package com.gordon.jdbc;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

public class jdbc01 {

	public static void main(String[] args) {

		// selectFunction();

		// insertFunction();

		// updateFunction();

		// deleteFunction();

	}

	public static void deleteFunction() {

		try {

			Class.forName("com.mysql.jdbc.Driver");

			Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "root", "root");

			String sql = "DELETE FROM user WHERE ID = ?";

			PreparedStatement st = conn.prepareStatement(sql);

			st.setString(1, "4");

			int res = st.executeUpdate();

			if (res > 0) {

				System.out.println("delete success.");

			} else if (res == 0) {

				System.out.println("deleted.");

			} else {

				System.out.println("delete faild.");

			}

			st.close();

			conn.close();

		} catch (Exception e) {

			System.out.println(e.getMessage());

		}

	}

	public static void updateFunction() {

		try {

			Class.forName("com.mysql.jdbc.Driver");

			Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "root", "root");

			String sql = "UPDATE user SET name = ? WHERE ID = ?";

			PreparedStatement st = conn.prepareStatement(sql);

			st.setString(1, "zhangsan");

			st.setString(2, "4");

			int res = st.executeUpdate();

			if (res > 0) {

				System.out.println("update success.");

			} else {

				System.out.println("update faild.");

			}

			st.close();

			conn.close();

		} catch (Exception e) {

			System.out.println(e.getMessage());

		}

	}

	public static void insertFunction() {

		try {

			Class.forName("com.mysql.jdbc.Driver");

			Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "root", "root");

			String sql = "INSERT INTO user (name) VALUES (?)";

			PreparedStatement st = conn.prepareStatement(sql);

			st.setString(1, "name");

			int res = st.executeUpdate();

			if (res > 0) {

				System.out.println("insert success.");

			} else {

				System.out.println("insert faild.");

			}

			st.close();

			conn.close();

		} catch (Exception e) {

			System.out.println(e.getMessage());

		}

	}

	public static void selectFunction() {

		try {

			// 1.设置驱动

			Class.forName("com.mysql.jdbc.Driver");

			// 2.获取连接

			Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "root", "root");

			// 3.sql语句

			String sql = "SELECT * FROM user";

			// 3.获取SQL执行者

			PreparedStatement st = conn.prepareStatement(sql);

			// 4.设置参数

			// 5.执行sql语句

			ResultSet rs = st.executeQuery();

			// 6.处理数据

			while (rs.next()) {

				System.out.println(rs.getString("id") + ":" + rs.getString("name"));

			}

			// 7.释放资源

			rs.close();

			st.close();

			conn.close();

		} catch (Exception e) {

			System.out.println(e.getMessage());

		}

	}

}