大约有 48,000 项符合查询结果（耗时：0.0696秒） [XML]
Using group by on multiple columns
..., to do with who is attending what subject at a university:
Table: Subject_Selection
+---------+----------+----------+
| Subject | Semester | Attendee |
+---------+----------+----------+
| ITB001 | 1 | John |
| ITB001 | 1 | Bob |
| ITB001 | 1 | Mickey |
| ITB001 ...
How important is the order of columns in indexes?
I've heard that you should put columns that will be the most selective at the beginning of the index declaration. Example:
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How to set variables in HIVE scripts
...riable substitution.
e.g.
hive> set CURRENT_DATE='2012-09-16';
hive> select * from foo where day >= ${hiveconf:CURRENT_DATE}
similarly, you could pass on command line:
% hive -hiveconf CURRENT_DATE='2012-09-16' -f test.hql
Note that there are env and system variables as well, so you can r...
Select columns from result set of stored procedure
...stored procedure that returns 80 columns, and 300 rows. I want to write a select that gets 2 of those columns. Something like
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How to order by with union in SQL?
Is it possible to order when the data is come from many select and union it together? Such as
8 Answers
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Postgres manually alter sequence
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The parentheses are misplaced:
SELECT setval('payments_id_seq', 21, true); # next value will be 22
Otherwise you're calling setval with a single argument, while it requires two or three.
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How to keep onItemSelected from firing off on a newly instantiated Spinner?
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I would have expected your solution to work -- I though the selection event would not fire if you set the adapter before setting up the listener.
That being said, a simple boolean flag would allow you to detect the rogue first selection event and ignore it.
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Oracle SELECT TOP 10 records
I have an big problem with an SQL Statement in Oracle. I want to select the TOP 10 Records ordered by STORAGE_DB which aren't in a list from an other select statement.
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How do I execute a stored procedure once for each row returned by query?
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declare @field1 int
declare @field2 int
declare cur CURSOR LOCAL for
select field1, field2 from sometable where someotherfield is null
open cur
fetch next from cur into @field1, @field2
while @@FETCH_STATUS = 0 BEGIN
--execute your sproc on each row
exec uspYourSproc @field1, @fiel...
Search for selection in vim
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Check this Vim tip: Search for visually selected text
Or you can simply yank the selected text with y and go to search mode /, then you can paste the last yanked text with Ctrl+R 0
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