java数据库问题，跟着教材走，所以一直在用Access, 如果用自带的 jdk自带的数据库，驱动

发布网友发布时间：2022-05-29 07:41

共1个回答

热心网友时间：2023-10-11 10:55

JDK自带的数据库，你指的是Derby吧，JDK6之后自带的微型数据库。默认安装之后会放在jdk下面的db包中，你可看看下面的示例代码：

try { // load the driver
    Class.forName("org.apache.derby.jdbc.EmbeddedDriver").newInstance();             System.out.println("Load the embedded driver");
   Connection conn = null;
   Properties props = new Properties();
   props.put("user", "user1");
   props.put("password", "user1");
   //create and connect the database named helloDB
   conn=DriverManager.getConnection("jdbc:derby:helloDB;create=true", props);
   System.out.println("create and connect to helloDB");
   conn.setAutoCommit(false);
   // create a table and insert two records
  Statement s = conn.createStatement();
  s.execute("create table hellotable(name varchar(40), score int)");
System.out.println("Created table hellotable");
s.execute("insert into hellotable values('Ruth Cao', 86)");
s.execute("insert into hellotable values ('Flora Shi', 92)");
// list the two records
ResultSet rs=s.executeQuery("SELECT name, score FROM hellotable ORDER BY score");
System.out.println("name\t\tscore");
while(rs.next()) {
  StringBuilder builder = new StringBuilder(rs.getString(1));
  builder.append("\t");
  builder.append(rs.getInt(2));
  System.out.println(builder.toString());
  }
  // delete the table
  s.execute("drop table hellotable");
  System.out.println("Dropped table hellotable");
  rs.close();
  s.close();
  System.out.println("Closed result set and statement");
  conn.commit();
  conn.close();
  System.out.println("Committed transaction and closed connection");
  try { // perform a clean shutdown
  DriverManager.getConnection("jdbc:derby:;shutdown=true");
   } catch (SQLException se) {
      System.out.println("Database shut down normally");
       }
       }catch(Exception ex){}
       System.out.println("SimpleApp finished");

追问非常感谢，请问关于
conn=DriverManager.getConnection("jdbc:derby:helloDB;create=true"
里的括号里最后一语句 create=true 是什么意思，我以为 getConnetion就一个参数

追答create=true表示如果数据库不存在则创建