JDBC ResultSet - 没有数据可用

Question

我是java的新手，我试图打印表中的所有数据

    Statement stmt=connection.createStatement();
    String sql ="INSERT INTO contacts(name,email)VALUES('ABC','ABC@yahoo.com')";
    stmt.execute(sql);
    ResultSet rs=stmt.executeQuery("SELECT*FROM contacts");
    System.out.println(rs.getString("name"));

得到了

Exception in thread "main" org.h2.jdbc.JdbcSQLException: No data is available [2000-173]

Answer 1

您需要在致电rs.next()之前致电rs.getString("...")。

...
ResultSet rs=stmt.executeQuery("SELECT * FROM contacts");

while(rs.next()) {
    System.out.println(rs.getString("name"));
}

如果您只期望一行，那么您也可以这样做：

...
ResultSet rs=stmt.executeQuery("SELECT * FROM contacts");

if(rs.next()) {
    System.out.println(rs.getString("name"));
}