如何重复查询元素？

Question

考虑表

CREATE TABLE `contact` (
    `id`    INTEGER,
    `name`  TEXT,
    `category`  INTEGER,
    `freed` INTEGER DEFAULT 0,
    PRIMARY KEY(id)
);

我想创建这样的查询或视图，它将复制freed = 1 AND caregory IS NOT NULL行，因为这些行类别应设置为-1。应删除(category is null and freed = 1)行。

第一张图显示数据来源。第二张图片显示了期望的结果 应添加3个新行（Jin，-1,1 | Tih，-1,1 | Traph，-1,1）
1 raw被删除（Traph，null，1）

    WHERE NOT(category is null and freed = 1)
    ORDER BY category IS NULL ASC, category = -1 ASC, category ASC , name ASC

是否可以制作类似

的内容

CREATE VIEW v1 AS
SELECT s.name, s.category, s.freed
FROM contact s
CASE freed = 1 and category is not null 
    insert into v1(t.name,-1,1) 
    SELECT p.name
    FROM contact p
    WHERE s.name = p.name

Answer 1

如果您只想要这些值，那么：

select name, category, freed
from contact c
where category is null and freed = 1
union all
select name, -1, freed
from contact
where category is not null and freed = 1;

主要问题是获得正确的id值。这在SQLite中有点棘手，你的例子用＃34;回填＆＃34;数字根本不易实施。

Answer 2

所以你需要的是：

INSERT INTO CONTACT 
(SELECT Name,-1,1 FROM CONTACT
WHERE CATEGORY IS NOT NULL AND FREED = 1)

删除：

DELETE FROM CONTACT
WHERE CATEGORY IS NULL AND FREED = 1

或者如果你想在查询中那么：

SELECT Name,-1,1 FROM CONTACT
WHERE CATEGORY IS NOT NULL AND FREED = 1
UNION 
select nam,ecategory,freed
FROM CONTACT