orale数据库连接和增删查改

1、数据库的连接类和增删查改1. 使用 preparedstatement 接口的对象来执行对数据库的增加数据操作PreparedStatement ps = conn.prepareStatement("insert into表 A(a,b)values(?,?)");ps.setString(0,"aaaa");ps.setString(1,"bbbb");ps.execute();conn.close();2.DBUtils 类, 是一个单例模式，用来创建数据库连接，执行预处理，和关闭数 据库，里面的方法都是静态的，直接用类名 .

2、方法就可以调用了。import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class DBUtils static try / 加载数据库驱动Class.forName("oracle.jdbc.OracleDriver"); catch (ClassNotFoundExcep

3、tion e) e.printStackTrace();/ 获取数据库连接对象public static Connection getConn() Connection conn = null;try /"jdbc:oracle:thin:localhost:1521:名字", " 用户名"," 密码"conn=DriverManager.getConnection("jdbc:oracle:thin:192.168.161.3 :1521:MYDB", "scott","tiger&

4、quot;); catch (SQLException e) e.printStackTrace();return conn;/ 获取语句执行对象public static Statement getStatement(Connection conn) Statement stmt = null;try stmt = conn.createStatement(); catch (SQLException e) / TODO Auto-generated catch block e.printStackTrace(); return stmt;/ 获取预处理语句执行对象public static

5、 PreparedStatement getPreparedStatement(Connection conn,String sql) PreparedStatement pstmt = null;try pstmt = conn.prepareStatement(sql); catch (SQLException e) e.printStackTrace();return pstmt;/ 获取结果集对象public static ResultSet getResultSet(PreparedStatement pstmt) ResultSet res = null;try res = pst

6、mt.executeQuery(); catch (SQLException e) e.printStackTrace();return res;/ 获取结果集对象public static ResultSet getResultSet(Statement stmt, String sql) ResultSet res = null;try res = stmt.executeQuery(sql); catch (SQLException e) e.printStackTrace();return res;/ 关闭资源方法 public static void close(Connection

7、 conn, Statement stmt, ResultSet res) close(res); close(stmt); close(conn);/ 封装方法关闭语句对象 private static void close(Statement stmt) if (stmt != null) try stmt.close(); catch (SQLException e) / TODO Auto-generated catch block e.printStackTrace(); stmt = null;/ 封装方法关闭结果集对象 private static void close(Resu

8、ltSet res) if (res != null) try res.close(); catch (SQLException e) / TODO Auto-generated catch block e.printStackTrace(); res = null;/ 封装方法关闭数据库连接对象 private static void close(Connection conn) try if (conn != null && !conn.isClosed() conn.close(); catch (SQLException e) / TODO Auto-generated

9、 catch block e.printStackTrace(); conn = null;/Daolmpl类，实现dao层的具体实现，这里只提供插入数据的方法的关键代码。 public boolean add(ABean msg)/ 返回影响的行数int row = 0;/ 建立数据库连接Connection conn = DBUtils.getConn();/要执行的SQL语句String sql = "insert into A(a,b)values(?,?)"/ 用 PreparedStatement 语句执行对象执行 sql 语句PreparedStatement

10、 pstmt = DBUtils.getPreparedStatement(conn, sql);try pstmt.setString(1, msg.getA(); pstmt.setString(2, msg.getB();/ 执行row = pstmt.executeUpdate(); catch (SQLException e) / TODO Auto-generated catch block e.printStackTrace(); finally / 断开连接DBUtils.close(conn, pstmt, null);/ 返回结果System.out.println(&qu

11、ot; 增加了" + row + " 行！"); return (row > 0 ? true : false);import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException;/* 此类专门连接数据库*/public class Jdbc private Connection conn;private static final String DRlVER ="oracle.jdbc.driver.OracleDriver"pr

12、ivate static final String URL = "jdbc:oracle:thin:localhost:1521:ORCL"private static final String USER = "scott"private static final String PASSWORD = "123456"public Jdbc() try / 加载驱动 Class.forName(DRIVER);/ 连接数据库 this.conn = DriverManager.getConnection(URL,USER,PASSWOR

13、D); catch (ClassNotFoundException e) e.printStackTrace(); catch (SQLException e) e.printStackTrace();/ 返回 Connectionpublic Connection getConnection() return this.conn;一下是插入数据的方法调用 public class Operate private Connection conn; private PreparedStatement prst; private String sql; public Operate() Jdbc

14、jdbc = new Jdbc(); this.conn = jdbc.getConnection();public void insert() sql = "insert into A values(a_value,b_value) " try this.prst = this.conn.prepareStatement(sql); this.prst.executeUpdate();catch(Exception ex) ex.printStackTrace();finally this.close();/ 关闭数据库操作(自己写)import java.sql.Con

15、nection;import java.sql.DriverManager;import java.sql.SQLException;/* 此类专门连接数据库*/public class Jdbc private Connection conn;private static final String DRIVER = "oracle.jdbc.driver.OracleDriver"private static final String URL = "jdbc:oracle:thin:localhost:1521:ORCL"private static

16、final String USER = "scott"private static final String PASSWORD = "123456"public Jdbc() try /加载驱动Class.forName(DRIVER);/连接数据库this.conn =DriverManager.getConnection(URL,USER,PASSWORD); catch (ClassNotFoundException e) e.printStackTrace(); catch (SQLException e) e.printStackTrace();/ 返回 Connectionpublic Connection getConnection() return this.conn;一下是插入数据的方法调用public class Operate private Connection conn;private PreparedStatement prst;private String sql;public Operate() Jdbc jdbc = new Jdbc();t