JDBC

JDBC简介

 　　

　JDBC的工作原理

　　

　JDBC API

　　

连接数据库

　JDBC驱动

　　

　使用JDBC-ODBC桥方式连接数据库

　　

　　

　使用纯Java方式连接数据库

　　

　　

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

import org.apache.log4j.Logger;

public class Conn {
    private static Logger logger = Logger.getLogger(Conn.class.getName());

    public static void main(String[] args) {
        Connection conn = null;
        // 1.加载驱动
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            logger.error(e);
        }
        // 2.建立连接
        try {
            conn = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/epet", "epetadmin", "0000");
            System.out.println("建立连接成功！");
        } catch (SQLException e) {
            logger.error(e);
        } finally {
            // 3.关闭连接
            try {
                if (conn != null) {
                    conn.close();
                    System.out.println("关闭连接成功!");
                }
            } catch (SQLException e) {
                logger.error(e);
            }
        }
    }
}

Statement和ResultSet

　　

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

import org.apache.log4j.Logger;

public class Insert {
    private static Logger logger = Logger.getLogger(Insert.class.getName());

    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;
        String name = "欧欧";
        int health = 100;
        int love = 60;
        String strain = "酷酷的雪纳瑞";
        // 1.加载驱动
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            logger.error(e);
        }
        // 2.建立连接
        try {
            conn = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/epet", "epetadmin", "0000");
            stmt = conn.createStatement();
            // insert into dog(name,health,love,strain)
            // value('欧欧',100,60,'酷酷的雪纳瑞');
            StringBuffer sql = new StringBuffer(
                    "insert into dog(name,health,love,strain) value('");
            sql.append(name + "',");
            sql.append(health + ",");
            sql.append(love + ",'");
            sql.append(strain + "')");
            stmt.execute(sql.toString());
            logger.info("插入狗狗信息成功！");
        } catch (SQLException e) {
            logger.error(e);
        } finally {
            // 3.关闭连接
            try {
                if (stmt != null) {
                    stmt.close();
                }
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e) {
                logger.error(e);
            }
        }
    }
}

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

import org.apache.log4j.Logger;

public class Update {
    private static Logger logger = Logger.getLogger(Update.class.getName());

    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;
        // 1.加载驱动
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            logger.error(e);
        }
        // 2.建立连接
        try {
            conn = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/epet", "epetadmin", "0000");
            stmt = conn.createStatement();
            stmt.executeUpdate("update dog set health=80,love=15 where id=1");
            logger.info("成功更新了狗狗信息！");
        } catch (SQLException e) {
            logger.error(e);
        } finally {
            // 3.关闭连接
            try {
                if (stmt != null) {
                    stmt.close();
                }
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e) {
                logger.error(e);
            }
        }
    }
}

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

import org.apache.log4j.Logger;

public class Query {
    private static Logger logger = Logger.getLogger(Query.class.getName());

    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;
        // 1.加载驱动
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            logger.error(e);
        }
        // 2.建立连接
        try {
            conn = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/epet", "epetadmin", "0000");
            stmt = conn.createStatement();
            rs = stmt
                    .executeQuery("select id,name,health,love,strain from dog");
            while (rs.next()) {
                System.out.println(rs.getInt(1));
                System.out.println(rs.getString(2));
                System.out.println(rs.getInt("health"));
                System.out.println(rs.getInt("love"));
                System.out.println(rs.getString("strain"));
            }
            logger.info("查询狗狗信息成功！");
        } catch (SQLException e) {
            logger.error(e);
        } finally {
            // 3.关闭连接
            try {
                if (rs != null) {
                    rs.close();
                }
                if (stmt != null) {
                    stmt.close();
                }
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e) {
                logger.error(e);
            }
        }
    }
}

PreparedStatement接口

　　

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

import org.apache.log4j.Logger;

public class Update2 {
    private static Logger logger = Logger.getLogger(Update2.class.getName());

    public static void main(String[] args) {
        Connection conn = null;
        PreparedStatement pstmt = null;
        // 1.加载驱动
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            logger.error(e);
        }
        // 2.建立连接
        try {
            conn = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/epet", "epetadmin", "0000");
            String sql = "update dog set health=?,love=? where id=?";
            pstmt = conn.prepareStatement(sql);
            pstmt.setInt(1, 80);
            pstmt.setInt(2, 15);
            pstmt.setInt(3, 1);
            pstmt.executeUpdate();
            logger.info("成功更新了狗狗信息！");
        } catch (SQLException e) {
            logger.error(e);
        } finally {
            // 3.关闭连接
            try {
                if (pstmt != null) {
                    pstmt.close();
                }
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e) {
                logger.error(e);
            }
        }
    }
}