沒有數據可用

Question

我是新來的Java，我試圖打印在表格

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

的所有數據，並得到

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

Answer 1

你需要調用rs.getString("...")之前調用rs.next()。

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

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

---

如果你希望只排1，那麼你也可以這樣做：

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

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