1 import java.sql.Connection; 2 import java.sql.DriverManager; 3 import java.sql.PreparedStatement; 4 import java.sql.SQLException; 5 6 public class LinkDatabseInsert{ 7 public static void main(String[] args) throws ClassNotFoundException, SQLException { 8 //1.註冊數據庫的驅動 9 Class.forName("com.mysql.jdbc.Driver"); 10 //2.獲取數據庫鏈接(裏面內容依次是:"jdbc:mysql://主機名:端口號/數據庫名","用戶名","登陸密碼") 11 Connection connection = DriverManager.getConnection("jdbc:mysql://rm-uf6lgkv4fd9776rxego.mysql.rds.aliyuncs.com:3306/study","root","whmilyY123!"); 12 //3.須要執行的sql語句(?是佔位符,表明一個參數) 13 String sql = "insert into stu(id,name,age) values(?,?,?)"; 14 //4.獲取預處理對象,並依次給參數賦值 15 PreparedStatement statement = connection.prepareCall(sql); 16 statement.setInt(1,10); //數據庫字段類型是int,就是setInt;1表明第一個參數 17 statement.setString(2,"小明"); //數據庫字段類型是String,就是setString;2表明第二個參數 18 statement.setInt(3,16); //數據庫字段類型是int,就是setInt;3表明第三個參數 19 //5.執行sql語句(執行了幾條記錄,就返回幾) 20 int i = statement.executeUpdate(); 21 System.out.println(i); 22 //6.關閉jdbc鏈接 23 statement.close(); 24 connection.close(); 25 } 26 }
1 import java.sql.Connection; 2 import java.sql.DriverManager; 3 import java.sql.PreparedStatement; 4 import java.sql.SQLException; 5 6 public class LinkDatabaseUpdate { 7 public static void main(String[] args) throws ClassNotFoundException, SQLException { 8 //1.註冊數據庫的驅動 9 Class.forName("com.mysql.jdbc.Driver"); 10 //2.獲取數據庫鏈接(裏面內容依次是:"jdbc:mysql://主機名:端口號/數據庫名","用戶名","登陸密碼") 11 Connection connection = DriverManager.getConnection("jdbc:mysql://rm-uf6lgkv4fd9776rxego.mysql.rds.aliyuncs.com:3306/study","root","whmilyY123!"); 12 //3.須要執行的sql語句(?是佔位符,表明一個參數) 13 String sql = "update stu set name=?,age=? where id=?"; 14 //4.獲取預處理對象,並依次給參數賦值 15 PreparedStatement statement = connection.prepareCall(sql); 16 statement.setString(1,"小黃"); //數據庫字段類型是String,就是setString;1表明第一個參數 17 statement.setInt(2,28); //數據庫字段類型是int,就是setInt;2表明第二個參數 18 statement.setInt(3,10); //數據庫字段類型是int,就是setInt;3表明第三個參數 19 //5.執行sql語句(執行了幾條記錄,就返回幾) 20 int i = statement.executeUpdate(); 21 System.out.println(i); 22 //6.關閉jdbc鏈接 23 statement.close(); 24 connection.close(); 25 } 26 }
1 import java.sql.Connection; 2 import java.sql.DriverManager; 3 import java.sql.PreparedStatement; 4 import java.sql.SQLException; 5 6 public class LinkDatabaseDelete { 7 public static void main(String[] args) throws ClassNotFoundException, SQLException { 8 //1.註冊數據庫的驅動 9 Class.forName("com.mysql.jdbc.Driver"); 10 //2.獲取數據庫鏈接(裏面內容依次是:"jdbc:mysql://主機名:端口號/數據庫名","用戶名","登陸密碼") 11 Connection connection = DriverManager.getConnection("jdbc:mysql://rm-uf6lgkv4fd9776rxego.mysql.rds.aliyuncs.com:3306/study","root","whmilyY123!"); 12 //3.須要執行的sql語句(?是佔位符,表明一個參數) 13 String sql = "delete from stu where id=?"; 14 //4.獲取預處理對象,並依次給參數賦值 15 PreparedStatement statement = connection.prepareCall(sql); 16 statement.setInt(1,9); //字段類型是int,就是setInt;1表明第一個參數 17 //5.執行sql語句(執行了幾條記錄,就返回幾) 18 int i = statement.executeUpdate(); 19 System.out.println(i); 20 //6.關閉jdbc鏈接 21 statement.close(); 22 connection.close(); 23 } 24 }
1 import java.sql.*; 2 3 public class LinkDatabseSelect { 4 public static void main(String[] args) throws ClassNotFoundException, SQLException { 5 //1.註冊數據庫的驅動 6 Class.forName("com.mysql.jdbc.Driver"); 7 //2.獲取數據庫鏈接(裏面內容依次是:"jdbc:mysql://主機名:端口號/數據庫名","用戶名","登陸密碼") 8 Connection connection = DriverManager.getConnection("jdbc:mysql://rm-uf6lgkv4fd9776rxego.mysql.rds.aliyuncs.com:3306/study","root","whmilyY123!"); 9 //3.須要執行的sql語句(?是佔位符,表明一個參數) 10 String sql = "select * from stu where id in(?,?)"; 11 //4.獲取預處理對象,並給參數賦值 12 PreparedStatement statement = connection.prepareStatement(sql); 13 statement.setInt(1,1); //字段類型是int,就是setInt;1表明第一個參數 14 statement.setInt(2,4); //字段類型是int,就是setInt;2表明第一個參數 15 //5.執行sql語句(返回結果集) 16 ResultSet resultSet = statement.executeQuery(); 17 while(resultSet.next()){ //若是有下一條記錄 18 String id = resultSet.getString("id"); //根據列名返回值 19 String name = resultSet.getString("name"); //根據列名返回值 20 int age = resultSet.getInt(3); //根據列的順序返回值 21 String gender = resultSet.getString(4); //根據列的順序返回值 22 System.out.println(id+"\t"+name+"\t"+age+"\t"+gender); 23 } 24 //6.關閉jdbc鏈接 25 resultSet.close(); 26 statement.close(); 27 connection.close(); 28 } 29 }