Do I need a recursive CTE to update a table that relies on itself?

问题

I need to apologize for the title. I put a lot of thought into it but didn't get too far.

I have a table that looks like this:

+--------------------------------------+--------------------------------------+--------------------------------------+--------------------------------------+--------+
|              accountid               |             pricexxxxxid             |              accountid               |             pricelevelid             | counts |
+--------------------------------------+--------------------------------------+--------------------------------------+--------------------------------------+--------+
| 36B077D4-E765-4C70-BE18-2ECA871420D3 | 00000000-0000-0000-0000-000000000000 | 36B077D4-E765-4C70-BE18-2ECA871420D3 | F43C47CE-28C6-42E2-8399-92C58ED4BA9D |      1 |
| EBC18CBC-2D2E-44CB-B36A-0ADE9E2BDE9F | 00000000-0000-0000-0000-000000000000 | EBC18CBC-2D2E-44CB-B36A-0ADE9E2BDE9F | 3BEEA9D3-F26B-47E4-88FA-A2AA366980ED |      1 |
| 8DC8D0FC-3138-425A-A922-2F0CAC57E887 | 00000000-0000-0000-0000-000000000000 | 8DC8D0FC-3138-425A-A922-2F0CAC57E887 | F1B8AD5D-B008-4C3F-94A0-AD3F90C777D7 |      1 |
| 8F908A92-1327-4655-BAE4-C890D971A554 | 00000000-0000-0000-0000-000000000000 | 8F908A92-1327-4655-BAE4-C890D971A554 | 2E0EC67E-5F8F-4305-932E-BBF8DF83DBEC |      1 |
| 37221AAC-B885-4002-B7D9-591F8C14D019 | 00000000-0000-0000-0000-000000000000 | 37221AAC-B885-4002-B7D9-591F8C14D019 | F4A2A0CA-FDFF-4C21-AE92-D4583DC18DED |      1 |
| 66F406B4-0D9B-40B8-9A23-119EE74B00B7 | 00000000-0000-0000-0000-000000000000 | 66F406B4-0D9B-40B8-9A23-119EE74B00B7 | 204B8570-CEBA-4C72-9B72-8B9B14AF625E |      2 |
| D0168CE3-479E-439E-967C-4FF0D701291A | 00000000-0000-0000-0000-000000000000 | D0168CE3-479E-439E-967C-4FF0D701291A | 204B8570-CEBA-4C72-9B72-8B9B14AF625E |      2 |
| 57E5F6E5-0A8A-4E54-B793-2F6493DC1EA3 | 00000000-0000-0000-0000-000000000000 | 57E5F6E5-0A8A-4E54-B793-2F6493DC1EA3 | 893F9FD2-43C9-4355-AEFC-08A62BF2B066 |      3 |
+--------------------------------------+--------------------------------------+--------------------------------------+--------------------------------------+--------+

It is sorted by ascending counts.

I would like to update the pricexxxxids that are all 00000000-0000-0000-0000-000000000000 with their corresponding pricelevelid.

For example for accountid = 36B077D4-E765-4C70-BE18-2ECA871420D3 I would like the pricexxxxid to be F43C47CE-28C6-42E2-8399-92C58ED4BA9D.

After that is done, I would like all the records FOLLOWING this one where accountid = 36B077D4-E765-4C70-BE18-2ECA871420D3 to be deleted.

Another words in result I will end up with a distinct list of accountids with pricexxxxid to be assigned with the corresponding value from pricelevelid.

Thank you so much for your guidance.

回答1:

for your first case do !

update table
set pricexxxxids=pricelevelid.

if i understand your second case correctly :(delete duplicates/select distinct)?

delete from
(
select *,rn=row_number()over(partition by accountid order by accountid) from table
)x
where rn>1


--select distinct * from table

edited

select * from
(
select *,rn=row_number()over(partition by accountid order by accountid) from table
)x
where x.rn=1

updated

  SELECT accountid,pricelevelid FROM  
    (
    (SELECT *,
    Row_number() OVER ( partition BY accountid ORDER BY counts, pricelevelid ) AS Recency 
    FROM table
    )x 
   WHERE x.Recency = 1

来源：https://stackoverflow.com/questions/23751253/do-i-need-a-recursive-cte-to-update-a-table-that-relies-on-itself

标签

sql

sql-server

tsql

sql-server-2008-r2