Java学习历程(数据库与JDBC)

import java.sql.Connection;
import java.sql.Statement;
import java.sql.ResultSet;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.PreparedStatement;

public class TestJDBC2 {

public static void main(String[] args) {
test_Transaction();
}

//下面是一个JDBC连接的基本步骤
public static void test_JDBC() {
Connection conn = null;
Statement stmt = null;

try{

Class.forName("oracle.jdbc.driver.OracleDriver");			//向DriverManager注册驱动
conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:oacl","zhangrui","zhangrui"); 		//连接数据库
stmt = conn.createStatement();				//创建对话描述

} catch(ClassNotFoundException ae) {
ae.printStackTrace();
} catch(SQLException ae) {
ae.printStackTrace();
} finally {
try {
if(stmt != null) {
stmt.close();
}
if(conn != null) {
conn.close();
}
} catch(SQLException ae) {
ae.printStackTrace();
}
}

}

public static void test_DML_Batch() {
Connection conn = null;			//用于取得连接
Statement stmt = null;			//用于取得对话描述
ResultSet rs = null;			//用于获取结果

try {
Class.forName("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl","zhangrui","zhangrui");
stmt = conn.createStatement();

rs = stmt.executeQuery("select * from emp");				//取得查询结果
while(rs.next()) {
System.out.println(rs.getString("sal"));				//打印查询结果
}

stmt.addBatch("insert into dept2 values(60,'SC','AAA')");			//将命令添加到批处理
stmt.addBatch("insert into dept2 values(61,'AM','BBB')");
stmt.addBatch("insert into dept2 values(62,'XK','CCC')");
stmt.executeBatch();							//执行批处理

} catch(ClassNotFoundException ae) {
System.out.println("this driver not found!");
} catch(SQLException ae) {
ae.printStackTrace();
} finally {
try {
if(rs != null) {
rs.close();
}
if(stmt != null) {
stmt.close();
}
if(conn != null) {
conn.close();
}
} catch(SQLException ae) {
ae.printStackTrace();
}
}

}

public static void test_Prepare_Batch() {
Connection conn = null;
PreparedStatement psmt = null;

try{
Class.forName("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:orcl","zhangrui","zhangrui");
psmt = conn.prepareStatement("insert into dept2 values (? , ? , ?)");				//准备执行的命令，其中数据由问号替代

psmt.setInt(1, 63);				//设置第一个问号为整数63
psmt.setString(2, "BJ");		//第二个为字符串"BJ"
psmt.setString(3, "DDD");		//第三个为字符串"DDD"
psmt.addBatch();				//添加到批处理

psmt.setInt(1, 64);
psmt.setString(2, "SH");
psmt.setString(3, "EEE");
psmt.addBatch();

psmt.setInt(1, 65);
psmt.setString(2, "TJ");
psmt.setString(3, "FFF");
psmt.addBatch();

psmt.executeBatch();			//执行批处理

} catch(ClassNotFoundException ae) {
ae.printStackTrace();
} catch(SQLException ae) {
ae.printStackTrace();
} finally {
try {
if(psmt != null) {
psmt.close();
}
if(conn != null) {
conn = null;
}
} catch(SQLException ae) {
ae.printStackTrace();
}
}
}

public static void test_Transaction() {
Connection conn = null;
Statement stmt = null;

try {
Class.forName("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl","zhangrui","zhangrui");

conn.setAutoCommit(false);					//取消自动提交,以便创建Transaction

stmt = conn.createStatement();
//stmt.executeUpdate("delete from dept2 where dname = 'Game'");
stmt.executeUpdate("insert into dept2 values (34,'Game','Beijing')");
stmt.executeUpdate("update dept52 set loc = 'SHANGHAI' where dname = 'Game'");
conn.commit();					//执行完所有后提交

} catch(ClassNotFoundException ae) {
ae.printStackTrace();
} catch(SQLException ae) {
try {
conn.rollback();				//若提交过程有任何误差,则进行回滚
conn.setAutoCommit(true);			//恢复为自动提交
ae.printStackTrace();				//打印错误
} catch(SQLException a) {
a.printStackTrace();
}
} finally {
try {
if(stmt != null) {
stmt.close();
}
if(conn != null) {
conn.close();
}
} catch(SQLException ae) {
ae.printStackTrace();
}
}

}

}