NetBeans IDE中的组合框将不会填充从MySQL中提取的年份

Question

我有一个MySQL报价表，列名为quote_date，其中存储了报价发布的日期。我想在我的Netbeans应用程序中只选取该日期的年份来填充一个组合框。我用来获取年份的SQL语法是:

SELECT EXTRACT(YEAR FROM quote_date) AS quoteYear from quotesdb 

此语法适用于MySQL，但在Netbeans上，组合框仍然为空。没有错误发生。会出什么问题呢?

下面是我在Netbeans中实现语法的方法:

try
 {
     String sql = "SELECT EXTRACT(YEAR FROM quote_date) AS quoteYear from quotesdb";
     Class.forName("com.mysql.jdbc.Driver");
    //connection for database
    Connection conn = (Connection)
            //root and username and password for access to the database
    DriverManager.getConnection("jdbc:mysql://localhost:3306/salventri","root","password");
    //create the statement that will be used
    Statement stmt=conn.createStatement();
    ResultSet rs = stmt.executeQuery(sql); 
    while(rs.next())
    {
        String year = rs.getString("quote_date");
        //adding the quote year to the combobox
        cboQIYear.addItem(year);
    }

Answer 1

没有填充组合框的原因是在第一行:

String sql = "SELECT EXTRACT(YEAR FROM quote_date) AS quoteYear from quotesdb";

我应该从quoteYear中获得年份，但我没有更改行中的列名:

String year = rs.getString("quote_date");

一旦我将rs.getString("quote_date");更改为rs.getString("quoteYear");，组合框就会填充年份