Question

我有问题。我想通过使用来自其他查询列的值来减去查询的列值。

表格

import java.util.Stack;

public class StackSorting {

    public static void main(String[] args) {
        Stack<Integer> stack = new Stack<Integer>();

        stack.push(12);
        stack.push(100);
        stack.push(13);
        stack.push(50);
        stack.push(4);

        System.out.println("Elements on stack before sorting: "+ stack.toString());

        stack = sort(stack);

        System.out.println("Elements on stack after sorting: "+ stack.toString());

    }

    private static Stack<Integer> sort(Stack<Integer> stack) {

        if (stack.isEmpty()) {
            return null;
        }

        Stack<Integer> sortedStack = new Stack<Integer>();

        int element = 0;
        while(!stack.isEmpty()) {
            if (stack.peek() <= (element = stack.pop())) {
                if (sortedStack.isEmpty()) {
                    sortedStack.push(element);
                } else {
                    while((!sortedStack.isEmpty()) && sortedStack.peek() > element) {
                        stack.push(sortedStack.pop());
                    }
                    sortedStack.push(element);
                }
            }
        }

        return sortedStack;
    }
}

表损坏股票

ITEM  BOX  PLASTIC  
ABC     2      0  
DEF     0     15  
GHI     1      5  
JKL     0     10

预期结果（现货）

ITEM  BOX  PLASTIC  
DEF    0     15  
GHI    1      0  
JKL    0      5

我尝试使用NOT IN SQL语句，但只能为所有3列隐藏相同的值。

什么SQL语句适合于减去每个列值而不显示任何记录（如果BOX＆amp; PLASTIC是零。

Answer 1

执行left join检查可用性

select s.ITEM, IIF(s.box-ds.box is null, s.box, s.box-ds.box) BOX,
               IIF(s.plastic-ds.plastic is null, s.plastic, s.plastic-ds.plastic) PLASTIC  
from STOCK s
left join DAMAGEDSTOCK ds on ds.item = s.item
where IIF(s.box-ds.box is null, 1, s.box-ds.box) <> 0 OR
      IIF(s.plastic-ds.plastic is null, 1, s.plastic-ds.plastic) <> 0

从其他查询中减去MS-Access查询的列值

1 个答案: