Wednesday, March 21, 2012

Loop through each record and then each field within each record

I need to essentially do 2 loops. One loops through each record and then inside each record row, I want to perform an insert on each column.
Something like this maybe using a cursor or something else:
For each record in my table (I'll just use the cursor)
For each column in current record for cursor
perform some sql based on the current column value
Next
Next
So below, all I need to do is figure out how to loop through each column for the current record in the cursor

AS
DECLARE Create_Final_Table CURSOR FOR
SELECT FieldName, AcctNumber, Screen, CaseNumber, BKYChapter, FileDate, DispositionCode, BKUDA1, RMSADD2, RMSCHPNAME_1, RMSADDR_1,
RMSCITY_1, RMSSTATECD_1, RMSZIPCODE_1, RMSWORKKPHN, BKYMEETDTE, RMSCMPNAME_2, RMSADDR1_2, RMSCITY_2, RMSSTATECD_2,
RMSZIPCODE_2, RMSHOMEPHN, BARDATE, RMSCMPNAME_3, RMSADD1_2, RMSADD2_3, RMSCITY_3, RMSZIPCODE_3, RMSWORKPHN_2
FROM EBN_TEMP1
OPEN Create_Final_Table
FETCH FROM Create_Final_EBN_Table INTO @.FieldName, @.AcctNumber, @.Screen, @.CaseNumber, @.BKYChapter, @.FileDate, @.DispositionCode, @.BKUDA1, @.RMSADD2, @.RMSCHPNAME_1, @.RMSADDR_1,
@.RMSCITY_1, @.RMSSTATECD_1, @.RMSZIPCODE_1, @.RMSWORKKPHN, @.BKYMEETDTE, @.RMSCMPNAME_2, @.RMSADDR1_2, @.RMSCITY_2, @.RMSSTATECD_2,
@.RMSZIPCODE_2, @.RMSHOMEPHN, @.BARDATE, @.RMSCMPNAME_3, @.RMSADD1_2, @.RMSADD2_3, @.RMSCITY_3, @.RMSZIPCODE_3, @.RMSWORKPHN_2
WHILE @.@.FETCH_STATUS = 0
BEGIN
@.Chapter = chapter for this record
For each column in current record <- not sure how to code this part is what I'm referring to
do some stuff here using sql for the column I'm on for this row


Next
Case @.Chapter
Case 7

Insert RecoverCodeRecord
Insert Status Code Record
Insert Attorney Code Record
Case 13
Insert Record
Insert Record
Insert Record
Case 11
Insert Record
Insert Record
Insert Record
Case 12
Insert Record
Insert Record
Insert Record
END
close Create_Final_Table
deallocate Create_Final_Table

Also, if you think there is a better way to do this, let me know.

Are you inserting from EBN_TEMP1 into multiple tables? If so then you can just use series of INSERT...SELECT statements. You need to reference the column you need in each SELECT statement.|||

I have to take every record from my select, cycle through each. So let's say I cycle to the first record in my cursor. I need to then cycle through each field in that row and take that field and do something with it.

Then move on to the next row, cycle through it's fields one by one and so on till I have done this for every row in my cursor. I just don't know how to cycle and reference each column in a unique row after each iteration of my cursor's rows

What I'll be doing wtih each colum is taking the value and inserting it into another table with some other values I'll specify in a select.

|||There must be a way to do a loop to go through each field in a cursor row, but I haven't come up with any and have searched internet forever. This is shocking that nobody has ever brought this up. All they talk about is looping through a cursor's rows or just rows in general, not how to take a row and loop through to do something with every single column (field) in the row. I have a good reason for this need so please don't ask why if you're tempted to.|||

I'm not trying to be rude whatsoever but to me that's inefficient to create multiple inserts and selects. But of course you probably didn't know that those selects and inserts would be inserting the same values, only the field value is changing in the statement at each iteration. So that's why I don't want to basically rewrite the same insert and select. I just need to loop through each and move in the value to a parameter in my insert statement

|||

SQL is not a procedural language so it is best to approach the problem with a set oriented mindset. And this is often hard to do. So if you can perform the operation efficiently using DMLs alone it is much more efficient for the engine and it is also easier for you to maintain the code. Let's take an example. (You have to provide some examples as to what you are doing in the insert. You didn't answer my question about whether you are inserting into multiple tables)

insert into t1 (f1, f2)

select f1, f2 -- any computations on the columns can be done here

from tbl

....

insert into t1 (f3, f4)

select f3, f4 -- any computations on the columns can be done here

from tbl

....

So there is nothing like looping through each column. There simply isn't any construct in TSQL or similar procedural languages in RDBMSes. On the other hand if you want to unpivot the results then you can do that using UNPIVOT operator in SQL Server 2005 or use SQL again. To use SQL to unpivot the operation of converting columns to rows then you can do something like below:

-- traditional SQL way

select f1

from tbl

...

union all

select f2

from tbl

....

-- another less obvious method

select case c.c when 1 then f1 when 2 then f2 end as f

from tbl

cross join (select 1 union all select 2) as c(c)

If you do not want to repeat the query multiple times then you can define a view or inline table-valued function or temporary table or table variables and use it instead. So there are many ways to avoid duplication of code. Best is to describe your problem rather than showing procedural code since there are many ways to perform the same set of operations in SQL much more efficiently and elegantly.

|||

My insert will look lik this and all go into one table because that table will end up being the flat file I create

Insert into table1 'a1', 'b1', @.ColumnName, @.ColumnValue, 'IO'

so for each column in the row, I have to insert it as a separate record into my final table.

Yes, this is inefficient but I have to do this for our stupid ERP system which whose UI only can map updates based on individual field records from a flat file....don't ask me why, it's retarted. they will take my flat file an use it in conjunctiuon with the ERP Import GUI to do so, I just have to create the flat file. Before the process was:

1) receive txt comma delimited file from our vendor

2) Parse it out into an MS Access Table

3) Create an individual record for each column in each row and include the AccountID with it and some other static values

4) save it as a fixed length flat file

Now I'm automating this process for them using SQL Server 2005 Integration Services. My flow is like this:

1) Use Flat File Source to import the comma delimmeted txt file (650,000 records)

2) Use Conditional Split to determine which records to filter out

3) Use OLE DB Destination Editor to move in the records to a table

4) Use a SQL TASK to code the splitting out of each field of each row into a new record in my final table. The final table will be used to create the fixed length flat file in the end.

#4 is what I'm trying to do. I have to include the following fields for each record in my final table:

AccountID, 'a1', 'b1', ColumnName, ColumnValue

So in other words for each row in my table that the OLE DB added my records to, I then have to split out each column for each row into a final table including the account D for every row.

I hope this makes sense, it's not as confusing as it seems.

|||

so expanding on my last post, this may give you a sense:

Let's say the OLE DB moves my records into a table initially for step 3. The table now looks something like this:
Acct # Zip Phone Addr
11223 23232 333-444-5555 6556 Duns Rd.
12345 34343 222-444-3333 1000 Aspire Blvd.
I need to create a record using the Acct # and column for each column as well as append some other values like this into a final table. That final table will be a flat file in the end, I just need to figure out how to get this done first.
11223 23232 othervalue1 othervalue2
11223 333-444-5555 othervalue1 othervalue2
11223 6556 Duns Rd. othervalue1 othervalue2
12345 34343 othervalue1 othervalue2
12345 222-444-3333 othervalue1 othervalue2
12345 1000 Aspire Blvd. othervalue1 othervalue 2

|||If you are using SSIS then there is really no reason to denormalize the data in SQL Server. You can just do it in SSIS. Look at the foreach loop container in SSIS. This should allow you to loop through each column. If you have more questions about SSIS please post in the SQL Server Integration Services forum.|||ok, so then if I use the for each, how do I add my sql statement and have it refer to each column for the row I'm on?|||No. You get the data from the table as is and then perform the transformation on the client side. This is easier to do. For example, if you get a datareader for the results then you can use the columns collection with foreach container and loop through each column. If you post the question in the SSIS forum you will get more solutions.|||thanks so much|||

I am following your advice on an SSIS package I have that must evaluate each record. The issue I am having is that the dataReader destination is far slower then the recordset destination. Problem is I can not figure out how to get data from the record set.

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