SQL更新多行而没有硬编码的每个值

Question

我想更新数千行，但键入每个值都是耗时的

我的代码

UPDATE #table
SET city = 'New York'
WHERE city is null
AND store_id = '22'

预期结果

store_id   city      state
22        New york   NY
22        New york   NY
22        New york   NY
33         LA        CA
33         LA        CA

如何修改代码，这样我就不必每次都输入“ New York”等内容？谢谢

Answer 1

这就是我的想法，但是我相信可能会有更优化的方法来实现：

WITH cteCities(store_id, city, state) AS
    (SELECT DISTINCT store_id, city, state FROM #table WHERE city IS NOT NULL)
UPDATE #table
SET city = cte.city, state = cte.state
FROM cteCities cte
INNER JOIN #table
ON cte.store_id = #table.store_id
WHERE #table.city IS NULL

Answer 2

CREATE TABLE #t (store_id varchar(20),city varchar(20),[state] varchar(20))
INSERT INTO #t VALUES
('22', 'new', 'NY'),
('22', null, null),
('22', null, null),
('33', null, null),
('33', 'LA', 'CA')
;


WITH CTE AS 
(
    SELECT DISTINCT store_id, city, [state] FROM #t WHERE city IS NOT NULL
)
UPDATE #t
SET city = CTE.city, [state] = CTE.[state]
FROM CTE
INNER JOIN #t
ON CTE.store_id = #t.store_id
WHERE #t.city IS NULL