JDBC-圓姥囂鞘斤嵆箭徨
和中頁幣箭處幣泌採聞喘圓姥囂鞘銭揖嬉蝕才購液囂鞘。
幣箭旗鷹児噐岻念譜崔議桟廠才方象垂園亟。
鹸崙娚薮旗鷹欺JDBCExample.java?園咎塰佩泌和?
園咎參貧議箭徨泌和?
輝低塰佩JDBCExample?恢伏泌和補竃?
幣箭旗鷹児噐岻念譜崔議桟廠才方象垂園亟。
鹸崙娚薮旗鷹欺JDBCExample.java?園咎塰佩泌和?
//STEP 1. Import required packages
import java.sql.*;
public class JDBCExample {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/EMP";
// Database credentials
static final String USER = "username";
static final String PASS = "password";
public static void main(String[] args) {
Connection conn = null;
PreparedStatement stmt = null;
try{
//STEP 2: Register JDBC driver
Class.forName("com.mysql.jdbc.Driver");
//STEP 3: Open a connection
System.out.println("Connecting to database...");
conn = DriverManager.getConnection(DB_URL,USER,PASS);
//STEP 4: Execute a query
System.out.println("Creating statement...");
String sql = "UPDATE Employees set age=? WHERE id=?";
stmt = conn.prepareStatement(sql);
//Bind values into the parameters.
stmt.setInt(1, 35); // This would set age
stmt.setInt(2, 102); // This would set ID
// Let us update age of the record with ID = 102;
int rows = stmt.executeUpdate();
System.out.println("Rows impacted : " + rows );
// Let us select all the records and display them.
sql = "SELECT id, first, last, age FROM Employees";
ResultSet rs = stmt.executeQuery(sql);
//STEP 5: Extract data from result set
while(rs.next()){
//Retrieve by column name
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last");
//Display values
System.out.print("ID: " + id);
System.out.print(", Age: " + age);
System.out.print(", First: " + first);
System.out.println(", Last: " + last);
}
//STEP 6: Clean-up environment
rs.close();
stmt.close();
conn.close();
}catch(SQLException se){
//Handle errors for JDBC
se.printStackTrace();
}catch(Exception e){
//Handle errors for Class.forName
e.printStackTrace();
}finally{
//finally block used to close resources
try{
if(stmt!=null)
stmt.close();
}catch(SQLException se2){
}// nothing we can do
try{
if(conn!=null)
conn.close();
}catch(SQLException se){
se.printStackTrace();
}//end finally try
}//end try
System.out.println("Goodbye!");
}//end main
}//end JDBCExample
園咎參貧議箭徨泌和?
C:>javac JDBCExample.java C:>
輝低塰佩JDBCExample?恢伏泌和補竃?
C:>java JDBCExample Connecting to database... Creating statement... Rows impacted : 1 ID: 100, Age: 18, First: Zara, Last: Ali ID: 101, Age: 25, First: Mahnaz, Last: Fatma ID: 102, Age: 35, First: Zaid, Last: Khan ID: 103, Age: 30, First: Sumit, Last: Mittal Goodbye! C:>