java中嵌入sql语句_java嵌入sql

很多数据库的初学者学了不少sql语句，却知道在程序里怎么执行他们，这里以java为例，介绍一下java的嵌入sql语句

1.简单的链接数据库：

import java.sql.Connection;

import oracle.jdbc.pool.OracleDataSource;

public class TestConnection2 {

 public static void main(String[] args)throws Exception {
  OracleDataSource ods = new OracleDataSource();
//  ods.setURL("jdbc:oracle:thin:@localhost:1521:orcl");
//  ods.setUser("scott");
//  ods.setPassword("tiger");
  ods.setURL("jdbc:oracle:thin:scott/123@localhost:1521:orcl");
  
  Connection conn = ods.getConnection();
  System.out.println("连接成功，连接为："+conn);
  conn.close();
 }
}

2.嵌入sql语句（假设有张表emp，有属性：empno，ename等）：

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

public class TestConnection {

 public static void main(String[] args)throws ClassNotFoundException,SQLException {
  //4要素
  String driverName = "oracle.jdbc.driver.OracleDriver";
  driverName = "oracle.jdbc.OracleDriver";
  String url = "jdbc:oracle:thin:@localhost:1521:orcl";
  String username = "scott";
  String password = "123";
  
  //注册驱动获得连接
  Class.forName(driverName);
  Connection conn = DriverManager.getConnection(url,username,password);
   
  //获得语句对象
  Statement stmt = conn.createStatement();
  
  //发送sql语句
  String sql = "select empno,ename,sal from emp";
  ResultSet rs = stmt.executeQuery(sql);
  
  //解析结果
  while(rs.next()){
   String empno = rs.getString(1);
   String ename = rs.getString("ename");
   String sal = rs.getString(3);
   System.out.println(empno+" "+ename+" "+sal);
  }
  
  rs.close();
  stmt.close();
  conn.close();
 }
}