Question

需要在下面的表1中计算field3，根据以下规则比较当前记录中的字段值和当前+ n毫秒（t0 +nms）的记录

WHEN type = 0 , look at record at t0 + 8ms, IF field2@t8 = field2@t0 && field1@t8 = field1@t0 + 1 THEN 1 ELSE 0

WHEN type = 1,look at record at t0 + 16ms , IF field2@t16 = field2@t0 && field1@t16 = field2@t0 + 5 THEN 1 ELSE 0

IF there is no record at t0+8ms for type=0 or no record at t0+16ms in case of type=1 THEN 0

表1

   Time             type     field1   field2    field3
   09:37.43.745       0      0          0       0 # for record at t0 + 8ms - xx.753 , field2 is SAME, but field1 is not field1@t0 +1
   09:37.43.746       0      0          1       1 # for record at t0 + 8ms - xx.754, field2 is SAME, field1 is incremented by 1
   09:37.43.747       0      0          2       0 # no record at t0 + 8ms
   09:37.43.748       0      0          3       1 # for record at t0 + 8ms - xx.756, field2 is SAME, field1 is incremented by 1
   09:37.43.749       0      0          4       0 # no record at t0 + 8ms

   09:37.43.753       0      0          0       0 # no record at t0 + 8ms
   09:37.43.754       0      1          1       0 # for record at t0 + 8ms - xx.772, field2 is SAME, but field1 is not field1@t0 + 1
-- 09:37.43.755/757 - no records 
   09:37.43.756       0      1          3       0 # no record at t0 + 8ms

   09:37.43.762       0      0          1       0 # no record at t0 + 8ms

   09:37.43.772       1      0          0       1 # for record at t0 + 16ms - xx.788, field2 is SAME AND field1 is incremented by 5    
   09:37.43.776       1      0          1       0 # for record at t0 + 16ms - xx.792, field2 is SAME BUT field1 is NOT incremented by 5  
   09:37.43.780       1      0          2       0 # no record at t0 + 16ms
   09:37.43.788       1      5          0       0 # no record at t0 + 16ms
   09:37.46.792       1      0          1       0 # no record at t0 + 16ms
-- 09:37.46.796  - no records

Answer 1

我认为您正在寻找类似下面的内容。我开始将你的英语翻译成SQL。

select t1.Time, 
       t1.Type,
       t1.Field1, 
       t1,Field2
       isnull(
         case when t2.field2 = t1.field2 and t2.field1 = t1.field1 + IIF(t1.Type=0, 1, 5) 
              then 1 else 0 end, 0) as Field3
        from table1 as t1
        left join table1 as t2
        on case t1.type when 0 then DATEADD(millisecond, 8, t1.Time) 
                        when 1 then DATEADD(millisecond, 16, t1.Time) end = t2.Time

Answer 2

如果不要求性能，那么可以通过临时表和游标

来完成

声明@table 将数据插入@table

声明游标

循环游标{计算field3并插入@table}

SQL - 在n毫秒后基于当前记录字段和字段计算新字段

2 个答案: