jdbc:yasdb://192.168.1.2:1688/yasdb";
        Properties info = new Properties();
        info.setProperty("user", "sales");
        info.setProperty("password", "sales");
        Class.forName("com.yashandb.jdbc.Driver");
        return DriverManager.getConnection(url, info);
    }

    public void completeConnectionDemo() throws SQLException {
        try (Connection conn = getConnection()) {
            // 1. 设置连接属性
            conn.setAutoCommit(false);
            conn.setReadOnly(false);
            conn.setTransactionIsolation(Connection.TRANSACTION_READ_COMMITTED);

            // 2. 获取元数据
            DatabaseMetaData metaData = conn.getMetaData();
            System.out.println("Connected to: " + metaData.getDatabaseProductName());

            // 3. 执行事务
            executeTransaction(conn);

            // 4. 检查连接状态
            if (conn.isValid(10)) {
                System.out.println("Connection is valid");
            }
        }
    }

    private void executeTransaction(Connection conn) throws SQLException {
        Savepoint savepoint = null;
        try {
            // 创建保存点
            savepoint = conn.setSavepoint("BEFORE_OPERATIONS");

            // 执行多个操作
            executeOperations(conn);

            // 提交事务
            conn.commit();
            System.out.println("Transaction committed successfully");

        } catch (SQLException e) {
            if (savepoint != null) {
                // 回滚到保存点
                conn.rollback(savepoint);
                System.out.println("Rolled back to savepoint");
            } else {
                // 完全回滚
                conn.rollback();
                System.out.println("Transaction rolled back");
            }
            throw e;
        }
    }

    private void executeOperations(Connection conn) throws SQLException {
        // 执行特定操作
    }
}