Question

我正在寻找一种方法来验证用户输入的数字是否与存储在数据库中的数据相对应。例如。如果用户输入'5132'，它会将特定列中的所有数据加载到数组中，然后我将循环该数据并将输入与其进行比较，以期找到匹配。

简单地说：如何将数据库（结果集）中的数据解析为int数组？

我试图获得的一个简单例子

String s = JOptionPane.showInputDialog(...);
int intS = Integer.parseInt(s);
boolean correct = false;

Get database info
count++; //for every data entry

int TagNumber [] = new int [count];

for (int i=0;i<count;i++) {
 if (intS == TagNumber[i]) {
  correct =true;
  break;
 }
}

Answer 1

如果您确实要从数据库加载值并检查用户的特定值，那么您可以使用二进制搜索，否则您也可以使用SQL查询。

下面是一个实现（二进制搜索），用于在Array中查找值。

public class BinarySearch {

    public static void main(String[] a) {
        int[] numArray = {5,6,10,11,19,18,30,25,88,44,55,1,3};
        Arrays.sort(numArray);
        // performing a binary search - here 100 is the element that you want 
            // to search in your array
        System.out.println(searchElement(numArray, 100));
    }

    private static int searchElement(int[] sortedArray, int element) {

        int first = 0;
        int upto  = sortedArray.length;

        while (first < upto) {
            int mid = (first + upto) / 2;  // Compute mid point.
            if (element < sortedArray[mid]) {
                upto = mid;       // repeat search in bottom half.
            } else if (element > sortedArray[mid]) {
                first = mid + 1;  // Repeat search in top half.
            } else {
                return sortedArray[mid];       // Found it. You can return the position or the element
            }
        }
        return -1;    // The element is not in the array
    }
}

数据库功能

public class RetrieveValues {
    public static void main(String args[]) throws SQLException {
        Connection conn = null;
        Statement select = null;
        try {
            Class.forName("com.somejdbcvendor.TheirJdbcDriver");
            conn = DriverManager.getConnection(
                            "jdbc:somejdbcvendor:other data needed by some jdbc vendor",
                            "myLogin", "myPassword");
            select = conn.createStatement();
            ResultSet result = select
                    .executeQuery("SELECT Element FROM TestTable");

            List<Integer> elementList = new ArrayList<Integer>();
            while (result.next()) { // process results one row at a time
                elementList.add(result.getInt(1));
            }
            // convert to int array

            convertIntegers(elementList);

        } catch (SQLException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } finally {
            select.close();
            conn.close();
        }
    }

    public static int[] convertIntegers(List<Integer> elemIntegers)
    {
        int[] elements = new int[elemIntegers.size()];
        for (int i=0; i < elements.length; i++)
        {
            elements[i] = elemIntegers.get(i).intValue();
        }
        return elements;
    }
}

如何将Access数据库中的数据加载到int数组中？

1 个答案: