Java中的数据库查询

Question

如何连接MySQL数据库并执行查询？

Answer 1

首先获取JDBC驱动程序,例如mysql的Connector/J - 将jar添加到项目中.然后,您可以访问如下数据库:

公共类mysqlTest {

public static void main(String[] args) {
    String driver = "com.mysql.jdbc.Driver";
    String protocol = "jdbc:mysql://localhost/";
    String database = "database";
    String username = "mysqlUsername";
    String password = "mysqlPassword";

    Properties props = new Properties();
    props.put("user", username);
    props.put("password", password);

    Connection conn;
    Statement s;
    ResultSet rs;

    String createTableStatment = "CREATE TABLE test ( `id` INTEGER NOT NULL)";
    String insertStatment = "INSERT INTO test VALUES(1)";
    String selectQuery = "SELECT * FROM test";

    try {
        Class.forName(driver).newInstance();
    } catch (InstantiationException e) {
        e.printStackTrace();
    } catch (IllegalAccessException e) {
        e.printStackTrace();
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    }

    try {
        conn = DriverManager.getConnection(protocol + database,props);
        conn.setAutoCommit(true);
        s = conn.createStatement();
        s.execute(createTableStatment);
        s.execute(insertStatment);
        rs = s.executeQuery(selectQuery);
        while (rs.next()){
            System.out.println("id = "+rs.getString("id"));
        }
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

}