Connection : 连接数据库并担任传送数据的任务
* Statement : 执行SQL语句
* ResultSet :保存Statement执行后产生的查询结果
1 .注册驱动
Class.forName(JDBC驱动类);
2 .获取数据库连接
Connection con = DriverManager.getConnection(JDBC url,数据库用户名,密码);
3 .获得 Statement对象
Statement stmt = con.createStatement();
4 .执行SQL语句
ResultSet rs = stmt.executeQuery( select a,b from table );
5 .处理执行结果
while (rs. next ()){
int x = rs.getInt("a");
String s = rs.getString("b");
* 数据类型要相匹配
}
6 .释放资源
1 .rs. close ();
2 .stmt. close ();
3 .con. close ();
* 顺序倒过来依次关闭
实例:
Java使用PreparedStatement接口插入数据库信息
public class PreparedStatementDemo01 {
public static final String DBDRIVER = "org.gjt.mm.mysql.Driver";
public static final String DBURL = "jdbc:mysql: // localhost: 3306 / ";
public static final String DBUSER = "root";
public static final String DBPASS = "root";
public static void main(String args [] ) throws ParseException, ClassNotFoundException, SQLException
{
Connection conn = null ; // 数据库连接
PreparedStatement pstmt = null ; // 数据库操作
Statement stmt = null ;
ResultSet rs = null ; // Rs接口
String name = "黄鹏";
String password = " 1598741 ";
int age = 21 ;
String sex = "男";
String birthday = " 1992 - 04 - 30 ";
Date temp = null ;
temp = new SimpleDateFormat("yyyy - MM - dd").parse(birthday);
java.sql.Date bri = new java.sql.Date( temp .getTime());
// 创建数据库操作语句
String sql1 = " CREATE DATABASE MyDemo;";
// 选择使用哪个数据库的语句
String sql2 = " USE MyDemo;";
// 创建数据库表操作语句
String sql3 = " CREATE TABLE user (name varchar ( 20 ) primary key ,password varchar ( 20 ),age int ,sex varchar ( 10 ),birthday Date);";
// 查询数据库语句
String sql5 = " select * from user ;";
// 用PreparedStatement执行的插入语句
String sql4 = " INSERT INTO user (name,password,age,sex,birthday) VALUES (?,?,?,?,?);";
// 加载驱动程序
Class.forName(DBDRIVER);
// 连接mysql数据库
conn = DriverManager.getConnection(DBURL,DBUSER,DBPASS);
// 实例化PreparedStatement
pstmt = conn.prepareStatement(sql4);
// 设置第一个?内容
pstmt.setString( 1 , name);
// 设置第二个?内容
pstmt.setString( 2 , password);
// 设置第三个?内容
pstmt.setInt( 3 , age);
// 设置第四个?内容
pstmt.setString( 4 ,sex);
// 设置第五个?内容
pstmt.setDate( 5 , bri);
// 执行数据库更新,不需要sql
stmt = conn.createStatement();
stmt. execute (sql1);
stmt. execute (sql2);
stmt. execute (sql3);
pstmt.executeUpdate();
rs = stmt.executeQuery(sql5);
// 向控制台输出信息
while (rs. next ())
{
String QueryName = rs.getString("name");
String QueryPwd = rs.getString("password");
int QueryAge = rs.getInt("age");
String QuerySex = rs.getString("sex");
Date QueryDate = rs. getDate ("birthday");
System.out.println("name:" + QueryName + " pwd:" + QueryPwd + " " + QueryAge + " sex:" + QueryPwd + " date:" + QueryDate);
}
pstmt. close ();
conn. close ();
}
}
java连接数据库步骤
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