Question

这当然是更大代码的一部分。它会编译没有问题，但是当我调用这个方法时，我得到了错误

＆＃34;＃34;附近或之后的语法错误。＆＃34;＆＃34;在stmt.executeQuery（SQL）的位置。

我真的很感激帮助！

private void Component() {
    try {
        Statement stmt = con.createStatement();
        String SQL = "SELECT component.*, stock.amount_of_component, component.price component.component_type "
                    + "FROM component JOIN stock "
                    + "ON component.id = stock.component_id "
                    + "ORDER BY component.component_type";
        ResultSet rs = stmt.executeQuery(SQL);

        rs.next();
        int id = rs.getInt("ID");
        int amount_of_component = rs.getInt("Amount");
        String name = rs.getString("Name");
        double price = rs.getDouble("Price");
        String component_type = rs.getString("Type");


       System.out.println(" " + id + amount_of_component + " " + name + " " + price + " " + component_type);

    } catch (SQLException err)
    {
        System.out.println(err.getMessage());
    }
}

Answer 1

错误，在component.price和component.component_type：

之间的查询中缺少逗号

SELECT component.*, stock.amount_of_component, component.price, component.component_type 
FROM component JOIN stock 
ON component.id = stock.component_id 
ORDER BY component.component_type

编辑：要读取整个结果集，请将此循环设置为rs.next（）

while(result.next()) {
    int id = rs.getInt("ID");
    int amount_of_component = rs.getInt("Amount");
    String name = rs.getString("Name");
    double price = rs.getDouble("Price");
    String component_type = rs.getString("Type");
    System.out.println(" " + id + amount_of_component + " " + name + " " + price + " " + component_type);
}

编辑2：要打印标题，您必须先在System.out.println(" id amount_of_component name price component_type ");之前手动执行此操作。

Answer 2

你错过了＆＃39; component.price＆＃39;之间的逗号。和＆＃39; component.component_type＆＃39;

JDBC在＃34;或附近的语法不正确。＆＃34;的executeQuery

2 个答案: