June 15, 2013 at 12:47 am
I am in the process of learning how to put together simple programs to iterate over a table dataset and report various information from that table. To do this I am using a temporary table. I though have not figured out yet how to program a second pass through the temporary table. Can someone help me with the principles I am missing in this. I am working through a book but haven't gotten there yet. Just a little impatient and want to know the solution before reading through it. Here is my dataset, code and results. My results do not reflect sorted results which I will correct, I would like to know why I cannot get the "TYPE" field populated.
YearMonthDayHourMinuteSecondMilisecondAskBidAskVolumeBidVolume
201301020133290951.322771.322641.52.48
201301020133299551.322771.322641.52.48
201301020133303151.322771.322661.51.5
201301020133308591.322771.322641.52.48
201301020133313251.322771.322661.51.5
201301020133316251.322771.322661.52.25
201301020133325061.322771.322661.51.5
201301020133328551.322771.322661.51.5
201301020133368651.322781.322641.52.48
201301020133530351.322781.322662.251.5
201301020133551051.322781.322662.251.5
201301020133560961.322781.322662.251.5
201301020134040221.322751.322662.251.5
201301020134042161.322741.322631.351.88
201301020134047541.322751.322631.51.88
USE
EURUSD
GO
DECLARE @status char(6),
@Volfloat(5)
DECLARE @TestTable TABLE (Type char(6), Volume float(4))
BEGIN
INSERT INTO @TestTable (Volume)
SELECT BidVolume
FROM EURUSD#1
END
BEGIN
SELECT @Vol = Volume FROM @TestTable
IF @VOL > 0
INSERT INTO @TestTable (Type)
VALUES('OK')
ELSE
INSERT INTO @TestTable (Type)
VALUES('NOTOK')
SELECT Volume, Type
FROM @TestTable
END
Query Results----------------------------------
VolumeType
NULLOK
2.25NULL
1.88NULL
1.65NULL
2.4NULL
1.65NULL
1.5NULL
1.5NULL
1.65NULL
1.65NULL
June 15, 2013 at 3:59 pm
I'm guessing here because your requirements aren't quite clear. What you seem to want to do is to set the Type column to either 'OK' or 'NOTOK', based on whether the Volume column is greater than zero or not. But what you are doing with the
SELECT @Vol = Volume FROM @TestTable
is getting the Volume of an arbitrary row in @TestTable, and then adding a new row to @TestTable, where you only insert a value for the Type column. What you really intend to do (if I am not mistaken) can be accomplished like this:
UPDATE @TestTable
SET Type =
CASE
WHEN Volume > 0 THEN 'OK'
ELSE 'NOTOK'
END
This code hasn't been tested, but it should do what I understand it should do.
BTW, it always helps adding a set of DDL statements that create test tables, plus a set of INSERT statements with test data, so that we (being volunteers) don't have to spend extra time creating those ourselves in order to help you out.
Regards,
Jan
June 15, 2013 at 4:01 pm
basically this chunk of code
SELECT @Vol = Volume FROM @TestTable
IF @VOL > 0
INSERT INTO @TestTable (Type)
VALUES('OK')
ELSE
INSERT INTO @TestTable (Type)
VALUES('NOTOK')
will insert one row into @TestTable, which will have NULL in the Volume column (because you insert doesn't specify a value for that column) and either OK or NOTOK in the type column (depending on what the last record the select statement found in the table had in that column).
If you change that code to something like
UPDATE @TestTable
Set Type '=CASE when @Vol > 0 THEN 'OK' ELSE 'NOTOK' END
-- where 1 = 1 note that this line is commented out
SO (1) specify which rows you want to change in the UPDATE statement (here it's all rows, which is the default, so you don't need a WHERE clause).
AND (2) if you are trying to update rows you already inserted (as you are here) use UPDATE, not INSERT (which inserts new rows).
Tom
June 15, 2013 at 4:03 pm
June 15, 2013 at 9:48 pm
Jan Van der Eecken & L'Eomot Inverse'
Thank you for your time in answering my request and the clear direction.
In future posts I will follow forum protocol. Everyone's time is valuable.
June 16, 2013 at 1:00 am
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