SQLServer 默认递归上限问题及三种可靠解决方案

-- 你的原始递归CTE查询
WITH ts AS (
  SELECT CAST('2025-10-01T00:00:00' AS datetime2) AS bucket
  UNION ALL
  SELECT DATEADD(minute, 10, bucket)
  FROM ts
  WHERE bucket < CAST('2025-10-02T00:00:00' AS datetime2)
)
SELECT *
FROM ts
OPTION (MAXRECURSION 0);  -- 0 = 不限制（生产慎用，需确保 WHERE 正确）

-- 建表：包含从 0 开始的连续整数
CREATE TABLE dbo.Numbers (n int NOT NULL PRIMARY KEY);
-- 生成足够多的行（示例：生成 1,000,000 行）
;WITH E1(N) AS (SELECT 1 UNION ALL SELECT 1),
E2 AS (SELECT 1 FROM E1 a CROSS JOIN E1 b),        -- 4
E4 AS (SELECT 1 FROM E2 a CROSS JOIN E2 b),        -- 16
E8 AS (SELECT 1 FROM E4 a CROSS JOIN E4 b),        -- 256
E16 AS (SELECT 1 FROM E8 a CROSS JOIN E8 b),       -- 65,536
E32 AS (SELECT 1 FROM E16 a CROSS JOIN E16 b)      -- ~4B（谨慎）
INSERT INTO dbo.Numbers(n)
SELECT TOP (1000000) ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) - 1
FROM E32;

DECLARE @start datetime2 = '2025-10-01T00:00:00';
DECLARE @end   datetime2 = '2025-10-02T00:00:00';
DECLARE @step_min int = 5; -- 间隔：5分钟
WITH ts AS (
  SELECT DATEADD(minute, n * @step_min, @start) AS bucket
  FROM dbo.Numbers
  WHERE DATEADD(minute, n * @step_min, @start) < @end  -- 通常用 [start, end)
),
agg AS (
  -- 将事实表事件对齐到 5 分钟桶
  SELECT DATEADD(minute, DATEDIFF(minute, 0, event_time) / @step_min * @step_min, 0) AS bucket_5m,
         COUNT(*) AS c
  FROM dbo.EventLog
  WHERE event_time >= @start AND event_time < @end
  GROUP BY DATEADD(minute, DATEDIFF(minute, 0, event_time) / @step_min * @step_min, 0)
)
SELECT ts.bucket,
       ISNULL(agg.c, 0) AS event_count
FROM ts
LEFT JOIN agg ON ts.bucket = agg.bucket_5m
ORDER BY ts.bucket;

DECLARE @start datetime2 = '2025-10-01T00:00:00';
DECLARE @end   datetime2 = '2025-10-02T00:00:00';
DECLARE @step_min int = 15;
;WITH N AS (
  SELECT TOP (1000000) ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) - 1 AS n
  FROM sys.all_objects a CROSS JOIN sys.all_objects b
),
ts AS (
  SELECT DATEADD(minute, n * @step_min, @start) AS bucket
  FROM N
  WHERE DATEADD(minute, n * @step_min, @start) < @end
),
agg AS (
  SELECT DATEADD(minute, DATEDIFF(minute, 0, event_time) / @step_min * @step_min, 0) AS bucket_15m,
         COUNT(*) AS c
  FROM dbo.EventLog
  WHERE event_time >= @start AND event_time < @end
  GROUP BY DATEADD(minute, DATEDIFF(minute, 0, event_time) / @step_min * @step_min, 0)
)
SELECT ts.bucket,
       ISNULL(agg.c, 0) AS event_count
FROM ts
LEFT JOIN agg ON ts.bucket = agg.bucket_15m
ORDER BY ts.bucket;