Question

So I have a couple SQL commands that I basically want to make a proc, but while doing this, I’d like to optimize them a little bit more.

The first part of it is this:

select tr_reference_nbr
from cfo_daily_trans_hist
inner join cfo_fas157_valuation on fv_dh_daily_trans_hist_id = dh_daily_trans_hist_id 
inner join cfo_tran_quote on tq_tran_quote_id = dh_tq_tran_quote_id
inner join cfo_transaction on tq_tr_transaction_id = tr_transaction_id
inner join cfo_fas157_project_valuation ON fpv_fas157_project_valuation_id = fv_fpv_fas157_project_valuation_id AND fpv_status_bit = 1
group by tr_reference_nbr, fv_dh_daily_trans_hist_id
having count(*)>1

This query returns to me which tr_reference_nbr‘s exist that have duplicate data in our system, which needs to be removed. After this is run, I run this other query, copying and pasting in the tr_reference_nbr one at a time that the above query gave me:

select 
tr_reference_nbr , dh_daily_trans_hist_id ,cfo_fas157_project_valuation.*,
cfo_daily_trans_hist.* ,
cfo_fas157_valuation.* 
from cfo_daily_trans_hist
inner join cfo_fas157_valuation on fv_dh_daily_trans_hist_id = dh_daily_trans_hist_id 
inner join cfo_tran_quote on tq_tran_quote_id = dh_tq_tran_quote_id
inner join cfo_transaction on tq_tr_transaction_id = tr_transaction_id
iNNER JOIN cfo_fas157_project_valuation ON fpv_fas157_project_valuation_id = fv_fpv_fas157_project_valuation_id
where
tr_reference_nbr in
(
[PASTEDREFERENCENUMBER]
)
and fpv_status_bit = 1
order by dh_val_time_stamp desc

Now this query gives me a bunch of records for that specific tr_reference_nbr. I then have to look through this data and find the rows that have a matching (duplicate) dh_daily_trans_hist_id. Once this is found, I look and make sure that the following columns also match for that row so I know they are true duplicates: fpv_unadjusted_sponsor_charge, fpv_adjusted_sponsor_charge, fpv_unadjusted_counterparty_charge, and fpv_adjusted_counterparty_charge.

If THOSE all match, I then look to yet another column, fv_create_dt, and make sure that there is less then a minute difference between the two timestamps there. If there is, I run yet another query on the row that was stored EARLIER, which looks like this:

begin tran
update cfo_fas157_valuation set fpv_status_bit = 0 where fpv_fas157_project_valuation_id = [IDRECIEVEDFROMTHEOTHERTABLE]
commit

As you can see, this is still a very manual process even though we do have a few queries written, but I’m trying to find a solution to where we can just run one query, and it would basically do EVERYTHING except for the final query. So basically something that would provide to us a few fpv_fas157_project_valuation_id‘s that need to be updated.

From looking at these queries, do any of you guys see an easy way to combine all this? I’ve been working on it all day and can’t seem to get something to run. I feel like I keep screwing up the joins and stuff.

Thanks!

Answer 1

You can combine these queries in multiple ways:

• use temporary tables to store results of queries – suitable for stored procedure
• use table variables to store results of queries – suitable for stored procedure
• use Common Table Expressions (CTEs) to store results of queries – suitable for single query

Once You have them in separate tables/variables/CTEs You can easily join them.

Then You have to do one more thing, and that is to find difference in datetime in two consecutive rows. There is a trick to do this:

1. use ROW_NUMBER() to add a column with number of row partitioned by grouping fields (tr_reference_nbr, … ) ordered by fv_create_dt
2. do a self join on A.ROW_NUMBER = B.ROW_NUMBER + 1
3. check the difference between A.fv_create_dt and B.fv_create_dt to filter the rows with difference less than a minute

Just do a good test of your self-join to make sure You filter only rows You need to filter.

If You still have problems with this, don’t hesitate to leave a comment.

Interesting note: SQL Server Denali has T-SQL enhancements LEAD and LAG to access subsequent and previous row without self-joins.