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java连接数据库步骤

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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