java - 无法使用 Java 访问第二个 MYSQL 数据库

Question

在java中连接到第二个MYSQL数据库时有什么特别需要注意的吗？

我查询一个数据库 db1 就好了，但是当我切换到一个重复的数据库 db2 并运行相同的查询时在 eclipse 中运行时，程序只是说“已终止”，没有任何输出。

Class.forName("com.mysql.jdbc.Driver").newInstance();
                    Connection con = DriverManager.getConnection
    ("jdbc:mysql://localhost/db2", "root", "password");
                    con.setReadOnly(true);
                    Statement stmt = con.createStatement();

                    ResultSet res = stmt.executeQuery("query that worked for db1");

    //then do stuff with res that printed out the grabbed 
//results successfully for db1`

Answer 1

Connection connection = null;
try {
// Load the JDBC driver
Class.forName("com.mysql.jdbc.Driver");
// Create a connection to the database
String serverName = "localhost";
String mydatabase = "db2";
String url = "jdbc:mysql://" + serverName +  "/" + mydatabase; // JDBC url
String username = "root";
String password = "password";
connection = DriverManager.getConnection(url, username, password);
} catch (ClassNotFoundException e) {
// Could not find the database driver
} catch (SQLException e) {
// Could not connect to the database
} finally {
System.out.println("Closing the connection.");
if (connection != null) try { connection.close(); } catch (SQLException ignore) {}
}

捕获异常并确保 Mysql 驱动程序位于类路径中。让我们知道您看到的异常消息，以便我们可以更好地解决您的问题。