本文介绍了生成从 1 到特定值的数据的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我要生成这样的结果假设我有这些记录
I am going to generate a result like this suppose I have this records
Salah 3
John 2
我会期待这个
Salah
Salah
Salah
John
John
推荐答案
一种方法，如果您总是对 n 使用 small 值，则使用 rCTE:
One method, if you always have a small value for n is to use a rCTE:
WITH rCTE AS(
SELECT [Name],
N,
1 AS I
FROM dbo.YourTable
UNION ALL
SELECT [Name],
N,
I + 1
FROM rCTE
WHERE I < N)
SELECT [Name]
FROM rCTe
ORDER BY [Name] DESC;
如果您有更大的数字，请使用性能更好的 Tally.我在这里使用内联:
If you have much larger numbers, use a more performamt Tally. I use an inline here:
WITH N AS(
SELECT N
FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL))N(N)),
Tally AS(
SELECT --TOP (SELECT MAX(N) FROM dbo.YourTable) --Limits the number of rows, which could also provide a performance benefit if you only sometimes have large numbers
ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS I
FROM N N1, N N2, N N3) --1000 rows, add more cross joins for more rows
SELECT [Name]
FROM dbo.YourTable YT
JOIN Tally T ON YT.N >= T.I
ORDER BY YT.[Name] DESC;
db<>fiddle
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