JDBC连接数据库（续）--完成对数据库的CRUD操作

package com.hyneng.jdbc;

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

public class CRUD {

/**
* @param args
* @throws SQLException
*/
public static void main(String[] args) throws SQLException {
//create();
read();
//update();
//delete();

}

static void delete() throws SQLException {
Connection conn = null;
Statement st = null;
ResultSet rs = null;
try {
// 2.建立连接
conn = JdbcUtils.getConnection();
// 3.创建执行SQL的语句
st = conn.createStatement();
String sql="delete from user where id>3";
// 4.执行语句
int i=st.executeUpdate(sql);
System.out.println("i="+i);
} finally {
JdbcUtils.free(rs, st, conn);
}
}


static void update() throws SQLException {
Connection conn = null;
Statement st = null;
ResultSet rs = null;
try {
// 2.建立连接
conn = JdbcUtils.getConnection();
// 3.创建执行SQL的语句
st = conn.createStatement();
String sql="update user set money=money+10";
// 4.执行语句
int i=st.executeUpdate(sql);
System.out.println("i="+i);
} finally {
JdbcUtils.free(rs, st, conn);
}
}


static void create() throws SQLException {
Connection conn = null;
Statement st = null;
ResultSet rs = null;
try {
// 2.建立连接
conn = JdbcUtils.getConnection();
// 3.创建执行SQL的语句
st = conn.createStatement();
String sql="insert into user(name,birthday,money) value('name1','1987-07-04',400)";
// 4.执行语句
int i=st.executeUpdate(sql);
System.out.println("i="+i);
} finally {
JdbcUtils.free(rs, st, conn);
}
}

static void read() throws SQLException {
Connection conn = null;
Statement st = null;
ResultSet rs = null;
try {
// 2.建立连接
conn = JdbcUtils.getConnection();
// 3.创建执行SQL的语句
st = conn.createStatement();

// 4.执行语句
rs = st.executeQuery("select id,name,birthday,money from user");

// 5.处理结果
while (rs.next()) {
System.out.println(rs.getObject("id") + "\t"
+ rs.getObject("name") + "\t"
+ rs.getObject("birthday") + "\t"
+ rs.getObject("money"));
}
} finally {
JdbcUtils.free(rs, st, conn);
}
}

}